draft-ietf-megaco-protocol-06.txt   draft-ietf-megaco-protocol-07.txt 
Internet Engineering Task Force Fernando Cuervo Internet Engineering Task Force Fernando Cuervo
INTERNET DRAFT Nortel Networks INTERNET DRAFT Nortel Networks
February 8, 2000 Bryan Hill February 21, 2000 Bryan Hill
Expires August 8, 2000 Gotham Networks Expires August 21, 2000 Gotham Networks
<draft-ietf-megaco-protocol-06.txt> Nancy Greene <draft-ietf-megaco-protocol-07.txt> Nancy Greene
Nortel Networks Nortel Networks
Christian Huitema Christian Huitema
Telcordia Technologies Telcordia Technologies
Abdallah Rayhan Abdallah Rayhan
Nortel Networks Nortel Networks
Brian Rosen Brian Rosen
Marconi Marconi
John Segers John Segers
Lucent Technologies Lucent Technologies
skipping to change at page 1, line 40 skipping to change at page 1, line 40
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet- Drafts as reference material time. It is inappropriate to use Internet- Drafts as reference material
or to cite them other than as "work in progress." or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This document will expire in August 2000. This document will expire in July 2000.
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
1. SCOPE ..................................................... 7 1. SCOPE ..................................................... 8
2. REFERENCES ................................................ 7 2. REFERENCES ................................................ 8
2.1. Normative references ................................. 7 2.1. Normative references ................................. 8
2.2. Informative references ............................... 8 2.2. Informative references ............................... 10
3. DEFINITIONS ............................................... 9 3. DEFINITIONS ............................................... 11
4. ABBREVIATIONS ............................................. 10 4. ABBREVIATIONS ............................................. 12
5. CONVENTIONS ............................................... 10 5. CONVENTIONS ............................................... 12
6. CONNECTION MODEL .......................................... 10 6. CONNECTION MODEL .......................................... 12
6.1. Contexts ............................................. 14 6.1. Contexts ............................................. 15
6.1.1. Context Attributes and Descriptors .............. 15 6.1.1. Context Attributes and Descriptors .............. 16
6.1.2. Creating, Deleting and Modifying Contexts ....... 15 6.1.2. Creating, Deleting and Modifying Contexts ....... 16
6.2. Terminations ......................................... 15 6.2. Terminations ......................................... 16
6.2.1. Termination Dynamics ............................ 16 6.2.1. Termination Dynamics ............................ 17
6.2.2. TerminationIDs .................................. 16 6.2.2. TerminationIDs .................................. 17
6.2.3. Packages ........................................ 17 6.2.3. Packages ........................................ 18
6.2.4. Termination Properties and Descriptors .......... 17 6.2.4. Termination Properties and Descriptors .......... 18
6.2.5. Root Termination ................................ 19 6.2.5. Root Termination ................................ 20
7. COMMANDS .................................................. 20 7. COMMANDS .................................................. 21
7.1. Descriptors .......................................... 21 7.1. Descriptors .......................................... 22
7.1.1. Specifying Parameters ........................... 21 7.1.1. Specifying Parameters ........................... 22
7.1.2. Modem Descriptor ................................ 22 7.1.2. Modem Descriptor ................................ 23
7.1.3. Multiplex Descriptor ............................ 22 7.1.3. Multiplex Descriptor ............................ 23
7.1.4. Media Descriptor ................................ 22 7.1.4. Media Descriptor ................................ 23
7.1.5. Termination State Descriptor .................... 23 7.1.5. Termination State Descriptor .................... 24
7.1.6. Stream Descriptor ............................... 24 7.1.6. Stream Descriptor ............................... 24
7.1.7. LocalControl Descriptor ......................... 24 7.1.7. LocalControl Descriptor ......................... 25
7.1.8. Local and Remote Descriptors .................... 25 7.1.8. Local and Remote Descriptors .................... 26
7.1.9. Events Descriptor ............................... 28 7.1.9. Events Descriptor ............................... 29
7.1.10. EventBuffer Descriptor ......................... 29 7.1.10. EventBuffer Descriptor ......................... 31
7.1.11. Signals Descriptor ............................. 29 7.1.11. Signals Descriptor ............................. 31
7.1.12. Audit Descriptor ............................... 31 7.1.12. Audit Descriptor ............................... 33
7.1.13. ServiceChange Descriptor ....................... 32 7.1.13. ServiceChange Descriptor ....................... 34
7.1.14. DigitMap Descriptor ............................ 32 7.1.14. DigitMap Descriptor ............................ 34
7.1.15. Statistics Descriptor .......................... 35 7.1.15. Statistics Descriptor .......................... 39
7.1.16. Packages Descriptor ............................ 36 7.1.16. Packages Descriptor ............................ 39
7.1.17. ObservedEvents Descriptor ...................... 36 7.1.17. ObservedEvents Descriptor ...................... 39
7.1.18. Topology Descriptor ............................ 36 7.1.18. Topology Descriptor ............................ 39
7.2. Command Application Programming Interface ............ 39 7.2. Command Application Programming Interface ............ 42
7.2.1. Add ............................................. 39 7.2.1. Add ............................................. 42
7.2.2. Modify .......................................... 41 7.2.2. Modify .......................................... 44
7.2.3. Subtract ........................................ 42 7.2.3. Subtract ........................................ 44
7.2.4. Move ............................................ 43 7.2.4. Move ............................................ 45
7.2.5. AuditValue ...................................... 44 7.2.5. AuditValue ...................................... 46
7.2.6. AuditCapabilities ............................... 45 7.2.6. AuditCapabilities ............................... 48
7.2.7. Notify .......................................... 46 7.2.7. Notify .......................................... 49
7.2.8. ServiceChange ................................... 46 7.2.8. ServiceChange ................................... 49
7.2.9. Manipulating and Auditing Context Attributes .... 50 7.2.9. Manipulating and Auditing Context Attributes .... 53
7.2.10. Generic Command Syntax ......................... 51 7.2.10. Generic Command Syntax ......................... 54
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
7.3. Command Error Codes .................................. 51 7.3. Command Error Codes .................................. 54
8. TRANSACTIONS .............................................. 53 8. TRANSACTIONS .............................................. 56
8.1. Common Parameters .................................... 54 8.1. Common Parameters .................................... 57
8.1.1. Transaction Identifiers ......................... 54 8.1.1. Transaction Identifiers ......................... 57
8.1.2. Context Identifiers ............................. 55 8.1.2. Context Identifiers ............................. 57
8.2. Transaction Application Programming Interface ........ 55 8.2. Transaction Application Programming Interface ........ 58
8.2.1. TransactionRequest .............................. 55 8.2.1. TransactionRequest .............................. 58
8.2.2. TransactionReply ................................ 56 8.2.2. TransactionReply ................................ 58
8.2.3. TransactionPending .............................. 57 8.2.3. TransactionPending .............................. 59
8.3. Messages ............................................. 57 8.3. Messages ............................................. 60
9. TRANSPORT ................................................. 58 9. TRANSPORT ................................................. 60
9.1. Ordering of Commands ................................. 58 9.1. Ordering of Commands ................................. 61
9.2. Protection against Restart Avalanche ................. 59 9.2. Protection against Restart Avalanche ................. 62
10. SECURITY CONSIDERATIONS .................................. 60 10. SECURITY CONSIDERATIONS .................................. 63
10.1. Protection of Protocol Connections .................. 60 10.1. Protection of Protocol Connections .................. 63
10.2. Interim AH scheme ................................... 61 10.2. Interim AH scheme ................................... 64
10.3. Protection of Media Connections ..................... 62 10.3. Protection of Media Connections ..................... 65
11. MG-MGC CONTROL INTERFACE ................................. 63 11. MG-MGC CONTROL INTERFACE ................................. 65
11.1. Multiple Virtual MGs ................................ 63 11.1. Multiple Virtual MGs ................................ 66
11.2. Cold Start .......................................... 64 11.2. Cold Start .......................................... 67
11.3. Negotiation of Protocol Version ..................... 64 11.3. Negotiation of Protocol Version ..................... 67
11.4. Failure of an MG .................................... 65 11.4. Failure of an MG .................................... 68
11.5. Failure of an MGC ................................... 65 11.5. Failure of an MGC ................................... 68
12. PACKAGE DEFINITION ....................................... 66 12. PACKAGE DEFINITION ....................................... 69
12.1. Guidelines for defining packages .................... 66 12.1. Guidelines for defining packages .................... 70
12.1.1. Package Overall description of the package, .... 67 12.1.1. Package ........................................ 70
12.1.2. Properties ..................................... 67 12.1.2. Properties ..................................... 71
12.1.3. Events ......................................... 68 12.1.3. Events ......................................... 71
12.1.4. Signals ........................................ 68 12.1.4. Signals ........................................ 72
12.1.5. Statistics ..................................... 69 12.1.5. Statistics ..................................... 72
12.1.6. Procedures ..................................... 69 12.1.6. Procedures ..................................... 72
12.2. Guidelines to defining Properties, Statistics and ... 69 12.2. Guidelines to defining Properties, Statistics and .. 72
12.3. Lists ............................................... 69 12.3. Lists ............................................... 73
12.4. Identifiers ......................................... 69 12.4. Identifiers ......................................... 73
12.5. Package Registration ................................ 70 12.5. Package Registration ................................ 73
13. IANA CONSIDERATIONS ...................................... 70 13. IANA CONSIDERATIONS ...................................... 73
13.1. Packages ............................................ 70 13.1. Packages ............................................ 73
13.2. Error Codes ......................................... 70 13.2. Error Codes ......................................... 74
13.3. ServiceChange Reasons ............................... 71 13.3. ServiceChange Reasons ............................... 74
14. CONTACT INFORMATION ...................................... 71 ANNEX A BINARY ENCODING OF THE PROTOCOL (NORMATIVE) ........... 76
ANNEX A BINARY ENCODING OF THE PROTOCOL (NORMATIVE) ........... 73 A.1. Coding of wildcards .................................. 76
A.1. Coding of wildcards .................................. 73 A.2. ASN.1 syntax specification ........................... 78
A.2. ASN.1 syntax specification ........................... 74 A.3. Digit maps and path names ............................ 93
A.3. Digit maps and path names ............................ 89 ANNEX B TEXT ENCODING OF THE PROTOCOL (NORMATIVE) ............. 94
ANNEX B TEXT ENCODING OF THE PROTOCOL (NORMATIVE) ............. 90 B.1. Coding of wildcards .................................. 95
B.1. Coding of wildcards .................................. 90 B.2. ABNF specification ................................... 95
B.2. ABNF specification ................................... 90 ANNEX C TAGS FOR MEDIA STREAM PROPERTIES (NORMATIVE) ..........106
ANNEX C TAGS FOR MEDIA STREAM PROPERTIES (NORMATIVE) ..........101
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
C.1. General Media Attributes .............................102 C.1. General Media Attributes .............................107
C.2. Mux Properties .......................................102 C.2. Mux Properties .......................................107
C.3. General bearer properties ............................102 C.3. General Bearer Properties ............................107
C.4. General ATM properties ...............................103 C.4. General ATM Properties ...............................108
C.5. Frame Relay ..........................................104 C.5. Frame Relay ..........................................108
C.6. IP ...................................................104 C.6. IP ...................................................109
C.7. ATM AAL2 .............................................104 C.7. ATM AAL2 .............................................109
C.8. ATM AAL1 .............................................104 C.8. ATM AAL1 .............................................109
C.9. Bearer Capabilities ..................................105 C.9. Bearer Capabilities ..................................110
C.10. AAL5 Properties .....................................106 C.10. AAL5 Properties .....................................111
C.11. SDP Equivalents .....................................107 C.11. SDP Equivalents .....................................112
C.12. H.245 ...............................................107 C.12. H.245 ...............................................112
ANNEX D TRANSPORT OVER IP (NORMATIVE) .........................107 ANNEX D TRANSPORT OVER IP (NORMATIVE) .........................112
D.1. Transport over IP/UDP using Application Level ........107 D.1. Transport over IP/UDP using Application Level ........112
D.1.1. Providing At-Most-Once Functionality ............107 D.1.1. Providing At-Most-Once Functionality ............113
D.1.2. Transaction identifiers and three-way handshake 108 D.1.2. Transaction identifiers and three-way handshake 113
D.1.3. Computing retransmission timers .................110 D.1.2.1. Transaction identifiers ....................113
D.1.4. Provisional responses ...........................111 D.1.2.2. Three-way handshake ........................114
D.1.5. Repeating Requests, Responses and ...............111 D.1.3. Computing retransmission timers .................114
D.2. Using TCP ............................................112 D.1.4. Provisional responses ...........................115
D.2.1. Providing the At-Most-Once functionality ........113 D.1.5. Repeating Requests, Responses and ...............116
D.2.2. Transaction identifiers and three way handshake 113 D.2. using TCP ............................................117
D.2.3. Computing retransmission timers .................113 D.2.1. Providing the At-Most-Once functionality ........117
D.2.4. Provisional responses ...........................113 D.2.2. Transaction identifiers and three way handshake 118
D.2.5. Ordering of commands ............................114 D.2.3. Computing retransmission timers .................118
ANNEX E BASIC PACKAGES ........................................114 D.2.4. Provisional responses ...........................118
E.1. Generic ..............................................114 D.2.5. Ordering of commands ............................118
E.1.1. Properties ......................................114 ANNEX E BASIC PACKAGES ........................................118
E.1.2. Events ..........................................114 E.1. Generic ..............................................118
E.2.2. Events ..........................................118 E.1.1. Properties ......................................119
E.2.3. Signals .........................................118 E.1.2. Events ..........................................119
E.2.4. Statistics ......................................118 E.3.1. Properties ......................................122
E.2.5. Procedures ......................................118 E.3.2. Events ..........................................123
E.3. Tone Generator Package ...............................118 E.3.3. Signals .........................................123
E.3.1. Properties ......................................118 E.3.4. Statistics ......................................123
E.3.2. Events ..........................................118 E.3.5. Procedures ......................................123
E.3.3. Signals .........................................118 E.4. Tone Detection Package ...............................123
E.3.4. Statistics ......................................119 E.4.1. Properties ......................................124
E.3.5. Procedures ......................................119 E.4.2. Events ..........................................124
E.4. Tone Detection Package ...............................119 E.4.3. Signals .........................................125
E.4.1. Properties ......................................119 E.4.4. Statistics ......................................125
E.4.2. Events ..........................................119 E.4.5. Procedures ......................................125
E.4.3. Signals .........................................121 E.5. Basic DTMF Generator Package .........................125
E.4.4. Statistics ......................................121 E.5.1. Properties ......................................126
E.4.5. Procedures ......................................121 E.5.2. Events ..........................................126
E.5. Basic DTMF Generator Package .........................121
E.5.1. Properties ......................................121
E.5.2. Events ..........................................121
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
E.5.3. Signals .........................................122 E.5.3. Signals .........................................126
E.5.4. Statistics ......................................122 E.5.4. Statistics ......................................127
E.5.5. Procedures ......................................122 E.5.5. Procedures ......................................127
E.6. DTMF detection Package ...............................123 E.6. DTMF detection Package ...............................127
E.6.1. Properties ......................................123 E.6.1. Properties ......................................128
E.6.2. Events ..........................................123 E.6.2. Events ..........................................128
E.6.3. Signals .........................................125 E.6.3. Signals .........................................128
E.6.4. Statistics ......................................125 E.6.4. Statistics ......................................129
E.6.5. Procedures ......................................125 E.6.5. Procedures ......................................129
E.7. Call Progress Tones Generator Package ................125 E.7. Call Progress Tones Generator Package ................129
E.7.1. Properties ......................................125 E.7.1. Properties ......................................129
E.7.2. Events ..........................................125 E.7.2. Events ..........................................129
E.7.3. Signals .........................................125 E.7.3. Signals .........................................129
E.7.4. Statistics ......................................126 E.7.4. Statistics ......................................130
E.7.5. Procedures ......................................126 E.7.5. Procedures ......................................130
E.8. Call Progress Tones Detection Package ................126 E.8. Call Progress Tones Detection Package ................130
E.8.1. Properties ......................................126 E.8.1. Properties ......................................130
E.8.2. Events ..........................................126 E.8.2. Events ..........................................130
E.8.3. Signals .........................................127 E.8.3. Signals .........................................130
E.8.4. Statistics ......................................127 E.8.4. Statistics ......................................131
E.8.5. Procedures ......................................127 E.8.5. Procedures ......................................131
E.9. Analog Line Supervision Package ......................127 E.9. Analog Line Supervision Package ......................131
E.9.1. Properties ......................................127 E.9.1. Properties ......................................131
E.9.2. Events ..........................................127 E.9.2. Events ..........................................131
E.9.3. Signals .........................................128 E.9.3. Signals .........................................132
E.9.4. Statistics ......................................129 E.9.4. Statistics ......................................132
E.9.5. Procedures ......................................129 E.9.5. Procedures ......................................132
E.10. Basic Continuity Package ............................129 E.10. Basic Continuity Package ............................132
E.10.1. Properties .....................................129 E.10.1. Properties .....................................133
E.10.2. Events .........................................129 E.10.2. Events .........................................133
E.10.3. Signals ........................................129 E.10.3. Signals ........................................133
E.10.4. Statistics .....................................130 E.10.4. Statistics .....................................133
E.10.5. Procedures .....................................130 E.10.5. Procedures .....................................134
E.11. Network Package .....................................130 E.11. Network Package .....................................134
E.11.1. Properties .....................................131 E.11.1. Properties .....................................134
E.11.2. Events .........................................131 E.11.2. Events .........................................134
E.11.3. Signals ........................................132 E.11.3. Signals ........................................135
E.11.4. Statistics .....................................132 E.11.4. Statistics .....................................135
E.11.5. Procedures .....................................132 E.11.5. Procedures .....................................136
E.12. RTP Package .........................................132 E.12. RTP Package .........................................136
E.12.1. Properties .....................................133 E.12.1. Properties .....................................136
E.12.2. Events .........................................133 E.12.2. Events .........................................136
E.12.3. Signals ........................................133 E.12.3. Signals ........................................137
E.12.4. Statistics .....................................133 E.12.4. Statistics .....................................137
E.12.5. Procedures .....................................134 E.12.5. Procedures .....................................137
E.13. DS0 Package ........................................134 E.13. TDM Circuit Package ................................137
E.13.1. Properties .....................................134 E.13.1. Properties .....................................138
E.13.2. Events .........................................135 E.13.2. Events .........................................138
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
E.13.3. Signals ........................................131 E.13.3. Signals ........................................138
E.13.4. Statistics .....................................131 E.13.4. Statistics .....................................138
E.13.5. Procedures .....................................132 E.13.5. Procedures .....................................138
APPENDIX A EXAMPLE CALL FLOWS (INFORMATIVE) ..............132 APPENDIX A EXAMPLE CALL FLOWS (INFORMATIVE) ..............139
A.1. Residential Gateway to Residential Gateway Call ......132 A.1. Residential Gateway to Residential Gateway Call .....139
A.1.1. Programming Residential GW Analog Line ..........132 A.1.1. Programming Residential GW Analog Line .........139
A.1.2. Collecting Originator Digits ....................141
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
TABLE OF FIGURES TABLE OF FIGURES
Figure 1: Example of MEGACOH.248 Connection Model ...............12 Figure 1 Example of MEGACOH.248 Connection Model................13
Figure 3: Example Call Waiting Scenario / Alerting Applied to T1 13 Figure 2 Example Call Waiting Scenario / Alerting Applied to T1.14
Figure 4: Example Call Waiting Scenario / Answer by T1 ..........14 Figure 3 Example Call Waiting Scenario / Answer by T1...........15
Figure 5: Example topologies ...................................38 Figure 4 Example topologies......................... ...........41
Figure 6: Transactions, Actions and Commands.....................53 Figure 5 Transactions, Actions and Commands.....................56
Internet draft MEGACO Protocol February 21, 2000
1. SCOPE 1. SCOPE
MEGACO defines the protocols used between elements of a physically MEGACO defines the protocols used between elements of a physically
decomposed multimedia Gateway consisting of a Media Gateway and a Media decomposed multimedia gateway. There are no functional differences from
Gateway Controller. There are no functional differences from a system a system view between a decomposed gateway, with distributed sub-
view between a decomposed gateway, with distributed sub- components components potentially on more than one physical device, and a monol-
potentially on more than one physical device, and a monolithic gateway. ithic gateway such as described in H.246. This document does not define
This document does not define how gateways, multipoint control units or how gateways, multipoint control units or integrated voice response
integrated voice response units (IVRs) work. Instead it creates a gen- units (IVRs) work. Instead it creates a general framework that is suit-
eral framework that is suitable for these applications. able for these applications.
Packet network interfaces may include IP, ATM or possibly others. The Packet network interfaces may include IP, ATM or possibly others. The
interfaces will support a variety of SCN signalling systems, including interfaces will support a variety of SCN signalling systems, including
tone signalling, ISDN, ISUP, QSIG, and GSM. National variants of these tone signalling, ISDN, ISUP, QSIG, and GSM. National variants of these
signalling systems will be supported where applicable. signalling systems will be supported where applicable.
The protocol definition in this document is common text with ITU Recom- The protocol definition in this document is common text with ITU Recom-
mendation H.248. mendation H.248.
2. REFERENCES 2. REFERENCES
skipping to change at page 8, line 5 skipping to change at page 8, line 46
ITU-T Recommendation H.245 (1998): "Control Protocol for Multimedia Com- ITU-T Recommendation H.245 (1998): "Control Protocol for Multimedia Com-
munication". munication".
ITU-T Recommendation H.323 (1998): "Packet Based Multimedia Communica- ITU-T Recommendation H.323 (1998): "Packet Based Multimedia Communica-
tion Systems". tion Systems".
ITU-T Recommendation I.363.1 (08/96), "B-ISDN ATM Adaptation Layer ITU-T Recommendation I.363.1 (08/96), "B-ISDN ATM Adaptation Layer
specification: Type 1 AAL". specification: Type 1 AAL".
Internet draft MEGACO Protocol February 8, 2000 ITU-T Recommendation I.363.2 (09/97), "B-ISDN ATM Adaptation Layer
specification: Type 2 AAL".
ITU-T Recommendation I.366.1 (06/98), "Segmentation and Reassembly Ser- ITU-T Recommendation I.366.1 (06/98), "Segmentation and Reassembly Ser-
vice Specific Convergence Sublayer for the AAL type 2". vice Specific Convergence Sublayer for the AAL type 2".
ITU-T Recommendation I.366.2 (02/99), "AAL type 2 service specific con- ITU-T Recommendation I.366.2 (02/99), "AAL type 2 service specific con-
vergence sublayer for trunking". vergence sublayer for trunking".
Internet draft MEGACO Protocol February 21, 2000
ITU-T Recommendation I.371 (08/96), "Traffic control and congestion con-
trol in B- ISDN".
ITU-T Recommendation Q.763 (09/97), "Signalling System No. 7 - ISDN user
part formats and codes".
ITU-T Recommendation Q.765, "Signalling System No. 7 - Application tran-
sport mechanism".
ITU-T Recommendation Q.931 (05/98): "Digital Subscriber Signalling Sys- ITU-T Recommendation Q.931 (05/98): "Digital Subscriber Signalling Sys-
tem No. 1 (DSS 1) - ISDN User-Network Interface Layer 3 Specification tem No. 1 (DSS 1) - ISDN User-Network Interface Layer 3 Specification
for Basic Call Control" for Basic Call Control".
ITU-T Recommendation Q.2630.1 (1999), "AAL Type 2 Signalling Protocol
(Capability Set 1)".
ITU-T Recommendation Q.2931 (10/95), "Broadband Integrated Services
Digital Network (B-ISDN) - Digital Subscriber Signalling System No. 2
(DSS 2) - User- Network Interface (UNI) - Layer 3 specification for
basic call/connection control".
ITU-T Recommendation Q.2941.1 (09/97), "Digital Subscriber Signalling
System No. 2 - Generic Identifier Transport".
ITU-T Recommendation Q.2961 (10/95), "Broadband integrated services
digital network (B-ISDN) - Digital subscriber signalling system no.2
(DSS 2) - additional traffic parameters".
ITU-T Recommendation Q.2961.2 (06/97), "Digital subscriber signalling
system No. 2 - Additional traffic parameters: Support of ATM transfer
capability in the broadband bearer capability information element."
ITU-T Recommendation X.213 (11/1995), "Information technology - Open
System Interconnection - Network service definition plus Amendment 1
(08/1997), Addition of the Internet protocol address format identifier".
ITU-T Recommendation V.76 (08/96), "Generic multiplexer using V.42
LAPM-based procedures".
ITU-T Recommendation X.680 (1997): "Information technology-Abstract Syn- ITU-T Recommendation X.680 (1997): "Information technology-Abstract Syn-
tax Notation One (ASN.1): Specification of basic notation". tax Notation One (ASN.1): Specification of basic notation".
ITU-T draft Recommendation H.246 (1998), "Interworking of H-series mul- ITU-T Recommendation H.246 (1998), "Interworking of H-series multimedia
timedia terminals with H-series multimedia terminals and voice/voiceband terminals with H-series multimedia terminals and voice/voiceband termi-
terminals on GSTN and ISDN". nals on GSTN and ISDN".
RFC 1006, "ISO Transport Service on top of the TCP, Version 3", Marshall RFC 1006, "ISO Transport Service on top of the TCP, Version 3", Marshall
T. Rose, Dwight E. Cass, May 1987. T. Rose, Dwight E. Cass, May 1987.
RFC 2119, "Key words for use in RFCs to Indicate Requirement Levels", Internet draft MEGACO Protocol February 21, 2000
Scott Bradner, March 1997. RFC 2234, "Augmented BNF for Syntax Specifi-
cations: ABNF", D. Crocker, P. Overell, November 1997. RFC 2234, "Augmented BNF for Syntax Specifications: ABNF", D. Crocker,
P. Overell, November 1997.
RFC 2327, "SDP: Session Description Protocol", M. Handley, V. Jacobson, RFC 2327, "SDP: Session Description Protocol", M. Handley, V. Jacobson,
April 1998. April 1998.
RFC 2402, "IP Authentication Header", S. Kent, R. Atkinson, November RFC 2402, "IP Authentication Header", S. Kent, R. Atkinson, November
1998. 1998.
RFC 2406, "IP Encapsulating Security Payload (ESP)", S. Kent, R. Atkin- RFC 2406, "IP Encapsulating Security Payload (ESP)", S. Kent, R. Atkin-
son, November 1998. son, November 1998.
2.2. Informative references 2.2. Informative references
ITU-T Recommendation E.180/Q.35 (1998): "Technical characteristics of ITU-T Recommendation E.180/Q.35 (1998): "Technical characteristics of
tones for the telephone service" tones for the telephone service".
ITU-T Recommendation Q.724 (1988): "Signalling procedures" CCITT Recommendation G.711 (1988), "Pulse Code Modulation (PCM) of voice
frequencies".
ITU-T Recommendation H.221 (05/99),"Frame structure for a 64 to 1920
kbit/s channel in audiovisual teleservices".
ITU-T Recommendation H.223 (1996), "Multiplexing protocol for low bit
rate multimedia communication".
ITU-T Recommendation Q.724 (1988): "Signalling procedures".
RFC 768, "User Datagram Protocol", J.Postel, August 1980. RFC 768, "User Datagram Protocol", J.Postel, August 1980.
RFC 791, "Internet protocol", J.Postel, September 1981.
RFC 793, "TRANSMISSION CONTROL PROTOCOL", J.Postel, September 1981. RFC 793, "TRANSMISSION CONTROL PROTOCOL", J.Postel, September 1981.
RFC 1889, "RTP: A Transport Protocol for Real-Time Applications", H. RFC 1889, "RTP: A Transport Protocol for Real-Time Applications", H.
Schulzrinne, S. Casner, R. Frederick, V. Jacobson, January 1996. Schulzrinne, S. Casner, R. Frederick, V. Jacobson, January 1996.
RFC 1890, "RTP Profile for Audio and Video Conferences with Minimal RFC 1890, "RTP Profile for Audio and Video Conferences with Minimal Con-
trol", H. Schulzrinne, January 1996.
Internet draft MEGACO Protocol February 8, 2000
Control", H. Schulzrinne, January 1996.
RFC 2401, "Security Architecture for the Internet Protocol", S. Kent, R. RFC 2401, "Security Architecture for the Internet Protocol", S. Kent, R.
Atkinson, November 1998. Atkinson, November 1998.
RFC 2543, " SIP: Session Initiation Protocol", M. Handley, H. RFC 2543, " SIP: Session Initiation Protocol", M. Handley, H.
Schulzrinne, E. Schooler, J. Rosenberg, March 1999. Schulzrinne, E. Schooler, J. Rosenberg, March 1999.
RFC 2460, "Internet Protocol, Version 6 (IPv6) Specification", S. Deer- RFC 2460, "Internet Protocol, Version 6 (IPv6) Specification", S. Deer-
ing, R. Hinden, December 1998. ing, R. Hinden, December 1998.
Internet draft MEGACO Protocol February 21, 2000
3. DEFINITIONS 3. DEFINITIONS
Access Gateway: A type of gateway that provides a User to Network Inter- Access Gateway: A type of gateway that provides a User to Network Inter-
face (UNI) such as ISDN. face (UNI) such as ISDN.
Descriptor: A syntactic element of the protocol that groups related pro- Descriptor: A syntactic element of the protocol that groups related pro-
perties. For instance, the properties of a media flow on the MG can be perties. For instance, the properties of a media flow on the MG can be
set by the MGC by including the appropriate descriptor in a command. set by the MGC by including the appropriate descriptor in a command.
Media Gateway (MG): The media gateway converts media provided in one Media Gateway (MG): The media gateway converts media provided in one
type of network to the format required in another type of network. For type of network to the format required in another type of network. For
example, a MG could terminate bearer channels from a switched circuit example, a MG could terminate bearer channels from a switched circuit
network (i.e., DS0s) and media streams from a packet network (e.g., RTP network (e.g., DS0s) and media streams from a packet network (e.g., RTP
streams in an IP network). This gateway may be capable of processing streams in an IP network). This gateway may be capable of processing
audio, video and T.120 alone or in any combination, and will be capable audio, video and T.120 alone or in any combination, and will be capable
of full duplex media translations. The MG may also play audio/video mes- of full duplex media translations. The MG may also play audio/video mes-
sages and performs other IVR functions, or may perform media conferenc- sages and performs other IVR functions, or may perform media conferenc-
ing. ing.
Media Gateway Controller (MGC): Controls the parts of the call state Media Gateway Controller (MGC): Controls the parts of the call state
that pertain to connection control for media channels in a MG. that pertain to connection control for media channels in a MG.
Multipoint Control Unit (MCU): An entity that controls the setup and Multipoint Control Unit (MCU): An entity that controls the setup and
skipping to change at page 10, line 4 skipping to change at page 11, line 44
packet network. A residential gateway typically contains one or two packet network. A residential gateway typically contains one or two
analogue lines and is located at the customer premises. analogue lines and is located at the customer premises.
SCN FAS Signalling Gateway: This function contains the SCN Signalling SCN FAS Signalling Gateway: This function contains the SCN Signalling
Interface that terminates SS7, ISDN or other signalling links where the Interface that terminates SS7, ISDN or other signalling links where the
call control channel and bearer channels are collocated in the same phy- call control channel and bearer channels are collocated in the same phy-
sical span. sical span.
SCN NFAS Signalling Gateway: This function contains the SCN Signalling SCN NFAS Signalling Gateway: This function contains the SCN Signalling
Interface that terminates SS7 or other signalling links where the call Interface that terminates SS7 or other signalling links where the call
Internet draft MEGACO Protocol February 8, 2000
control channels are separated from bearer channels. control channels are separated from bearer channels.
Stream: Bidirectional media or control flow received/sent by a media Stream: Bidirectional media or control flow received/sent by a media
gateway as part of a call or conference. gateway as part of a call or conference.
Trunk: A communication channel between two switching systems such as a Trunk: A communication channel between two switching systems such as a
DS0 on a T1 or E1 line. DS0 on a T1 or E1 line.
Trunking Gateway: A gateway between SCN network and packet network that Trunking Gateway: A gateway between SCN network and packet network that
typically terminates a large number of digital circuits. typically terminates a large number of digital circuits.
Internet draft MEGACO Protocol February 21, 2000
4. ABBREVIATIONS 4. ABBREVIATIONS
This recommendation defines the following terms. This recommendation defines the following terms.
ATM Asynchronous Transfer Mode ATM Asynchronous Transfer Mode
BRI Basic Rate Interface BRI Basic Rate Interface
CAS Channel Associated Signalling CAS Channel Associated Signalling
DTMF Dual Tone Multi-Frequency DTMF Dual Tone Multi-Frequency
FAS Facility Associated Signalling FAS Facility Associated Signalling
GW GateWay GW GateWay
IANA Internet Assigned Numbers Authority
IP Internet Protocol IP Internet Protocol
ISUP ISDN User Part ISUP ISDN User Part
MG Media Gateway MG Media Gateway
MGC Media Gateway Controller MGC Media Gateway Controller
NFAS Non-Facility Associated Signalling NFAS Non-Facility Associated Signalling
PRI Primary Rate Interface PRI Primary Rate Interface
PSTN Public Switched Telephone Network PSTN Public Switched Telephone Network
QoS Quality of Service QoS Quality of Service
RTP Real-time Transport Protocol RTP Real-time Transport Protocol
SCN Switched Circuit Network SCN Switched Circuit Network
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document are to be interpreted as described in RFC2119. document are to be interpreted as described in RFC2119.
6. CONNECTION MODEL 6. CONNECTION MODEL
The connection model for the protocol describes the logical entities, or The connection model for the protocol describes the logical entities, or
objects, within the Media Gateway that can be controlled by the Media objects, within the Media Gateway that can be controlled by the Media
Gateway Controller. The main abstractions used in the connection model Gateway Controller. The main abstractions used in the connection model
are Terminations and Contexts. are Terminations and Contexts.
A Termination sources and/or sinks one or more streams. In a multimedia A Termination sources and/or sinks one or more streams. In a multimedia
conference, a Termination can be multimedia and sources or sinks conference, a Termination can be multimedia and sources or sinks multi-
ple media streams. The media stream parameters, as well as modem, and
Internet draft MEGACO Protocol February 8, 2000 bearer parameters are encapsulated within the Termination.
multiple media streams. The media stream parameters, as well as modem,
and bearer parameters are encapsulated within the Termination.
A Context is an association between a collection of Terminations. There A Context is an association between a collection of Terminations. There
is a special type of Context, the null Context, which contains all Ter- is a special type of Context, the null Context, which contains all Ter-
minations that are not associated to any other Termination. For minations that are not associated to any other Termination. For
instance, in a decomposed access gateway, all idle lines are represented instance, in a decomposed access gateway, all idle lines are represented
by Terminations in the null Context. by Terminations in the null Context.
Following is a graphical depiction of these concepts. The diagram of Following is a graphical depiction of these concepts. The diagram of
Internet draft MEGACO Protocol February 21, 2000
Figure 1 gives several examples and is not meant to be an all-inclusive Figure 1 gives several examples and is not meant to be an all-inclusive
illustration. The asterisk box in each of the Contexts represents the illustration. The asterisk box in each of the Contexts represents the
logical association of Terminations implied by the Context. logical association of Terminations implied by the Context.
Internet draft MEGACO Protocol February 8, 2000
+------------------------------------------------------+ +------------------------------------------------------+
|Media Gateway | |Media Gateway |
| +-------------------------------------------------+ | | +-------------------------------------------------+ |
| |Context +-------------+ | | | |Context +-------------+ | |
| | | Termination | | | | | | Termination | | |
| | |-------------| | | | | |-------------| | |
| | +-------------+ +->| SCN Bearer |<---+-> | | +-------------+ +->| SCN Bearer |<---+->
| | | Termination | +-----+ | | Channel | | | | | | Termination | +-----+ | | Channel | | |
| | |-------------| | |---+ +-------------+ | | | | |-------------| | |---+ +-------------+ | |
<-+--->| RTP Stream |---| * | | | <-+--->| RTP Stream |---| * | | |
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| | | Termination | +-----+ | Termination | | | | | | Termination | +-----+ | Termination | | |
| | |-------------| | | |-------------| | | | | |-------------| | | |-------------| | |
<-+--->| SCN Bearer |---| * |------| SCN Bearer |<---+-> <-+--->| SCN Bearer |---| * |------| SCN Bearer |<---+->
| | | Channel | | | | Channel | | | | | | Channel | | | | Channel | | |
| | +-------------+ +-----+ +-------------+ | | | | +-------------+ +-----+ +-------------+ | |
| +-------------------------------------------------+ | | +-------------------------------------------------+ |
| ___________________________________________________ | | ___________________________________________________ |
+------------------------------------------------------+ +------------------------------------------------------+
Figure 1: Example of MEGACO Connection Model Figure 1: Example of MEGACO Connection Model
Internet draft MEGACO Protocol February 21, 2000
The example below shows an example of one way to accomplish a call- The example below shows an example of one way to accomplish a call-
waiting scenario in a decomposed access gateway, illustrating the relo- waiting scenario in a decomposed access gateway, illustrating the relo-
cation of a Termination between Contexts. Terminations T1 and T2 belong cation of a Termination between Contexts. Terminations T1 and T2 belong
to Context C1 in a two-way audio call. A second audio call is waiting to Context C1 in a two-way audio call. A second audio call is waiting
Internet draft MEGACO Protocol February 8, 2000
for T1 from Termination T3. T3 is alone in Context C2. T1 accepts the for T1 from Termination T3. T3 is alone in Context C2. T1 accepts the
call from T3, placing T2 on hold. This action results in T1 moving into call from T3, placing T2 on hold. This action results in T1 moving into
Context C2, as shown below. Context C2, as shown below.
+------------------------------------------------------+ +------------------------------------------------------+
|Media Gateway | |Media Gateway |
| +-------------------------------------------------+ | | +-------------------------------------------------+ |
| |Context C1 | | | |Context C1 | |
| | +-------------+ +-------------+ | | | | +-------------+ +-------------+ | |
| | | Term. T2 | +-----+ | Term. T1 | | | | | | Term. T2 | +-----+ | Term. T1 | | |
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| | +-------------+ | | | | +-------------+ | |
| | +-----+ | Term. T3 | | | | | +-----+ | Term. T3 | | |
| | | | |-------------| | | | | | | |-------------| | |
| | | * |------| SCN Bearer |<---+-> | | | * |------| SCN Bearer |<---+->
| | | | | Channel | | | | | | | | Channel | | |
| | +-----+ +-------------+ | | | | +-----+ +-------------+ | |
| +-------------------------------------------------+ | | +-------------------------------------------------+ |
+------------------------------------------------------+ +------------------------------------------------------+
Figure 2 Example Call Waiting Scenario / Alerting Applied to T1 Figure 2 Example Call Waiting Scenario / Alerting Applied to T1
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
+------------------------------------------------------+ +------------------------------------------------------+
|Media Gateway | |Media Gateway |
| +-------------------------------------------------+ | | +-------------------------------------------------+ |
| |Context C1 | | | |Context C1 | |
| | +-------------+ | | | | +-------------+ | |
| | | Term. T2 | +-----+ | | | | | Term. T2 | +-----+ | |
| | |-------------| | | | | | | |-------------| | | | |
<-+--->| RTP Stream |---| * | | | <-+--->| RTP Stream |---| * | | |
| | | | | | | | | | | | | | | |
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the MGC does not specify an existing Context to which the Termination is the MGC does not specify an existing Context to which the Termination is
to be added, the MG creates a new Context. A Termination may be removed to be added, the MG creates a new Context. A Termination may be removed
from a Context with a Subtract command, and a Termination may be moved from a Context with a Subtract command, and a Termination may be moved
from one Context to another with a Move command. A Termination SHALL from one Context to another with a Move command. A Termination SHALL
exist in only one Context at a time. exist in only one Context at a time.
The maximum number of Terminations in a Context is a MG property. Media The maximum number of Terminations in a Context is a MG property. Media
gateways that offer only point-to-point connectivity might allow at most gateways that offer only point-to-point connectivity might allow at most
two Terminations per Context. Media gateways that support multipoint two Terminations per Context. Media gateways that support multipoint
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
conferences might allow three or more terminations per Context. conferences might allow three or more terminations per Context.
6.1.1. Context Attributes and Descriptors 6.1.1. Context Attributes and Descriptors
The attributes of Contexts are: The attributes of Contexts are:
ContextID, a 32 bit unsigned integer chosen by the MG. The topology * ContextID.
(who hears/sees whom). The topology of a Context describes the flow of
media between the Terminations within a Context. In contrast, the mode
of a Termination (send/receive/...) describes the flow of the media at
the ingress/egress of the media gateway.
The priority is used for a context in order to provide the MG with * The topology (who hears/sees whom). The topology of a Context
information about a certain precedence handling for a context. The MGC describes the flow of media between the Terminations within a Con-
can also use the priority to control autonomously the traffic precedence text. In contrast, the mode of a Termination (send/receive/...)
in the MG in a smooth way in certain situations (e.g. restart), when a describes the flow of the media at the ingress/egress of the media
lot of contexts must be handled simultaneously. gateway.
* The priority is used for a context in order to provide the MG with
information about a certain precedence handling for a context. The
MGC can also use the priority to control autonomously the traffic
precedence in the MG in a smooth way in certain situations (e.g.
restart), when a lot of contexts must be handled simultaneously.
* An indicator for an emergency call is also provided to allow a * An indicator for an emergency call is also provided to allow a
preference handling in the MG. preference handling in the MG.
6.1.2. Creating, Deleting and Modifying Contexts 6.1.2. Creating, Deleting and Modifying Contexts
The protocol can be used to (implicitly) create Contexts and modify the The protocol can be used to (implicitly) create Contexts and modify the
parameter values of existing Contexts. The protocol has commands to add parameter values of existing Contexts. The protocol has commands to add
Terminations to Contexts, subtract them from Contexts, and to move Ter- Terminations to Contexts, subtract them from Contexts, and to move Ter-
minations between Contexts. Contexts are deleted implicitly when the minations between Contexts. Contexts are deleted implicitly when the
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Terminations representing physical entities have a semi-permanent Terminations representing physical entities have a semi-permanent
existence. For example, a Termination representing a TDM channel might existence. For example, a Termination representing a TDM channel might
exist for as long as it is provisioned in the gateway. Terminations exist for as long as it is provisioned in the gateway. Terminations
representing ephemeral information flows, such as RTP flows, would usu- representing ephemeral information flows, such as RTP flows, would usu-
ally exist only for the duration of their use. ally exist only for the duration of their use.
Ephemeral Terminations are created by means of an Add command. They are Ephemeral Terminations are created by means of an Add command. They are
destroyed by means of a Subtract command. In contrast, when a physical destroyed by means of a Subtract command. In contrast, when a physical
Termination is Added to or Subtracted from a Context, it is taken from Termination is Added to or Subtracted from a Context, it is taken from
or to the null Context, respectively.
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
or to the null Context, respectively.
Terminations may have signals applied to them. Signals are MG generated Terminations may have signals applied to them. Signals are MG generated
media streams such as tones and announcements as well as line signals media streams such as tones and announcements as well as line signals
such as hookswitch. Terminations may be programmed to detect Events, such as hookswitch. Terminations may be programmed to detect Events,
the occurrence of which can trigger notification messages to the MGC, or the occurrence of which can trigger notification messages to the MGC, or
action by the MG. Statistics may be accumulated on a Termination. action by the MG. Statistics may be accumulated on a Termination.
Statistics are reported to the MGC upon request (by means of the Audit- Statistics are reported to the MGC upon request (by means of the Audit-
Value command, see section 7.2.5) and when the Termination is taken out Value command, see section 7.2.5) and when the Termination is taken out
of the call it is in. of the call it is in.
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6.2.2. TerminationIDs 6.2.2. TerminationIDs
Terminations are referenced by a TerminationID, which is an arbitrary Terminations are referenced by a TerminationID, which is an arbitrary
schema chosen by the MG. schema chosen by the MG.
TerminationIDs of physical Terminations are provisioned in the Media TerminationIDs of physical Terminations are provisioned in the Media
Gateway. The TerminationIDs may be chosen to have structure. For Gateway. The TerminationIDs may be chosen to have structure. For
instance, a TerminationID may consist of trunk group and a trunk within instance, a TerminationID may consist of trunk group and a trunk within
the group. the group.
A wildcarding mechanism using two types of wildcards can be used with Internet draft MEGACO Protocol February 21, 2000
Internet draft MEGACO Protocol February 8, 2000
A wildcarding mechanism using two types of wildcards can be used with
TerminationIDs. The two wildcards are ALL and CHOOSE. The former is TerminationIDs. The two wildcards are ALL and CHOOSE. The former is
used to address multiple Terminations at once, while the latter is used used to address multiple Terminations at once, while the latter is used
to indicate to a media gateway that it must select a Termination satis- to indicate to a media gateway that it must select a Termination satis-
fying the partially specified TerminationID. This allows, for instance, fying the partially specified TerminationID. This allows, for instance,
that a MGC instructs a MG to choose a circuit within a trunk group. that a MGC instructs a MG to choose a circuit within a trunk group.
When ALL is used in the TerminationID of a command, the effect is ident- When ALL is used in the TerminationID of a command, the effect is ident-
ical to repeating the command with each of the matching TerminationIDs. ical to repeating the command with each of the matching TerminationIDs.
Since each of these commands may generate a response, the size of the Since each of these commands may generate a response, the size of the
entire response may be large. If individual responses are not required, entire response may be large. If individual responses are not required,
a wildcard response may be requested. In such a case, a single response a wildcard response may be requested. In such a case, a single response
is generated, which contains the UNION of all of the individual is generated, which contains the UNION of all of the individual
responses which otherwise would have been generated. Wildcard response responses which otherwise would have been generated, with duplicate
may be particularly useful in the Audit commands. values suppressed. Wildcard response may be particularly useful in the
Audit commands.
The encoding of the wildcarding mechanism is detailed in Annexes A and The encoding of the wildcarding mechanism is detailed in Annexes A and
B. B.
6.2.3. Packages 6.2.3. Packages
Different types of gateways may implement Terminations that have widely Different types of gateways may implement Terminations that have widely
differing characteristics. Variations in Terminations are accommodated differing characteristics. Variations in Terminations are accommodated
in the protocol by allowing Terminations to have optional Properties, in the protocol by allowing Terminations to have optional Properties,
Events, Signals and Statistics implemented by MGs. Events, Signals and Statistics implemented by MGs.
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6.2.4. Termination Properties and Descriptors 6.2.4. Termination Properties and Descriptors
Terminations have properties. The properties have unique PropertyIDs. Terminations have properties. The properties have unique PropertyIDs.
Most properties have default values. When a Termination is created, Most properties have default values. When a Termination is created,
properties get their default values, unless the controller specifically properties get their default values, unless the controller specifically
sets a different value. The default value of a property of a physical sets a different value. The default value of a property of a physical
Termination can be changed by setting it to a different value when the Termination can be changed by setting it to a different value when the
Termination is in the null Context. Every time such a Termination Termination is in the null Context. Every time such a Termination
returns to the null Context, the values of its properties are reset to returns to the null Context, the values of its properties are reset to
this default value.
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
this default value.
There are a number of common properties for Terminations and properties There are a number of common properties for Terminations and properties
specific to media streams. The common properties are also called the specific to media streams. The common properties are also called the
termination state properties. For each media stream, there are local termination state properties. For each media stream, there are local
properties and properties of the received and transmitted flows. properties and properties of the received and transmitted flows.
Properties not included in the base protocol are defined in Packages. Properties not included in the base protocol are defined in Packages.
These properties are referred to by a name consisting of the PackageName These properties are referred to by a name consisting of the PackageName
and a PropertyId. Most properties have default values described in the and a PropertyId. Most properties have default values described in the
Package description. Properties may be read-only or read/write. The pos- Package description. Properties may be read-only or read/write. The pos-
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When a Termination is Added to a Context, the value of its read/write When a Termination is Added to a Context, the value of its read/write
properties can be set by including the appropriate descriptors as param- properties can be set by including the appropriate descriptors as param-
eters to the Add command. Properties not mentioned in the command eters to the Add command. Properties not mentioned in the command
retain their prior values. Similarly, a property of a Termination in a retain their prior values. Similarly, a property of a Termination in a
Context may have its value changed by the Modify command. Properties Context may have its value changed by the Modify command. Properties
not mentioned in the Modify command retain their prior values. Proper- not mentioned in the Modify command retain their prior values. Proper-
ties may also have their values changed when a Termination is moved from ties may also have their values changed when a Termination is moved from
one Context to another as a result of a Move command. In some cases, one Context to another as a result of a Move command. In some cases,
descriptors are returned as output from a command. The following table descriptors are returned as output from a command. The following table
lists all of the possible Descriptors and their use. Not all descrip- lists all of the possible Descriptors and their use. Not all descrip-
tors are legal as input or output parameters to every command. Descrip- tors are legal as input or output parameters to every command.
tors
_________________________________________________________________________
|Descriptor Name |Description | |Descriptor Name |Description |
|__________________|____________________________________________________| |__________________|____________________________________________________|
|Modem |Identifies modem type and properties when | |Modem |Identifies modem type and properties when |
| |applicable | | |applicable |
|__________________|____________________________________________________| |__________________|____________________________________________________|
|Mux |Describes multiplex type for multimedia terminations| |Mux |Describes multiplex type for multimedia terminations|
| |(e.g. H.221, H.223, H.225.0) and Terminations | | |(e.g. H.221, H.223, H.225.0) and Terminations |
| |forming the input mux. | | |forming the input mux. |
|__________________|____________________________________________________| |__________________|____________________________________________________|
|Media |A list of media stream specifications (see 7.1.4) | |Media |A list of media stream specifications (see 7.1.4) |
|__________________|____________________________________________________| |__________________|____________________________________________________|
|TerminationState |Properties of a Termination (which can be defined in| |TerminationState |Properties of a Termination (which can be defined in|
| |Packages) that are not stream specific. | | |Packages) that are not stream specific. |
|__________________|____________________________________________________| |__________________|____________________________________________________|
|Stream |A list of remote/local/localControl descriptors for | |Stream |A list of remote/local/localControl descriptors for |
| |a single stream | |__________________|____________________________________________________| | |a single stream | |__________________|____________________________________________________|
|Local |Contains properties that specify the media flows | |Local |Contains properties that specify the media flows |
Internet draft MEGACO Protocol February 21, 2000
| |that MG receives from the remote entity. | | |that MG receives from the remote entity. |
|__________________|____________________________________________________| |__________________|____________________________________________________|
| | | | | |
Internet draft MEGACO Protocol February 8, 2000
|Remote |Contains properties that specify the media flows | |Remote |Contains properties that specify the media flows |
| |that the MG sends to the remote entity. | |__________________|____________________________________________________| | |that the MG sends to the remote entity. | |__________________|____________________________________________________|
|LocalControl |Contains properties (which can be defined in | |LocalControl |Contains properties (which can be defined in |
| |packages) that are of interest between the MG and | | |packages) that are of interest between the MG and |
| |the MGC | |__________________|____________________________________________________| | |the MGC | |__________________|____________________________________________________|
|Events |Describes events to be detected by the MG and what | |Events |Describes events to be detected by the MG and what |
| |to do when an event is detected | |__________________|____________________________________________________| | |to do when an event is detected | |__________________|____________________________________________________|
|EventBuffer |Describes events to be detected by the MG when Event| |EventBuffer |Describes events to be detected by the MG when Event|
| |Buffering is active | |__________________|____________________________________________________| | |Buffering is active | |__________________|____________________________________________________|
|Signals |Describes signals and/or actions to be applied (e.g.| |Signals |Describes signals and/or actions to be applied (e.g.|
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ingly, the root TerminationID may appear in: ingly, the root TerminationID may appear in:
* a Modify command - to change a property or set an event * a Modify command - to change a property or set an event
* a Notify command - to report an event * a Notify command - to report an event
* an AuditValue return - to examine the values of properties imple- * an AuditValue return - to examine the values of properties imple-
mented on root mented on root
* an AuditCapability - to determine what properties of root are * an AuditCapability - to determine what properties of root are
implemented implemented a ServiceChange - to declare the gateway in or out of
service Any other use of the root TerminationID is an error.
* a ServiceChange - to declare the gateway in or out of service Any
other use of the root TerminationID is an error.
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
7. COMMANDS 7. COMMANDS
The protocol provides commands for manipulating the logical entities of The protocol provides commands for manipulating the logical entities of
the protocol connection model, Contexts and Terminations. Commands pro- the protocol connection model, Contexts and Terminations. Commands pro-
vide control at the finest level of granularity supported by the proto- vide control at the finest level of granularity supported by the proto-
col. For example, Commands exist to add Terminations to a Context, col. For example, Commands exist to add Terminations to a Context,
modify Terminations, subtract Terminations from a Context, and audit modify Terminations, subtract Terminations from a Context, and audit
properties of Contexts or Terminations. Commands provide for complete properties of Contexts or Terminations. Commands provide for complete
control of the properties of Contexts and Terminations. This includes control of the properties of Contexts and Terminations. This includes
skipping to change at page 21, line 5 skipping to change at page 22, line 5
possible values for Termination properties, events and signals possible values for Termination properties, events and signals
allowed by the Media Gateway. allowed by the Media Gateway.
7. Notify. The Notify command allows the Media Gateway to inform the 7. Notify. The Notify command allows the Media Gateway to inform the
Media Gateway Controller of the occurrence of events in the Media Media Gateway Controller of the occurrence of events in the Media
Gateway. Gateway.
8. ServiceChange. The ServiceChange Command allows the Media Gateway 8. ServiceChange. The ServiceChange Command allows the Media Gateway
to notify the Media Gateway Controller that a Termination or group to notify the Media Gateway Controller that a Termination or group
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
of Terminations is about to be taken out of service or has just of Terminations is about to be taken out of service or has just
been returned to service. ServiceChange is also used by the MG to been returned to service. ServiceChange is also used by the MG to
announce its availability to an MGC (registration), and to notify announce its availability to an MGC (registration), and to notify
the MGC of impending or completed restart of the MG. The MGC may the MGC of impending or completed restart of the MG. The MGC may
announce a handover to the MG by sending it a ServiceChange com- announce a handover to the MG by sending it a ServiceChange com-
mand. The MGC may also use ServiceChange to instruct the MG to mand. The MGC may also use ServiceChange to instruct the MG to
take a Termination or group of Terminations in or out of service. take a Termination or group of Terminations in or out of service.
These commands are detailed in sections 7.2.1 through 7.2.8 These commands are detailed in sections 7.2.1 through 7.2.8
7.1. Descriptors 7.1. Descriptors
The parameters to a command are termed Descriptors. A Descriptor con- The parameters to a command are termed Descriptors. A Descriptor con-
sists of a name and a list of items. Some items may have values. Many sists of a name and a list of items. Some items may have values. Many
Commands share common Descriptors. This subsection enumerates these Commands share common Descriptors. This subsection enumerates these
Descriptors. Descriptors may be returned as output from a command. Descriptors. Descriptors may be returned as output from a command.
Parameters and parameter usage specific to a given Command type are Parameters and parameter usage specific to a given Command type are
described in the subsection that describes the Command. described in the subsection that describes the Command.
skipping to change at page 21, line 45 skipping to change at page 22, line 44
the command initiator is instructing the command responder to use the command initiator is instructing the command responder to use
for the specified parameter. for the specified parameter.
2. Under-specified parameters, using the CHOOSE value, allow the com- 2. Under-specified parameters, using the CHOOSE value, allow the com-
mand responder to choose any value it can support. mand responder to choose any value it can support.
3. Over-specified parameters have a list of potential values. The 3. Over-specified parameters have a list of potential values. The
list order specifies the command initiator's order of preference of list order specifies the command initiator's order of preference of
selection. The command responder chooses one value from the selection. The command responder chooses one value from the
offered list and returns that value to the command initiator. offered list and returns that value to the command initiator.
Unspecified mandatory parameters (i.e. mandatory parameters not
Unspecified mandatory parameters (i.e. mandatory parameters not speci- specified in a descriptor) result in the command responder retain-
fied in a descriptor) result in the command responder retaining the pre- ing the previous value for that parameter. Unspecified optional
vious value for that parameter. Unspecified optional parameters result parameters result in the command responder using the default value
in the command responder using the default value of the parameter. When- of the parameter. Whenever a parameter is underspecified or over-
ever a parameter is underspecified or overspecified, the descriptor con- specified, the descriptor containing the value chosen by the
taining the value chosen by the responder is included as output from the responder is included as output from the command.
command.
Each command specifies the TerminationId the command operates on. This Each command specifies the TerminationId the command operates on. This
Internet draft MEGACO Protocol February 8, 2000
TerminationId may be "wildcarded". When the TerminationId of a command TerminationId may be "wildcarded". When the TerminationId of a command
is wildcarded, the effect shall be as if the command was repeated with is wildcarded, the effect shall be as if the command was repeated with
Internet draft MEGACO Protocol February 21, 2000
each of the TerminationIds matched. each of the TerminationIds matched.
7.1.2. Modem Descriptor 7.1.2. Modem Descriptor
The Modem descriptor specifies the modem type and parameters, if any, The Modem descriptor specifies the modem type and parameters, if any,
required for use in e.g. H.324 and text conversation. The descriptor required for use in e.g. H.324 and text conversation. The descriptor
includes the following modem types: V.18, V.22, V.22bis, V.32, V.32bis, includes the following modem types: V.18, V.22, V.22bis, V.32, V.32bis,
V.34, V.90, V.91, Synchronous ISDN, and allows for extensions. By V.34, V.90, V.91, Synchronous ISDN, and allows for extensions. By
default, no modem descriptor is present in a Termination. default, no modem descriptor is present in a Termination.
skipping to change at page 22, line 33 skipping to change at page 23, line 31
the media and the bearers. The descriptor includes the multiplex type: the media and the bearers. The descriptor includes the multiplex type:
* H.221 * H.221
* H.223, * H.223,
* H.226, * H.226,
* V.76, * V.76,
* Possible Extensions * Possible Extensions and a set of TerminationIDs representing the
multiplexed inputs, in order. For example:
and a set of TerminationIDs representing the multiplexed inputs, in
order. For example:
Mux = H.221{ MyT3/1/2, MyT3/2/13, MyT3/3/6, MyT3/21/22} Mux = H.221{ MyT3/1/2, MyT3/2/13, MyT3/3/6, MyT3/21/22}
7.1.4. Media Descriptor 7.1.4. Media Descriptor
The Media Descriptor specifies the parameters for all the media streams. The Media Descriptor specifies the parameters for all the media streams.
These parameters are structured into two descriptors, a Termination These parameters are structured into two descriptors, a Termination
State Descriptor, which specifies the properties of a termination that State Descriptor, which specifies the properties of a termination that
are not stream dependent, and one or more Stream Descriptors each of are not stream dependent, and one or more Stream Descriptors each of
which describes a single media stream. which describes a single media stream.
A stream is identified by a StreamID. The StreamID is used to link the A stream is identified by a StreamID. The StreamID is used to link the
streams in a Context that belong together. Multiple streams exiting a streams in a Context that belong together. Multiple streams exiting a
termination shall be synchronized with each other. Within the Stream termination shall be synchronized with each other. Within the Stream
Descriptor, there are up to three subsidiary descriptors, LocalControl, Descriptor, there are up to three subsidiary descriptors, LocalControl,
Local, and Remote. The relationship between these descriptors is thus: Local, and Remote. The relationship between these descriptors is thus:
Internet draft MEGACO Protocol February 8, 2000
Media Descriptor Media Descriptor
TerminationStateDescriptor TerminationStateDescriptor
Stream Descriptor Stream Descriptor
LocalControl Descriptor LocalControl Descriptor
Local Descriptor Local Descriptor
Internet draft MEGACO Protocol February 21, 2000
Remote Descriptor Remote Descriptor
StreamIDs are numbered from 1 upward. As a convenience a LocalControl, As a convenience a LocalControl, Local, or Remote descriptor may be
Local, or Remote descriptor may be included in the Media Descriptor included in the Media Descriptor without an enclosing Stream descriptor.
without an enclosing Stream descriptor. In this case, the StreamID is In this case, the StreamID is assumed to be 1.
assumed to be 1.
7.1.5. Termination State Descriptor 7.1.5. Termination State Descriptor
The Termination State Descriptor contains the ServiceStates property, The Termination State Descriptor contains the ServiceStates property,
the EventBuffer flag and properties of a termination (defined in Pack- the EventBufferControl property and properties of a termination (defined
ages) that are not stream specific. in Packages) that are not stream specific.
The ServiceStates property describes the overall state of the termina- The ServiceStates property describes the overall state of the termina-
tion (not stream-specific). A Termination can be in one of the follow- tion (not stream-specific). A Termination can be in one of the follow-
ing states: "test", "out of service", or "in service". The "test" state ing states: "test", "out of service", or "in service". The "test" state
indicates that the termination is not used for normal traffic, but for indicates that the termination is being tested. The state "out of ser-
testing. A Termination with state "test" cannot be seized for traffic. vice" indicates that the termination cannot be used for traffic. The
The state "out of service" indicates a fault in the termination and can- state "in service" indicates that a termination can be used or is being
not be used for traffic. The state "in service" indicates that a termi- used for normal traffic. "in service" is the default state.
nation can be used or is being used for normal traffic. "in service" is
the default state.
Values assigned to Properties may be simple values Values assigned to Properties may be simple values
(integer/string/enumeration) or may be underspecified, where more than (integer/string/enumeration) or may be underspecified, where more than
one value is supplied and the MG may make a choice: one value is supplied and the MG may make a choice:
* Alternative Values - multiple values in a list, one of which must * Alternative Values - multiple values in a list, one of which must
be selected be selected
* Ranges - minimum and maximum values, any value between min and max * Ranges - minimum and maximum values, any value between min and max
must be selected, boundary values included must be selected, boundary values included
* Greater Than/Less Than - value must be greater/less than specified * Greater Than/Less Than - value must be greater/less than specified
value value
* CHOOSE Wildcard - the MG chooses from the allowed values for the * CHOOSE Wildcard - the MG chooses from the allowed values for the
property The EventBuffer flag specifies whether events are buffered property The EventBufferControl property specifies whether events
following detection of an event in the Events Descriptor, or pro- are buffered following detection of an event in the Events Descrip-
cessed immediately. See section 7.1.9 for details. tor, or processed immediately. See section 7.1.9 for details.
Internet draft MEGACO Protocol February 8, 2000
7.1.6. Stream Descriptor 7.1.6. Stream Descriptor
A Stream descriptor specifies the parameters of a single bi-directional A Stream descriptor specifies the parameters of a single bi-directional
stream. These parameters are structured into three descriptors: one stream. These parameters are structured into three descriptors: one
that contains termination properties specific to a stream and one each that contains termination properties specific to a stream and one each
for local and remote flows. The Stream Descriptor includes a StreamID for local and remote flows. The Stream Descriptor includes a StreamID
which identifies the stream. Streams are created by specifiying a new which identifies the stream. Streams are created by specifying a new
StreamID on one of the terminations in a Context. A stream is deleted by StreamID on one of the terminations in a Context. A stream is deleted by
setting empty Local and Remote descriptors for the stream with Reserve setting empty Local and Remote descriptors for the stream with
in LocalControl set to "false" on all terminations in the context which
previously supported that stream.
If a termination is moved from one context to another, the following
applies:
* if a streamID of an active stream in the moved termination matches Internet draft MEGACO Protocol February 21, 2000
a streamID in the context it was moved to, the associated stream
remains active on that termination;
* if a streamID of an active stream in the moved termination does not ReserveGroup and ReserveValue in LocalControl set to "false" on all ter-
match any streamID in the context it was moved to, the stream SHALL minations in the context that previously supported that stream.
be set to inactive;
* if a stream is inactive on the moved termination, it SHALL remain StreamIDs are of local significance between MGC and MG and they are
inactive in the new context until its mode is changed explicitly; assigned by the MGC. Within a context, StreamID is a means by which to
indicate which media flows are interconnected: streams with the same
StreamID are connected.
* the modes of streams on terminations already present in the new If a termination is moved from one context to another, the effect on the
context are unaffected by the fact that a termination is moved into context to which the termination is moved is the same as in the case
the context. that a new termination were added with the same StreamIDs as the moved
termination.
7.1.7. LocalControl Descriptor 7.1.7. LocalControl Descriptor
The LocalControl Descriptor contains the Mode property, the Reserve pro- The LocalControl Descriptor contains the Mode property, the ReserveGroup
perty and properties of a termination (defined in Packages) that are and ReserveValue properties and properties of a termination (defined in
stream specific, and are of interest between the MG and the MGC. Values Packages) that are stream specific, and are of interest between the MG
of properties may be underspecified as in section 7.1.5 and the MGC. Values of properties may be underspecified as in section
7.1.1.
The allowed values for the mode property are send-only, receive-only, The allowed values for the mode property are send-only, receive-only,
send/receive, inactive, and loop-back. "Send" and "receive" are with send/receive, inactive and loop-back. "Send" and "receive" are with
respect to the exterior of the context, so that, for example, a stream respect to the exterior of the context, so that, for example, a stream
set to mode=sendonly does not pass received media into the context. set to mode=sendonly does not pass received media into the context.
Signals and Events are not affected by mode. Signals and Events are not affected by mode. The boolean-valued Reserve
properties, ReserveValue and ReserveGroup, of a Termination indicate
The boolean-valued Reserve property of a Termination indicates what the what the MG is expected to do when it receives a local and/or remote
MG is expected to do when it receives a local and/or remote descriptor. descriptor.
If the value of Reserve is True, the MG SHALL reserve resources for all If the value of a Reserve property is True, the MG SHALL reserve
alternatives specified in the local and/or remote descriptors it resources for all alternatives specified in the local and/or remote
descriptors for which it currently has resources available. It SHALL
respond with the alternatives for which it reserves resources. If it
cannot not support any of the alternatives, it SHALL respond with a
reply to the MGC that contains empty local and/or remote descriptors.
Internet draft MEGACO Protocol February 8, 2000 If the value of a Reserve property is False, the MG SHALL choose one of
the alternatives specified in the local descriptor (if present) and one
of the alternatives specified in the remote descriptor (if present). If
the MG has not yet reserved resources to support the selected alterna-
tive, it SHALL reserve the resources. If, on the other hand, it already
reserved resources for the Termination addressed (because of a prior
exchange with ReserveValue and/or ReserveGroup equal to True), it SHALL
release any excess resources it reserved previously. Finally, the MG
shall send a reply to the MGC containing the alternatives for the local
and/or remote descriptor that it selected. If the MG does not have suf-
ficient resources to support any of the alternatives specified, is SHALL
currently has resources available for. It SHALL respond with the alter- Internet draft MEGACO Protocol February 21, 2000
natives it reserves resources for. If it cannot not support any of the
alternatives, it SHALL respond with a reply to the MGC that contains
empty local and/or remote descriptors.
If the value of Reserve is False, the MG SHALL choose one of the alter- respond with error 510 (insufficient resources).
natives specified in the local descriptor (if present) and one of the
alternatives specified in the remote descriptor (if present). If the MG
has not yet reserved resources to support the selected alternative, it
SHALL reserve the resources. If, on the other hand, it already reserved
resources for the Termination addressed (because of a prior exchange
with Reserve equal to True), it SHALL release any excess resources it
reserved previously. Finally, the MG shall send a reply to the MGC con-
taining the alternatives for the local and/or remote descriptor that it
selected. If the MG does not have sufficient resources to support any
of the alternatives specified, is SHALL respond with error 510 (insuffi-
cient resources).
The default value of Reserve is False. The default value of ReserveValue and ReserveGroup is False.
A new setting of the LocalControl Descriptor completely replaces the A new setting of the LocalControl Descriptor completely replaces the
previous setting of that descriptor in the MG. Thus to retain informa- previous setting of that descriptor in the MG. Thus to retain informa-
tion from the previous setting the MGC must include that information in tion from the previous setting the MGC must include that information in
the new setting. If the MGC wishes to delete some information from the the new setting. If the MGC wishes to delete some information from the
existing descriptor, it merely resends the descriptor (in a Modify com- existing descriptor, it merely resends the descriptor (in a Modify com-
mand) with the unwanted information stripped out mand) with the unwanted information stripped out.
7.1.8. Local and Remote Descriptors 7.1.8. Local and Remote Descriptors
The MGC uses Local and Remote descriptors to reserve and commit MG The MGC uses Local and Remote descriptors to reserve and commit MG
resources for media decoding and encoding for the given Stream(s) and resources for media decoding and encoding for the given Stream(s) and
Termination to which they apply. The MG includes these descriptors in Termination to which they apply. The MG includes these descriptors in
its response to indicate what it is actually prepared to support. The its response to indicate what it is actually prepared to support. The
MG SHALL include additional properties and their values in its response MG SHALL include additional properties and their values in its response
if these properties are mandatory yet not present in the requests made if these properties are mandatory yet not present in the requests made
by the MGC (e.g., by specifying detailed video encoding parameters where by the MGC (e.g., by specifying detailed video encoding parameters where
the MGC only specified the payload type). the MGC only specified the payload type).
Local refers to the media received by the MG and Remote refers to the Local refers to the media received by the MG and Remote refers to the
media sent by the MG. media sent by the MG.
When text encoding the protocol, the descriptors consist of session When text encoding the protocol, the descriptors consist of session
descriptions as defined in SDP (RFC2327), except that the "s=", "t=" and descriptions as defined in SDP (RFC2327). In session descriptions sent
"o=" lines are optional. When multiple session descriptions are provided from the MGC to the MG, the following exceptions to the syntax of RFC
in one descriptor, the "v=" lines are required as delimiters; otherwise 2327 are allowed:
they are optional. Implementations shall accept session descriptions
that are fully conformant to RFC2327. When binary encoding the protocol
the descriptor consists of groups of properties (tag-value pairs) as
Internet draft MEGACO Protocol February 8, 2000 * the "s=", "t=" and "o=" lines are optional,
specified in Annex C. Each such group may contain the parameters of a * the use of CHOOSE is allowed in place of a single parameter value,
session description. and
* the use of alternatives is allowed in place of a single parameter
value.
* When multiple session descriptions are provided in one descriptor,
the "v=" lines are required as delimiters; otherwise they are
optional in session descriptions sent to the MG. Implementations
shall accept session descriptions that are fully conformant to
RFC2327. When binary encoding the protocol the descriptor consists
of groups of properties (tag-value pairs) as specified in Annex C.
Each such group may contain the parameters of a session descrip-
tion.
Below, the semantics of the local and remote descriptors are specified Below, the semantics of the local and remote descriptors are specified
Internet draft MEGACO Protocol February 21, 2000
in detail. The specification consists of two parts. The first part in detail. The specification consists of two parts. The first part
specifies the interpretation of the contents of the descriptor. The specifies the interpretation of the contents of the descriptor. The
second part specifies the actions the MG must take upon receiving the second part specifies the actions the MG must take upon receiving the
local and remote descriptors. The actions to taken by the MG depend on local and remote descriptors. The actions to be taken by the MG depend
the value of the Reserve property of the LocalControl descriptor. on the values of the ReserveValue and ReserveGroup properties of the
LocalControl descriptor.
Either the local or the remote descriptor or both may be Either the local or the remote descriptor or both may be
* unspecified (i.e., absent), * unspecified (i.e., absent),
* empty, * empty,
* underspecified through use of CHOOSE in a property value, * underspecified through use of CHOOSE in a property value,
* fully specified, or * fully specified, or
* overspecified through presentation of multiple groups of proper- * overspecified through presentation of multiple groups of properties
ties. and possibly multiple property values in one or more of these
groups. Where the descriptors have been passed from the MGC to the
Where the descriptors have been passed from the MGC to the MG, they are MG, they are interpreted according to the rules given in section
interpreted according to the rules given in section 7.1.1, with the fol- 7.1.1, with the following additional comments for clarification:
lowing additional comments for clarification:
a) An unspecified Local or Remote descriptor is considered to be a (a) An unspecified Local or Remote descriptor is considered to be a
missing mandatory parameter. It requires the MG to use whatever missing mandatory parameter. It requires the MG to use whatever
was last specified for that descriptor. It is possible that there was last specified for that descriptor. It is possible that there
was no previously-specified value, in which case the descriptor was no previously-specified value, in which case the descriptor
concerned is ignored in further processing of the command. concerned is ignored in further processing of the command.
b) An empty Local (Remote) descriptor in a message from the MGC signi- (b) An empty Local (Remote) descriptor in a message from the MGC signi-
fies a request to release any resources reserved for the media flow fies a request to release any resources reserved for the media flow
received (sent). received (sent).
c) If multiple groups of properties are present in a Local or Remote (c) If multiple groups of properties are present in a Local or Remote
descriptor, the order of preference is descending. descriptor or multiple values within a group, the order of prefer-
ence is descending.
d) Underspecified or overspecified properties within a group of pro- (d) Underspecified or overspecified properties within a group of pro-
perties sent by the MGC are requests for the MG to choose a value perties sent by the MGC are requests for the MG to choose one or
which it can support for each of those properties. In case of an more values which it can support for each of those properties. In
overspecified property, the list of values is in descending order case of an overspecified property, the list of values is in des-
of preference. cending order of preference.
Subject to the above rules, subsequent action depends on the value of Subject to the above rules, subsequent action depends on the values of
the "Reserve" parameter in LocalControl. the ReserveValue and ReserveGroup properties in LocalControl. If
ReserveGroup is true, the MG reserves the resources required to support
any of the requested property group alternatives that it can currently
support. If ReserveValue is true, the MG reserves the resources
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
If Reserve is true, the MG reserves the resources required to support required to support any of the requested property value alternatives
any of the alternatives that it can currently support. that it can currently support.
NOTE - If a Local or Remote descriptor contains multiple groups of pro- NOTE - If a Local or Remote descriptor contains multiple groups of pro-
perties, the MG is requested to reserve resources so that it can decode perties, and ReserveGroup is true, then the MG is requested to reserve
or encode one media stream according to any of the alternatives. For resources so that it can decode or encode the media stream according to
instance, if the Local descriptor contains two groups of properties, one any of the alternatives. For instance, if the Local descriptor contains
specifying packetized G.711 A-law audio and the other G.723.1 audio, the two groups of properties, one specifying packetized G.711 A-law audio
MG reserves resources so that it can decode one audio stream encoded in and the other G.723.1 audio, the MG reserves resources so that it can
G.711 A-law format or G.723.1 format. The MG should not reserve decode one audio stream encoded in either G.711 A-law format or G.723.1
resources to decode two audio streams, one encoded in G.711 A-law and format. The MG does not have to reserve resources to decode two audio
one in G.723.1. streams simultaneously, one encoded in G.711 A-law and one in G.723.1.
The intention for the use of ReserveValue is analogous. If Reserve-
Group is true or ReserveValue is true, then the following rules apply.
* If the MG has insufficient resources to support all alternatives * If the MG has insufficient resources to support all alternatives
requested by the MGC and the MGC requested resources in both Local requested by the MGC and the MGC requested resources in both Local
and Remote, the MGC should reserve resources to support at least and Remote, the MG should reserve resources to support at least
one alternative each within Local and Remote. one alternative each within Local and Remote.
* If the MG has insufficient resources to support at least one alter- * If the MG has insufficient resources to support at least one alter-
native within a Local (Remote) descriptor received from the MGC, native within a Local (Remote) descriptor received from the MGC,
it shall return an empty Local (Remote) in response. it shall return an empty Local (Remote) in response.
* In its response to the MGC, the MG SHALL include local and remote * In its response to the MGC, when the MGC included Local and Remote
descriptors for all groups of properties it reserved resources for. descriptors, the MG SHALL include Local and Remote descriptors for
If the MG is incapable of supporting at least one of the alterna- all groups of properties and property values it reserved resources
tives within the Local (Remote) descriptor received from the MGC, for. If the MG is incapable of supporting at least one of the
it SHALL return an empty Local (Remote) descriptor. alternatives within the Local (Remote) descriptor received from the
MGC, it SHALL return an empty Local (Remote) descriptor.
* If the Mode property of the TerminationState descriptor is RecvOnly
or SendRecv, the MG must be prepared to receive media encoded
according to any of the alternatives included in its response to
the MGC.
If Reserve is False then the MG SHOULD apply the following rules to * If the Mode property of the LocalControl descriptor is RecvOnly or
resolve Local and Remote to a single alternative each: SendRecv, the MG must be prepared to receive media encoded accord-
ing to any of the alternatives included in its response to the MGC.
If ReserveGroup is False and ReserveValue is false, then the MG
SHOULD apply the following rules to resolve Local and Remote to a
single alternative each:
* If symmetric coding is not possible, the MG chooses the first * The MG chooses the first alternative in Local for which it is able
alternative in Local for which it is able to support at least one to support at least one alternative in Remote.
alternative in Remote.
* If the MG is unable to support at least one Local and one Remote * If the MG is unable to support at least one Local and one Remote
alternative, it returns Error 510 (Insufficient Resources). alternative, it returns Error 510 (Insufficient Resources).
* The MG returns its selected alternative in Local and Remote. * The MG returns its selected alternative in each of Local and
Remote. A new setting of a Local or Remote Descriptor completely
A new setting of a Local or Remote Descriptor completely replaces the replaces the previous setting of that descriptor in the MG. Thus
previous setting of that descriptor in the MG. Thus to retain informa- to retain information from the previous setting the MGC must
tion from the previous setting the MGC must include that information in
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
the new setting. If the MGC wishes to delete some information from the include that information in the new setting. If the MGC wishes to
existing descriptor, it merely resends the descriptor (in a Modify com- delete some information from the existing descriptor, it merely
mand) with the unwanted information stripped out. resends the descriptor (in a Modify command) with the unwanted
information stripped out.
7.1.9. Events Descriptor 7.1.9. Events Descriptor
The EventsDescriptor parameter contains a RequestIdentifier and a list The EventsDescriptor parameter contains a RequestIdentifier and a list
of events that the Media Gateway is requested to detect and report. The of events that the Media Gateway is requested to detect and report. The
RequestIdentifier is used to correlate the request with the notifica- RequestIdentifier is used to correlate the request with the notifica-
tions that it may trigger. Requested events include, for example, fax tions that it may trigger. Requested events include, for example, fax
tones, continuity tones, and on-hook and off-hook transitions. tones, continuity test results, and on-hook and off-hook transitions.
Each event in the descriptor contains the Event name, an optional Each event in the descriptor contains the Event name, an optional
streamID, an optional KeepActive flag, and optional parameters. The streamID, an optional KeepActive flag, and optional parameters. The
Event name consists of a Package Name (where the event is defined) and Event name consists of a Package Name (where the event is defined) and
an EventID. The ALL wildcard may be used for the EventID, indicating an EventID. The ALL wildcard may be used for the EventID, indicating
that all events from the specified package have to be detected. The that all events from the specified package have to be detected. The
default streamIDis 0, indicating that the event to be detected is not default streamIDis 0, indicating that the event to be detected is not
related to a particular media stream. Events can have parameters. This related to a particular media stream. Events can have parameters. This
allows a single event description to have some variation in meaning allows a single event description to have some variation in meaning
without creating large numbers of individual events. Further event without creating large numbers of individual events. Further event
parameters are defined in the package. parameters are defined in the package.
The MG shall send a Notify command to the MGC when it detects an event The default action of the MG, when it detects an event in the Events
in the Events Descriptor. If the EventBuffer flag is "on", following Descriptor, is to send a Notify command to the MG. Any other action is
detection of such an event, normal handling of events is suspended, and for further study.
any event found in the EventBuffer Descriptor which is subsequently
detected is added to the end of a FIFO queue, along with the time that
it was detected. A command containing an Events Descriptor which is
received when the EventBuffer flag is on causes the following sequence
to be executed:
1. The first event in the FIFO queue is examined. If it is in the If the value of the EventBufferControl property equals LockStep, follow-
Events listed in the new events descriptor, the MG shall send a ing detection of such an event, normal handling of events is suspended.
Notify command to the MGC and remove the event from the FIFO queue. Any event which is subsequently detected and occurs in the EventBuffer
The time stamp of the Notify shall be the time the event was actu- Descriptor is added to the end of the EventBuffer (a FIFO queue), along
ally detected. with the time that it was detected. The MG SHALL wait for a new
EventsDescriptor to be loaded. A new EventsDescriptor can be loaded
either as the result of receiving a command with a new EventsDescriptor,
or by activating an embedded EventsDescriptor.
2. If the event is not in the new Events Descriptor, it shall be dis- If EventBufferControl equals Off, the MG continues processing based on
the active EventsDescriptor.
In the case that an embedded EventsDescriptor being activated, the MG
continues event processing based on the newly activated EventsDescriptor
(Note - for purposes of EventBuffer handling, activation of an embedded
EventsDescriptor is equivalent to receipt of a new EventsDescriptor).
When the MG receives a command with a new EventsDescriptor, one or more
events may have been buffered in the EventBuffer in the MG. The value of
EventBufferControl then determines how the MG treats such buffered
Internet draft MEGACO Protocol February 21, 2000
events.
Case 1
If EventBufferControl = LockStep and the MG receives a new
EventsDescriptor it will check the FIFO EventBuffer and take the follow-
ing actions:
1. If the EventBuffer is empty, the MG waits for detection of events
based on the new EventsDescriptor.
2. If the EventBuffer is non-empty, the MG processes the FIFO queue
starting with the first event:
- If the event in the queue is in the events listed in the new
EventsDescriptor, the default action of the MG is to send a Notify
command to the MGC and remove the event from the EventBuffer. Any
other action is for further study. The time stamp of the Notify
shall be the time the event was actually
* detected. The MG then waits for a new EventsDescriptor. While
waiting for a new EventsDescriptor, any events matching the
EventsBufferDescriptor will be placed in the EventBuffer and the
event processing will repeat from step 1.
* If the event is not in the new EventsDescriptor, the MG SHALL dis-
card the event and repeat from step 1.
Case 2
If EventBufferControl equals Off and the MG receives a new
EventsDescriptor, it processes new events with the new EventsDescriptor.
If the MG receives a command instructing it to set the value of
EventBufferControl to Off, all events in the EventBuffer SHALL be dis-
carded. carded.
3. If the queue is empty, the sequence shall be stopped, and normal The MG may report several events in a single Transaction as long as this
event processing shall be resumed. If there are any events remain- does not unnecessarily delay the reporting of individual events.
ing in the queue, the sequence repeats.
If the EventBuffer flag is off when the new Events Descriptor is For procedures regarding transmitting the Notify command, refer to the
received, the queue is flushed, and no events are added to it. The appropriate annex for specific transport considerations.
default state of EventBuffer is off.
Internet draft MEGACO Protocol February 8, 2000 The default value of EventBufferControl is Off.
Note - Since the EventBufferControl property is in the TerminationSta-
teDescriptor, the MG might receive a command that changes the EventBuf-
ferControl property and does not include an EventsDescriptor.
Internet draft MEGACO Protocol February 21, 2000
Normally, detection of an event shall cause any active signals to stop. Normally, detection of an event shall cause any active signals to stop.
When KeepActive is specified in the event, the MG shall not interrupt When KeepActive is specified in the event, the MG shall not interrupt
any signals active on the Termination on which the event is detected. any signals active on the Termination on which the event is detected.
An event can include an Embedded Signals descriptor and/or an Embedded An event can include an Embedded Signals descriptor and/or an Embedded
Events Descriptor which, if present, replaces the current Signals/Events Events Descriptor which, if present, replaces the current Signals/Events
descriptor when the event is detected. It is possible, for example, to descriptor when the event is detected. It is possible, for example, to
specify that the dial-tone Signal be generated when an off-hook Event is specify that the dial-tone Signal be generated when an off-hook Event is
detected, or that the dial-tone Signal be stopped when a digit is detected, or that the dial-tone Signal be stopped when a digit is
detected. A media gateway controller shall not send EventsDescriptors detected. A media gateway controller shall not send EventsDescriptors
with an event both marked KeepActive and containing an embedded Sig- with an event both marked KeepActive and containing an embedded Sig-
nalsDescriptor. nalsDescriptor.
Only one level of embedding is permitted. An embedded EventsDescriptor Only one level of embedding is permitted. An embedded EventsDescriptor
SHALL NOT contain another embedded EventsDescriptor. SHALL NOT contain another embedded EventsDescriptor; an embedded
EventsDescriptor may contain an embedded SignalsDescriptor.
An Events Descriptor received by a media gateway replaces any previous An Events Descriptor received by a media gateway replaces any previous
Events Descriptor. Event notification in process shall complete, and Events Descriptor. Event notification in process shall complete, and
events detected after the command containing the new EventsDescriptor events detected after the command containing the new EventsDescriptor
executes, shall be processed according to the new EventsDescriptor. executes, shall be processed according to the new EventsDescriptor.
7.1.10. EventBuffer Descriptor 7.1.10. EventBuffer Descriptor
The EventBuffer Descriptor contains a list of events, with their parame- The EventBuffer Descriptor contains a list of events, with their parame-
ters if any, that the MG is requested to detect and buffer when no ters if any, that the MG is requested to detect and buffer when
Events Descriptor is active (See 7.1.9). EventBufferControl equals LockStep (see 7.1.9).
7.1.11. Signals Descriptor 7.1.11. Signals Descriptor
A SignalsDescriptor is a parameter that contains the set of signals that A SignalsDescriptor is a parameter that contains the set of signals that
the Media Gateway is asked to apply to a Termination. A SignalsDescrip- the Media Gateway is asked to apply to a Termination. A SignalsDescrip-
tor contains a number of signals and/or sequential signal lists. A Sig- tor contains a number of signals and/or sequential signal lists. A Sig-
nalsDescriptor may contain zero signals and sequential signal lists. nalsDescriptor may contain zero signals and sequential signal lists.
Support of sequential signal lists is optional. Support of sequential signal lists is optional.
Signals are defined in packages. Signals shall be named with a Package Signals are defined in packages. Signals shall be named with a Package
name (in which the signal is defined) and a SignalID. No wildcard shall name (in which the signal is defined) and a SignalID. No wildcard shall
be used in the SignalID. Signals that occur in a SignalsDescriptor have be used in the SignalID. Signals that occur in a SignalsDescriptor have
an optional StreamID parameter (default is 0, to indicate that the sig- an optional StreamID parameter (default is 0, to indicate that the sig-
nal is not related to a particular media stream), an optional signal nal is not related to a particular media stream), an optional signal
type (see below), an optional duration and possibly parameters defined type (see below), an optional duration and possibly parameters defined
in the package that defines the signal. This allows a single signal to in the package that defines the signal. This allows a single signal to
have some variation in meaning, obviating the need to create large have some variation in meaning, obviating the need to create large
numbers of individual signals. Finally, the optional parameter numbers of individual signals. Finally, the optional parameter
"notifyCompletion" allows the MGC to indicate that it wishes to be noti- "notifyCompletion" allows a MGC to indicate that it wishes to be noti-
fied when this signal finishes playout. When the MGC enables the Signal fied when the signal finishes playout. When the MGC enables the signal
Completion event (see section E.1.2) in an Event Descriptor, that event completion event (see section E.1.2) in an Events Descriptor, that event
is detected whenever a signal terminates and "notifyCompletion" for that
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
signal is set to TRUE.. is detected whenever a signal terminates and "notifyCompletion" for that
signal is set to TRUE. The signal completion event of section E.1.2 has
a parameter that indicates how the signal terminated: it played to com-
pletion, it was interrupted by an event, it was halted because a new
SignalsDescriptor arrived, or the signal did not complete for some other
reason.
The duration is an integer value that is expressed in hundredths of a The duration is an integer value that is expressed in hundredths of a
second. second.
There are three types of signals: There are three types of signals:
* on/off - the signal lasts until it is turned off, * on/off - the signal lasts until it is turned off,
* timeout - the signal lasts until it is turned off or a specific * timeout - the signal lasts until it is turned off or a specific
period of time elapses, period of time elapses,
skipping to change at page 30, line 51 skipping to change at page 33, line 5
Multiple signals and sequential signal lists in the same SignalsDescrip- Multiple signals and sequential signal lists in the same SignalsDescrip-
tor shall be played simultaneously. tor shall be played simultaneously.
Signals are defined as proceeding from the termination towards the exte- Signals are defined as proceeding from the termination towards the exte-
rior of the Context unless otherwise specified in a package. When the rior of the Context unless otherwise specified in a package. When the
same Signal is applied to multiple Terminations within one Transaction, same Signal is applied to multiple Terminations within one Transaction,
the MG should consider using the same resource to generate these Sig- the MG should consider using the same resource to generate these Sig-
nals. nals.
Internet draft MEGACO Protocol February 21, 2000
Production of a Signal on a Termination is stopped by application of a Production of a Signal on a Termination is stopped by application of a
new SignalsDescriptor, or detection of an Event on the Termination (see new SignalsDescriptor, or detection of an Event on the Termination (see
section 7.1.9). section 7.1.9).
Internet draft MEGACO Protocol February 8, 2000
A new SignalsDescriptor replaces any existing SignalsDescriptor. Any A new SignalsDescriptor replaces any existing SignalsDescriptor. Any
signals applied to the Termination not in the replacement descriptor signals applied to the Termination not in the replacement descriptor
shall be stopped, and new signals are applied. Signals present in both shall be stopped, and new signals are applied, except as follows. Sig-
the existing and replacement descriptor, with the same parameters in nals present in the replacement descriptor and containing the KeepActive
both, shall be continued. If the replacement descriptor contains a flagshall be continued if they are currently playing and have not
already completed. If a replacement signal descriptor contains a signal
that is not currently playing and contains the KeepActive flag, that
signal SHALL be ignored. If the replacement descriptor contains a
sequential signal list with the same identifier as the existing descrip- sequential signal list with the same identifier as the existing descrip-
tor, then tor, then
* the signal type and sequence of signals in the sequential signal * the signal type and sequence of signals in the sequential signal
list in the replacement descriptor shall be ignored, and list in the replacement descriptor shall be ignored, and
* the playing of the signals in the sequential signal list in the * the playing of the signals in the sequential signal list in the
existing descriptor shall not be interrupted. existing descriptor shall not be interrupted.
7.1.12. Audit Descriptor 7.1.12. Audit Descriptor
Specifies what information is to be audited. The Audit Descriptor The Audit Descriptor specifies what information is to be audited. The
specifies the list of descriptors to be returned. Audit may be used in Audit Descriptor specifies the list of descriptors to be returned.
any command to force the return of a descriptor even if the descriptor Audit may be used in any command to force the return of a descriptor
in the command was not present, or had no underspecified parameters. even if the descriptor in the command was not present, or had no under-
Possible items in the Audit Descriptor are: specified parameters. Possible items in the Audit Descriptor are:
________________ ________________
| Modem | | Modem |
|_______________| |________________|
| Mux | | Mux |
|_______________| |________________|
| Events | | Events |
|_______________| |________________|
| Media | | Media |
|_______________| |________________|
| Signals | | Signals |
|_______________| |________________|
| ObservedEvents| | ObservedEvents|
|_______________| |________________|
| DigitMap | | DigitMap |
|_______________| |________________|
| Statistics | | Statistics |
|_______________| |________________|
| Packages | | Packages |
Internet draft MEGACO Protocol February 21, 2000
|_______________| |_______________|
| EventBuffer | | EventBuffer |
|_______________| |_______________|
Audit may be empty, in which case, no descriptors are returned. This is Audit may be empty, in which case, no descriptors are returned. This is
useful in Subtract, to inhibit return of statistics, especially when useful in Subtract, to inhibit return of statistics, especially when
using wildcard. using wildcard.
Internet draft MEGACO Protocol February 8, 2000
7.1.13. ServiceChange Descriptor 7.1.13. ServiceChange Descriptor
The ServiceChangeDescriptor contains the following parameters: The ServiceChangeDescriptor contains the following parameters:
* ServiceChangeMethod * ServiceChangeMethod
* ServiceChangeReason * ServiceChangeReason
* ServiceChangeAddress * ServiceChangeAddress
skipping to change at page 32, line 37 skipping to change at page 34, line 45
See section 7.2.8 See section 7.2.8
7.1.14. DigitMap Descriptor 7.1.14. DigitMap Descriptor
A DigitMap is a dialing plan resident in the Media Gateway used for A DigitMap is a dialing plan resident in the Media Gateway used for
detecting and reporting digit events received on a Termination. The detecting and reporting digit events received on a Termination. The
DigitMap Descriptor contains a DigitMap name and the DigitMap to be DigitMap Descriptor contains a DigitMap name and the DigitMap to be
assigned. A digit map may be preloaded into the MG by management action assigned. A digit map may be preloaded into the MG by management action
and referenced by name in an EventsDescriptor, may be defined dynami- and referenced by name in an EventsDescriptor, may be defined dynami-
cally and subsequently referenced by name, or the actual digitmap itself cally and subsequently referenced by name, or the actual digitmap itself
may be specified in the EventsDescriptor. may be specified in the EventsDescriptor. It is permissible for a digit
map completion event within an Events Descriptor to refer by name to a
DigitMap which is defined by a DigitMap Descriptor within the same com-
mand, regardless of the transmitted order of the respective descriptors.
DigitMaps defined in a DigitMapDescriptor can occur in any of the stan- DigitMaps defined in a DigitMapDescriptor can occur in any of the stan-
dard Termination manipulation Commands of the protocol. A DigitMap, dard Termination manipulation Commands of the protocol. A DigitMap,
once defined, can be used on all Terminations specified by the (possibly once defined, can be used on all Terminations specified by the (possibly
wildcarded) TerminationID in such a command. When a DigitMap is defined wildcarded) TerminationID in such a command. DigitMaps defined on the
dynamically in a DigitMap Descriptor:
Internet draft MEGACO Protocol February 21, 2000
root Termination are global and can be used on every Termination in the
MG, provided that a DigitMap with the same name has not been defined on
the given Termination. When a DigitMap is defined dynamically in a
DigitMap Descriptor:
* A new DigitMap is created by specifying a name that is not yet * A new DigitMap is created by specifying a name that is not yet
defined. The value shall be present. defined. The value shall be present.
* A DigitMap value is updated by supplying a new value for a name * A DigitMap value is updated by supplying a new value for a name
that is already defined. Terminations presently using the digitmap that is already defined. Terminations presently using the digitmap
shall continue to use the old definition; subsequent EventsDescrip- shall continue to use the old definition; subsequent EventsDescrip-
tors specifying the name, including any EventsDescriptor in the tors specifying the name, including any EventsDescriptor in the
command containing the DigitMap descriptor, shall use the new one. command containing the DigitMap descriptor, shall use the new one.
* A DigitMap is deleted by supplying an empty value for a name that * A DigitMap is deleted by supplying an empty value for a name that
Internet draft MEGACO Protocol February 8, 2000
is already defined. Terminations presently using the digitmap shall is already defined. Terminations presently using the digitmap shall
continue to use the old definition. continue to use the old definition.
The collection of digits according to a DigitMap may be protected by The collection of digits according to a DigitMap may be protected by
three timers, viz. a start timer (T), short timer (S), and long timer three timers, viz. a start timer (T), short timer (S), and long timer
(L). (L).
1. The start timer (T) is used prior to any digits having been dialed. 1. The start timer (T) is used prior to any digits having been dialed.
2. If the Media Gateway can determine that at least one more digit is 2. If the Media Gateway can determine that at least one more digit is
needed for a digit string to match any of the allowed patterns in needed for a digit string to match any of the allowed patterns in
the digit map, then the interdigit timer value should be set to a the digit map, then the interdigit timer value should be set to a
long (L) duration (e.g.-16 seconds). long (L) duration (e.g. 16 seconds).
3. If the digit string has matched one of the patterns in the digit 3. If the digit string has matched one of the patterns in a digit map,
map, but it but it is possible that more digits could be received which would
is possible that more digits could be received which would cause a cause a match with a different pattern, then instead of reporting
match the match immediately, the MG must apply the short timer (S) and
with a different pattern, then instead of reporting the match wait for more digits.
immediately,
the MG must apply the short timer (S) and wait for more digits.
The timers are configurable parameters to a DigitMap. The Start timer The timers are configurable parameters to a DigitMap. The Start timer
is started at the beginning of every digit map use, but can be overrid- is started at the beginning of every digit map use, but can be overrid-
den. den.
The formal syntax of the digit map is described by the DigitMap rule in The formal syntax of the digit map is described by the DigitMap rule in
the formal syntax description of the protocol (see Annex A and Annex B). the formal syntax description of the protocol (see Annex A and Annex B).
A DigitMap, according to this syntax, is defined either by a string or A DigitMap, according to this syntax, is defined either by a string or
by a list of strings. Each string in the list is an alternative event by a list of strings. Each string in the list is an alternative event
sequence, specified either as a sequence of digit map symbols or as a sequence, specified either as a sequence of digit map symbols or as a
regular expression of digit map symbols. These digit map symbols, the regular expression of digit map symbols. These digit map symbols, the
digits "0" through "9" and letters "A" through a maximum value depending digits "0" through "9" and letters "A" through a maximum value depending
on the signalling system concerned, but never exceeding "K", correspond on the signalling system concerned, but never exceeding "K", correspond
Internet draft MEGACO Protocol February 21, 2000
to specified events within a package which has been designated in the to specified events within a package which has been designated in the
Events Descriptor on the termination to which the digit map is being Events Descriptor on the termination to which the digit map is being
applied. (The mapping between events and digit map symbols is defined applied. (The mapping between events and digit map symbols is defined
in the documentation for packages associated with channel-associated in the documentation for packages associated with channel-associated
signalling systems such as DTMF, MF, or R2. Digits "0" through "9" MUST signalling systems such as DTMF, MF, or R2. Digits "0" through "9" MUST
be mapped to the corresponding digit events within the signalling system be mapped to the corresponding digit events within the signalling system
concerned. Letters should be allocated in logical fashion, facilitating concerned. Letters should be allocated in logical fashion, facilitating
the use of range notation for alternative events.) The letter "x" is the use of range notation for alternative events.)
used as a wildcard, designating any event corresponding to symbols in
the range "0"-"9". The string may also contain explicit ranges and,
more generally, explicit sets of symbols, designating alternative events
any one of which satisfies that position of the digit map. Finally, the
dot symbol "." stands for zero or more repetitions of the event selector
(event, range of events, set of alternative events, or wildcard) which
Internet draft MEGACO Protocol February 8, 2000
precedes it. As a consequence of the third timing rule above, inter- The letter "x" is used as a wildcard, designating any event correspond-
event timing while matching the dot symbol uses the short timer. ing to symbols in the range "0"-"9". The string may also contain expli-
cit ranges and, more generally, explicit sets of symbols, designating
alternative events any one of which satisfies that position of the digit
map. Finally, the dot symbol "." stands for zero or more repetitions of
the event selector (event, range of events, set of alternative events,
or wildcard) that precedes it. As a consequence of the third timing
rule above, inter-event timing while matching the dot symbol uses the
short timer by default.
In addition to these event symbols, the string may contain "L" duration In addition to these event symbols, the string may contain "S" and "L"
modifiers. An "L" designates a long event: placed in front of the inter-event timing specifiers and the "Z" duration modifier. "S" and
symbol(s) designating the event(s) which satisfy a given digit position, "L" respectively indicate that the MG should use the short (S) timer or
it indicates that that position is satisfied only if the duration of the the long (L) timer for subsequent events, over-riding the timing rules
event exceeds the long-duration threshold. The value of this threshold described above. A timer specifier following a dot specifies inter-event
is assumed to be provisioned in the MG. timing for all events matching the dot as well as for subsequent events.
If an explicit timing specifier is in effect in one alternative event
sequence, but none is given in any other candidate alternative, the
timer value set by the explicit timing specifier must be used. If all
sequences with explicit timing controls are dropped from the candidate
set, timing reverts to the default rules given above. Finally, if con-
flicting timing specifiers are in effect in different alternative
sequences, the results are undefined.
A digit map is active while the event descriptor which invoked it is A "Z" designates a long duration event: placed in front of the symbol(s)
active and it has not completed. A digit map completes when: designating the event(s) which satisfy a given digit position, it indi-
cates that that position is satisfied only if the duration of the event
exceeds the long-duration threshold. The value of this threshold is
assumed to be provisioned in the MG. A digit map is active while the
events descriptor which invoked it is active and it has not completed.
A digit map completes when:
* a timer has expired, or * a timer has expired, or
* an alternative event sequence has been matched and no other alter- * an alternative event sequence has been matched and no other alter-
native event sequence in the digit map could be matched through native event sequence in the digit map could be matched through
detection of an additional event (unambiguous match), or detection of an additional event (unambiguous match), or
* an event has been detected such that a match to a complete alterna- * an event has been detected such that a match to a complete
tive event sequence of the digit map will be impossible no matter
what additional events are received. Internet draft MEGACO Protocol February 21, 2000
alternative event sequence of the digit map will be impossible no
matter what additional events are received.
Upon completion, a digit map completion event as defined in the package Upon completion, a digit map completion event as defined in the package
providing the events being mapped into the digit map shall be generated. providing the events being mapped into the digit map shall be generated.
At that point the digit map is deactivated. Subsequent events in the
package are processed as per the currently active event processing
mechanisms.
Pending completion, successive events shall be processed according to Pending completion, successive events shall be processed according to
the following rules: the following rules:
The "current dial string", an internal variable, is initially empty. The 1. The "current dial string", an internal variable, is initially
set of candidate alternative event sequences includes all of the alter- empty. The set of candidate alternative event sequences includes
natives specified in the digit map. all of the alternatives specified in the digit map.
At each step, a timer is set to wait for the next event. The rules for 2. At each step, a timer is set to wait for the next event, based
determining how long to wait are listed above. If the timer expires and either on the default timing rules given above or on explicit tim-
a member of the candidate set of alternatives is fully satisfied, a ing specified in one or more alternative event sequences. If the
timeout completion with full match is reported. If the timer expires and timer expires and a member of the candidate set of alternatives is
part or none of any candidate alternative is satisfied, a timeout com- fully satisfied, a timeout completion with full match is reported.
pletion with partial match is reported. If the timer expires and part or none of any candidate alternative
is satisfied, a timeout completion with partial match is reported.
If an event is detected before the timer expires, it is mapped to a igit 3. If an event is detected before the timer expires, it is mapped to a
string symbol and added to the end of the current dial string. The dura- digit string symbol and provisionally added to the end of the
tion of the event (long or not long) is noted if and only if this is current dial string. The duration of the event (long or not long)
relevant in the current symbol position (because at least one of the is noted if and only if this is relevant in the current symbol
candidate alternative event sequences includes the "L" modifier at this position (because at least one of the candidate alternative event
position in the sequence). sequences includes the "Z" modifier at this position in the
sequence).
The current dial string is compared to the candidate alternative event 4. The current dial string is compared to the candidate alternative
sequences, and any of these which do not match are discarded from the event sequences. If and only if a sequence expecting a long-
duration event at this position is matched (i.e. the event had long
duration and met the specification for this position), then any
alternative event sequences not specifying a long duration event at
this position are discarded, and the current dial string is modi-
fied by inserting a "Z" in front of the symbol representing the
latest event. Any sequence expecting a long-duration event at this
position but not matching the observed event is discarded from the
candidate set. If alternative event sequences not specifying a
long duration event in the given position remain in the candidate
set after application of the above rules, the observed event dura-
tion is treated as irrelevant in assessing matches to them. If
exactly one candidate remains, a completion event is generated
indicating an unambiguous match. If no candidates remain, the
latest event is removed from the current dial string and a
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
candidate set. If a sequence expecting a long-duration event at this completion event is generated indicating full match if one of the
position is matched (i.e. the event had long duration and met the candidates from the previous step was fully satisfied before the
specification for this position), then any alternative event sequences latest event was detected, or partial match otherwise. The event
not specifying a long duration event at this position are discarded, and removed from the current dial string will then be reported as per
the current dial string is modified by inserting an "L" in front of the the currently active event processing mechanisms.
symbol representing the latest event. If no sequence expecting a long-
duration event at this position is matched, any such sequences are dis-
carded from the candidate set, but the observed event duration is
treated as irrelevant in assessing matches to the remaining candidates.
If exactly one candidate remains, a completion event is generated indi- 5. If no completion event is reported out of step 5 (because the can-
cating an unambiguous match. If no candidates remain, but one of the didate set still contains more than one alternative event
candidates from the previous step was fully satisfied before the latest sequence), processing returns to step 2. A digit map is activated
event was detected, a completion event is generated indicating a full whenever a new event descriptor is applied to the termination or
match and an extra event. If no candidates remain and no candidate from embedded event descriptor is activated, and that event descriptor
the previous step was fully satisfied before the latest event was contains a digit map completion event which itself contains a digit
detected, a completion event is generated indicating a partial match and map parameter. Each new activation of a digit map begins at step 1
an extra event. If multiple candidates remain, steps 1 through 4 are of the above procedure, with a clear current dial string. Any pre-
repeated. vious contents of the current dial string from an earlier activa-
tion are lost. While the digit map is activated, detection is
enabled for all events defined in the package containing the speci-
fied digit map completion event. Normal event behaviour (e.g.
stopping of signals unless the digit completion event has the
KeepActive flag enabled) continues to apply for each such event
detected, except that the events in the package containing the
specified digit map completion event other than the completion
event itself are not individually notified. Note that if a package
contains a digit map completion event, then an event specification
consisting of the package name with a wildcarded ItemID (Property
Name) will activate a digit map if the event includes a digit map
parameter. Regardless of whether a digit map is activated, this
form of event specification will cause the individual events to be
reported to the MGC as they are detected.
As an example, consider the following dial plan: As an example, consider the following dial plan:
_______________________________________________________ _____________________________________________________________________
| 0 | Local operator | | 0 | Local operator |
| 00 | Long distance operator | | 00 | Long distance operator |
| xxxx | Local extension number | | xxxx | Local extension number(starts with 1-7)|
| 8xxxxxxx | Local number | | 8xxxxxxx | Local number |
| #xxxxxxx | Off-site extension | | #xxxxxxx | Off-site extension |
| *xx | Star services | | *xx | Star services |
| 91xxxxxxxxxx | Long distance number | | 91xxxxxxxxxx | Long distance number |
| 9011 + up to 15 digits | International number | | 9011 + up to 15 digits | International number |
|__________________________|___________________________| |__________________________|_________________________________________|
If the DTMF detection package described in Annex E (section E.6) is used If the DTMF detection package described in Annex E (section E.6) is used
to collect the dialed digits, then the dialing plan shown above results to collect the dialled digits, then the dialling plan shown above
in the following digit map: results in the following digit map:
Internet draft MEGACO Protocol February 21, 2000
(0 | 00 | [1-7]xxx | 8xxxxxxx | Fxxxxxxx | Exx | 91xxxxxxxxxx | 9011x. ) (0 | 00 | [1-7]xxx | 8xxxxxxx | Fxxxxxxx | Exx | 91xxxxxxxxxx | 9011x. )
7.1.15. Statistics Descriptor 7.1.15. Statistics Descriptor
The Statistics parameter provides information describing the status and The Statistics parameter provides information describing the status and
usage of a Termination during its existence within a specific Context. usage of a Termination during its existence within a specific Context.
There is a set of standard statistics kept for each termination where There is a set of standard statistics kept for each termination where
appropriate (number of octets sent and received for example). The par- appropriate (number of octets sent and received for example). The par-
ticular statistical properties that are reported for a given Termination ticular statistical properties that are reported for a given Termination
Internet draft MEGACO Protocol February 8, 2000
are determined by the Packages realized by the Termination. By default, are determined by the Packages realized by the Termination. By default,
statistics are reported when the Termination is Subtracted from the Con- statistics are reported when the Termination is Subtracted from the Con-
text. This behavior can be overridden by including an empty Audit- text. This behavior can be overridden by including an empty Audit-
Descriptor in the Subtract command. Statistics may also be returned Descriptor in the Subtract command. Statistics may also be returned
from the AuditValue command, or any Add/Move/Modify command using the from the AuditValue command, or any Add/Move/Modify command using the
Audit descriptor. Audit descriptor.
Statistics are cumulative; reporting Statistics does not reset them. Statistics are cumulative; reporting Statistics does not reset them.
Statistics are reset when a Termination is Subtracted from a Context. Statistics are reset when a Termination is Subtracted from a Context.
7.1.16. Packages Descriptor 7.1.16. Packages Descriptor
Used only with the AuditValue command, the PackageDescriptor returns a Used only with the AuditValue command, the PackageDescriptor returns a
list of Packages realized by the Termination. list of Packages realized by the Termination.
7.1.17. ObservedEvents Descriptor 7.1.17. ObservedEvents Descriptor
ObservedEvents is supplied with the Notify command to inform the MGC of ObservedEvents is supplied with the Notify command to inform the MGC of
which event(s) were detected. Used with the AuditValue command, the which event(s) were detected. Used with the AuditValue command, the
ObservedEventsDescriptor returns events in the event buffer which have ObservedEventsDescriptor returns events in the event buffer which have
not been Notified. In addition, if a digit map is active, the Obser- not been Notified. ObservedEvents contains the RequestIdentifier of the
vedEventsDescriptor shall contain a digit map completion event as EventsDescriptor that triggered the notification, the event(s) detected
defined in the package whose events are being mapped. This event shall and the detection time(s). Detection times are reported with a precision
show the contents of the current dial string at the time the audit of hundredths of a second. Time is expressed in UTC.
request was processed. ObservedEvents contains the RequestIdentifier of
the EventsDescriptor that triggered the notification, the event(s)
detected and the detection time(s). Detection times are reported with a
precision of hundredths of a second. Time is expressed in UTC.
7.1.18. Topology Descriptor 7.1.18. Topology Descriptor
A topology descriptor is used specify flow directions between termina- A topology descriptor is used to specify flow directions between termi-
tions in a Context. Contrary to the descriptors in previous sections, nations in a Context. Contrary to the descriptors in previous sections,
the topology descriptor applies to a Context instead of a Termination. the topology descriptor applies to a Context instead of a Termination.
The default topology of a Context is that each termination's transmis- The default topology of a Context is that each termination's transmis-
sion is received by all other terminations. The Topology Descriptor is sion is received by all other terminations. The Topology Descriptor is
optional to implement. optional to implement.
The Topology Descriptor occurs before the commands in an action. It is The Topology Descriptor occurs before the commands in an action. It is
possible to have an action containing only a Topology Descriptor, pro- possible to have an action containing only a Topology Descriptor, pro-
vided that the context to which the action applies already exists. vided that the context to which the action applies already exists.
A topology descriptor consists of a sequence of triples of the form (T1, A topology descriptor consists of a sequence of triples of the form (T1,
Internet draft MEGACO Protocol February 21, 2000
T2, association). T1 and T2 specify Terminations within the Context, T2, association). T1 and T2 specify Terminations within the Context,
possibly using the ALL or CHOOSE wildcard. The association specifies possibly using the ALL or CHOOSE wildcard. The association specifies
how media flows between these two Terminations as follows. how media flows between these two Terminations as follows.
* (T1, T2, isolate) means that the Terminations matching T2 do not * (T1, T2, isolate) means that the Terminations matching T2 do not
Internet draft MEGACO Protocol February 8, 2000
receive media from the Terminations matching T1, nor vice versa. receive media from the Terminations matching T1, nor vice versa.
* (T1, T2, oneway) means that the Terminations that match T2 receive * (T1, T2, oneway) means that the Terminations that match T2 receive
media from the Terminations matching T1, but not vice versa. In media from the Terminations matching T1, but not vice versa. In
this case use of the ALL wildcard such that there are Terminations this case use of the ALL wildcard such that there are Terminations
that match both T1 and T2 is not allowed. that match both T1 and T2 is not allowed.
* (T1, T2, bothway) means that the Terminations matching T2 receive * (T1, T2, bothway) means that the Terminations matching T2 receive
media from the Terminations matching T1, and vice versa. In this media from the Terminations matching T1, and vice versa. In this
case it is allowed to use wildcards such that there are Termina- case it is allowed to use wildcards such that there are Termina-
skipping to change at page 37, line 28 skipping to change at page 40, line 33
tion that matches both, no loopback is introduced; loopbacks are tion that matches both, no loopback is introduced; loopbacks are
created by setting the TerminationMode. created by setting the TerminationMode.
CHOOSE wildcards may be used in T1 and T2 as well, under the following CHOOSE wildcards may be used in T1 and T2 as well, under the following
restrictions: restrictions:
* the action (see section 8) of which the topology descriptor is part * the action (see section 8) of which the topology descriptor is part
contains an Add command in which a CHOOSE wildcard is used; contains an Add command in which a CHOOSE wildcard is used;
* if a CHOOSE wildcard occurs in T1 or T2, then a partial name SHALL * if a CHOOSE wildcard occurs in T1 or T2, then a partial name SHALL
NOT be specified. NOT be specified. The CHOOSE wildcard in a topology descriptor
matches the TerminationID that the MG assigns in the first Add com-
The CHOOSE wildcard in a topology descriptor matches the TerminationID mand that uses a CHOOSE wildcard in the same action. An existing
that the MG assigns in the first Add command that uses a CHOOSE wildcard Termination that matches T1 or T2 in the Context to which a Termi-
in the same action. An existing Termination that matches T1 or T2 in nation is added, is connected to the newly added Termination as
the Context to which a Termination is added, is connected to the newly specified by the topology descriptor. The default association when
added Termination as specified by the topology descriptor. The default a termination is not mentioned in the Topology descriptor is both-
association when a termination is not mentioned in the Topology descrip- way (if T3 is added to a context with T1 and T2 with topology
tor is bothway (if T3 is added to a context with T1 and T2 with topology
(T3,T1,oneway) it will be connected bothway to T2). (T3,T1,oneway) it will be connected bothway to T2).
The figure below and the table following it show some examples of the The figure below and the table following it show some examples of the
effect of including topology descriptors in actions. effect of including topology descriptors in actions. In these examples
it is assumed that the topology descriptors are applied in sequence.
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
Context 1 Context 2 Context 3 Context 1 Context 2 Context 3
+------------------+ +------------------+ +------------------+ +------------------+ +------------------+ +------------------+
| +----+ | | +----+ | | +----+ | | +----+ | | +----+ | | +----+ |
| | T2 | | | | T2 | | | | T2 | | | | T2 | | | | T2 | | | | T2 | |
| +----+ | | +----+ | | +----+ | | +----+ | | +----+ | | +----+ |
| ^ ^ | | ^ | | ^ | | ^ ^ | | ^ | | ^ |
| | | | | | | | | | | | | | | | | | | |
| +--+ +--+ | | +---+ | | +--+ | | +--+ +--+ | | +---+ | | +--+ |
| | | | | | | | | | | | | | | | | | | |
skipping to change at page 39, line 5 skipping to change at page 42, line 5
| | | | | | | | | | | | | | | | | | | |
| v | | v | | v v | | v | | v | | v v |
| +----+ +----+ | | +----+ +----+ | | +----+ +----+ | | +----+ +----+ | | +----+ +----+ | | +----+ +----+ |
| | T1 |<-->| T3 | | | | T1 |<-->| T3 | | | | T1 |<-->| T3 | | | | T1 |<-->| T3 | | | | T1 |<-->| T3 | | | | T1 |<-->| T3 | |
| +----+ +----+ | | +----+ +----+ | | +----+ +----+ | | +----+ +----+ | | +----+ +----+ | | +----+ +----+ |
+------------------+ +------------------+ +------------------+ +------------------+ +------------------+ +------------------+
1. T2, T3 oneway 2. T2, T3 bothway 3. T1, T2 bothway 1. T2, T3 oneway 2. T2, T3 bothway 3. T1, T2 bothway
Figure 4: Example topologies Figure 4: Example topologies
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
_______________________________________________________________________ _______________________________________________________________________
|Topology | Description | |Topology | Description |
|_________|____________________________________________________________| |_________|____________________________________________________________|
|1 |No topology descriptors. When no topology descriptors are | |1 |No topology descriptors. When no topology descriptors are |
| |included, all terminations have a both way connection to all| | |included, all terminations have a both way connection to all|
| |other terminations. | | |other terminations. |
|_________|____________________________________________________________| |_________|____________________________________________________________|
|2 |T1, T2, Isolated. Removes the connection between T1 and T2.| |2 |T1, T2, Isolate. Removes the connection between T1 and T2. |
| |T3 has a both way connection with both T1 and T2. | | |T3 has a both way connection with both T1 and T2. |
|_________|____________________________________________________________| |_________|____________________________________________________________|
|3 |T3, T2, oneway. A oneway connection from T3 to T2 (i.e. T2 | |3 |T3, T2, oneway. A oneway connection from T3 to T2 (i.e. T2 |
| |receives media flow from T3). A bothway connection between | | |receives media flow from T3). A bothway connection between |
| |T1 and T3. | | |T1 and T3. |
|_________|____________________________________________________________| |_________|____________________________________________________________|
|4 |T2, T3, oneway. A oneway connection between T2 to T3. | |4 |T2, T3, oneway. A oneway connection between T2 to T3. |
| |T1 and T3 remain bothway connected | | |T1 and T3 remain bothway connected |
|_________|____________________________________________________________| |_________|____________________________________________________________|
|5 |T2, T3 bothway. T2 is bothway connected to T3. | |5 |T2, T3 bothway. T2 is bothway connected to T3. |
skipping to change at page 39, line 47 skipping to change at page 42, line 47
Commands of the protocol. This API is shown to illustrate the Commands Commands of the protocol. This API is shown to illustrate the Commands
and their parameters and is not intended to specify implementation (e.g. and their parameters and is not intended to specify implementation (e.g.
via use of blocking function calls). It describes the input parameters via use of blocking function calls). It describes the input parameters
in parentheses after the command name and the return values in front of in parentheses after the command name and the return values in front of
the Command. This is only for descriptive purposes; the actual Command the Command. This is only for descriptive purposes; the actual Command
syntax and encoding are specified in later subsections. All parameters syntax and encoding are specified in later subsections. All parameters
enclosed by square brackets ([. . . ]) are considered optional. enclosed by square brackets ([. . . ]) are considered optional.
7.2.1. Add 7.2.1. Add
The Add Command adds a Termination to a Context.
TerminationID TerminationID
[,MediaDescriptor] [,MediaDescriptor]
[,ModemDescriptor] [,ModemDescriptor]
[,MuxDescriptor] [,MuxDescriptor]
Internet draft MEGACO Protocol February 8, 2000
[,EventsDescriptor] [,EventsDescriptor]
[,SignalsDescriptor] [,SignalsDescriptor]
Internet draft MEGACO Protocol February 21, 2000
[,DigitMapDescriptor] [,DigitMapDescriptor]
[,ObservedEventsDescriptor] [,ObservedEventsDescriptor]
[,EventBufferDescriptor] [,EventBufferDescriptor]
[,StatisticsDescriptor] [,StatisticsDescriptor]
[,PackagesDescriptor] [,PackagesDescriptor]
Add( TerminationID Add( TerminationID
[, MediaDescriptor] [, MediaDescriptor]
[, ModemDescriptor] [, ModemDescriptor]
[, MuxDescriptor] [, MuxDescriptor]
[, EventsDescriptor] [, EventsDescriptor]
skipping to change at page 41, line 5 skipping to change at page 43, line 52
The EventsDescriptor parameter is optional. If present, it provides the The EventsDescriptor parameter is optional. If present, it provides the
list of events that should be detected on the Termination. list of events that should be detected on the Termination.
The SignalsDescriptor parameter is optional. If present, it provides The SignalsDescriptor parameter is optional. If present, it provides
the list of signals that should be applied to the Termination. the list of signals that should be applied to the Termination.
The DigitMapDescriptor parameter is optional. If present, defines a The DigitMapDescriptor parameter is optional. If present, defines a
DigitMap definition that may be used in an EventsDescriptor. DigitMap definition that may be used in an EventsDescriptor.
Internet draft MEGACO Protocol February 8, 2000
The AuditDescriptor is optional. If present, the command will return The AuditDescriptor is optional. If present, the command will return
descriptors as specified in the AuditDescriptor. descriptors as specified in the AuditDescriptor.
Internet draft MEGACO Protocol February 21, 2000
All descriptors that can be modified could be returned by MG if a param- All descriptors that can be modified could be returned by MG if a param-
eter was underspecified or overspecified. ObservedEvents, Statistics, eter was underspecified or overspecified. ObservedEvents, Statistics,
and Packages, and the EventBuffer Descriptors are returned only if and Packages, and the EventBuffer Descriptors are returned only if
requested in the AuditDescriptor. Add SHALL NOT be used on a Termina- requested in the AuditDescriptor. Add SHALL NOT be used on a Termina-
tion with a serviceState of "OutofService". tion with a serviceState of "OutofService".
7.2.2. Modify 7.2.2. Modify
The Modify Command modifies the properties of a Termination.
TerminationID TerminationID
[,MediaDescriptor] [,MediaDescriptor]
[,ModemDescriptor] [,ModemDescriptor]
[,MuxDescriptor] [,MuxDescriptor]
[,EventsDescriptor] [,EventsDescriptor]
[,SignalsDescriptor] [,SignalsDescriptor]
[,DigitMapDescriptor] [,DigitMapDescriptor]
[,ObservedEventsDescriptor] [,ObservedEventsDescriptor]
[,EventBufferDescriptor] [,EventBufferDescriptor]
[,StatisticsDescriptor] [,StatisticsDescriptor]
skipping to change at page 41, line 50 skipping to change at page 44, line 45
The TerminationID may be specific if a single Termination in the Context The TerminationID may be specific if a single Termination in the Context
is to be modified. Use of wildcards in the TerminationID may be is to be modified. Use of wildcards in the TerminationID may be
appropriate for some operations. If the wildcard matches more than one appropriate for some operations. If the wildcard matches more than one
TerminationID, all possible matches are attempted, with results reported TerminationID, all possible matches are attempted, with results reported
for each one. The order of attempts when multiple TerminationIDs match for each one. The order of attempts when multiple TerminationIDs match
is not specified. The CHOOSE option is an error, as the Modify command is not specified. The CHOOSE option is an error, as the Modify command
may only be used on existing Terminations. may only be used on existing Terminations.
The remaining parameters to Modify are the same as those to Add. Possi- The remaining parameters to Modify are the same as those to Add. Possi-
ble return values are the same as those to Add. Modify SHALL NOT be ble return values are the same as those to Add.
used on a Termination with a serviceState of "OutofService".
Internet draft MEGACO Protocol February 8, 2000
7.2.3. Subtract 7.2.3. Subtract
The Subtract Command disconnects a Termination from its Context and The Subtract Command disconnects a Termination from its Context and
returns statistics on the Termination's participation in the Context. returns statistics on the Termination's participation in the Context.
TerminationID TerminationID
Internet draft MEGACO Protocol February 21, 2000
[,MediaDescriptor] [,MediaDescriptor]
[,ModemDescriptor] [,ModemDescriptor]
[,MuxDescriptor] [,MuxDescriptor]
[,EventsDescriptor] [,EventsDescriptor]
[,SignalsDescriptor] [,SignalsDescriptor]
[,DigitMapDescriptor] [,DigitMapDescriptor]
[,ObservedEventsDescriptor] [,ObservedEventsDescriptor]
[,EventBufferDescriptor] [,EventBufferDescriptor]
[,StatisticsDescriptor] [,StatisticsDescriptor]
[,PackagesDescriptor] [,PackagesDescriptor]
skipping to change at page 42, line 42 skipping to change at page 45, line 36
with results reported for each one. The order of attempts when multiple with results reported for each one. The order of attempts when multiple
TerminationIDs match is not specified. The CHOOSE option is an error, as TerminationIDs match is not specified. The CHOOSE option is an error, as
the Subtract command may only be used on existing Terminations. ALL may the Subtract command may only be used on existing Terminations. ALL may
be used as the ContextID as well as the TerminationId in a Subtract, be used as the ContextID as well as the TerminationId in a Subtract,
which would have the effect of deleting all contexts, deleting all which would have the effect of deleting all contexts, deleting all
ephemeral terminations, and returning all physical terminations to Null ephemeral terminations, and returning all physical terminations to Null
context. context.
By default, the Statistics parameter is returned to report information By default, the Statistics parameter is returned to report information
collected on the Termination or Terminations specified in the Command. collected on the Termination or Terminations specified in the Command.
The information reported applies to the Termination's or The information reported applies to the Termination's or Terminations'
Terminations'Termination's or Terminations' existence in the Context existence in the Context from which it or they are being subtracted.
from which it or they are being subtracted.
The AuditDescriptor is optional. If present, the command will return The AuditDescriptor is optional. If present, the command will return
descriptors as specified in the AuditDescriptor. Possible return descriptors as specified in the AuditDescriptor. Possible return
values are the same as those to Add. values are the same as those to Add.
When a provisioned Termination is Subtracted from a context, its pro- When a provisioned Termination is Subtracted from a context, its pro-
perty values shall revert to: perty values shall revert to:
Internet draft MEGACO Protocol February 8, 2000 * the default value, if specified for the property and not overridden
by provisioning,
* The default value, if specified for the property and not overridden
by provisioning or modification within the null context
* The provisioned value, if not overridden by modification in the
null context
* The last value set by a modification while the termination was in * otherwise, the provisioned value.
the null context.
7.2.4. Move 7.2.4. Move
The Move Command moves a Termination to another Context from its current The Move Command moves a Termination to another Context from its current
Internet draft MEGACO Protocol February 21, 2000
Context in one atomic operation. The Move command is the only command Context in one atomic operation. The Move command is the only command
that refers to a Termination in a Context different from that to which that refers to a Termination in a Context different from that to which
the command is applied. The Move command shall not be used to move Ter- the command is applied. The Move command shall not be used to move Ter-
minations to or from the null Context. minations to or from the null Context.
TerminationID TerminationID
[,MediaDescriptor] [,MediaDescriptor]
[,ModemDescriptor] [,ModemDescriptor]
[,MuxDescriptor] [,MuxDescriptor]
[,EventsDescriptor] [,EventsDescriptor]
skipping to change at page 44, line 5 skipping to change at page 46, line 42
The TerminationID specifies the Termination to be moved. It may be The TerminationID specifies the Termination to be moved. It may be
wildcarded. If the wildcard matches more than one TerminationID, all wildcarded. If the wildcard matches more than one TerminationID, all
possible matches are attempted, with results reported for each one. The possible matches are attempted, with results reported for each one. The
order of attempts when multiple TerminationIDs match is not specified. order of attempts when multiple TerminationIDs match is not specified.
By convention, the Termination is subtracted from its previous Context. By convention, the Termination is subtracted from its previous Context.
The Context to which the Termination is moved is indicated by the target The Context to which the Termination is moved is indicated by the target
ContextId in the Action. If the last remaining Termination is moved out ContextId in the Action. If the last remaining Termination is moved out
of a Context, the Context is deleted. of a Context, the Context is deleted.
Internet draft MEGACO Protocol February 8, 2000
The remaining descriptors are processed as in the Modify Command. The The remaining descriptors are processed as in the Modify Command. The
AuditDescriptor with the Statistics option, for example, would return AuditDescriptor with the Statistics option, for example, would return
statistics on the Termination just prior to the Move. Possible descrip- statistics on the Termination just prior to the Move. Possible descrip-
tors returned from Move are the same as for Add. Move SHALL NOT be used tors returned from Move are the same as for Add. Move SHALL NOT be used
on a Termination with a serviceState of "OutofService". on a Termination with a serviceState of "OutofService".
7.2.5. AuditValue 7.2.5. AuditValue
The AuditValue Command returns the current values of properties, events, The AuditValue Command returns the current values of properties, events,
signals and statistics associated with Terminations. signals and statistics associated with Terminations.
Internet draft MEGACO Protocol February 21, 2000
TerminationID TerminationID
[,MediaDescriptor] [,MediaDescriptor]
[,ModemDescriptor] [,ModemDescriptor]
[,MuxDescriptor] [,MuxDescriptor]
[,EventsDescriptor] [,EventsDescriptor]
[,SignalsDescriptor] [,SignalsDescriptor]
[,DigitMapDescriptor] [,DigitMapDescriptor]
[,ObservedEventsDescriptor] [,ObservedEventsDescriptor]
[,EventBufferDescriptor] [,EventBufferDescriptor]
[,StatisticsDescriptor] [,StatisticsDescriptor]
skipping to change at page 44, line 50 skipping to change at page 47, line 39
group of Terminations. Use of CHOOSE is an error. group of Terminations. Use of CHOOSE is an error.
The appropriate descriptors, with the current values for the Termina- The appropriate descriptors, with the current values for the Termina-
tion, are returned from AuditValue. Values appearing in multiple tion, are returned from AuditValue. Values appearing in multiple
instances of a descriptor are defined to be alternate values supported, instances of a descriptor are defined to be alternate values supported,
with each parameter in a descriptor considered independent. with each parameter in a descriptor considered independent.
ObservedEvents returns a list of events in the EventBuffer, Packages- ObservedEvents returns a list of events in the EventBuffer, Packages-
Descriptor returns a list of packages realized by the Termination. Descriptor returns a list of packages realized by the Termination.
DigitMapDescriptor returns the name or value of the current DigitMap for DigitMapDescriptor returns the name or value of the current DigitMap for
the Termination. DigitMap applied to the root Termination returns all the Termination. DigitMap requested in an AuditValue command with Ter-
named DigitMaps in the gateway. Statistics returns the current values minationID ALL returns all DigitMaps in the gateway. Statistics returns
of all statistics being kept on the Termination. Specifying an empty the current values of all statistics being kept on the Termination.
Specifying an empty Audit Descriptor results in only the TerminationID
Internet draft MEGACO Protocol February 8, 2000 being returned. This may be useful to get a list of TerminationIDs when
used with wildcard.
Audit Descriptor results in only the TerminationID being returned. This
may be useful to get a list of TerminationIDs when used with wildcard.
AuditValue results depend on the Context, viz. specific, null, or wild- AuditValue results depend on the Context, viz. specific, null, or wild-
carded. The TerminationID may be specific, or wildcarded. carded. The TerminationID may be specific, or wildcarded.
The following illustrates other information that can be obtained with The following illustrates other information that can be obtained with
the Audit Command: the Audit Command:
________________________________________________________________________ ________________________________________________________________________
|ContextID |TerminationID| Information Obtained | |ContextID |TerminationID| Information Obtained |
Internet draft MEGACO Protocol February 21, 2000
|Specific | wildcard |Audit of matching Terminations in a Context| |Specific | wildcard |Audit of matching Terminations in a Context|
|Specific | specific |Audit of a single Termination in a Context | |Specific | specific |Audit of a single Termination in a Context |
|Null | Root |Audit of Media Gateway state and events | |Null | Root |Audit of Media Gateway state and events |
|Null | wildcard |Audit of all matching Terminations | |Null | wildcard |Audit of all matching Terminations in the |
| | | Null context |
|Null | specific |Audit of a single Termination outside of | |Null | specific |Audit of a single Termination outside of |
| | |any Context | | | |any Context |
|All | wildcard |Audit of all matching Terminations and the | |All | wildcard |Audit of all matching Terminations and the |
| | |Context to which they are associated | | | |Context to which they are associated |
|All | Root | List of all ContextIds | |All | Root | List of all ContextIds |
|____________|_____________|___________________________________________| |____________|_____________|___________________________________________|
7.2.6. AuditCapabilities 7.2.6. AuditCapabilities
The AuditCapabilities Command returns the possible values of properties, The AuditCapabilities Command returns the possible values of properties,
skipping to change at page 46, line 4 skipping to change at page 48, line 42
[,StatisticsDescriptor] [,StatisticsDescriptor]
AuditCapabilities(TerminationID, AuditCapabilities(TerminationID,
AuditDescriptor) AuditDescriptor)
The appropriate descriptors, with the possible values for the Termina- The appropriate descriptors, with the possible values for the Termina-
tion are returned from AuditCapabilities. Descriptors may be repeated tion are returned from AuditCapabilities. Descriptors may be repeated
where there are multiple possible values. values. If a wildcarded where there are multiple possible values. values. If a wildcarded
response is requested, only one command return is generated, with the response is requested, only one command return is generated, with the
contents containing the union of the values of all Terminations matching contents containing the union of the values of all Terminations matching
the wildcard. This convention may reduce the volume of data required to the wildcard. This convention may reduce the volume of data required to
Internet draft MEGACO Protocol February 8, 2000
audit a group of Terminations. audit a group of Terminations.
Interpretation of what capabilities are requested for various values of Interpretation of what capabilities are requested for various values of
ContextID and TerminationID is the same as in AuditValue. ContextID and TerminationID is the same as in AuditValue.
The EventsDescriptor returns the list of possible events on the Termina- The EventsDescriptor returns the list of possible events on the Termina-
tion together with the list of all possible values for the tion together with the list of all possible values for the
EventsDescriptor Parameters. The SignalsDescriptor returns the list of EventsDescriptor Parameters. The SignalsDescriptor returns the list of
possible signals that could be applied to the Termination together with possible signals that could be applied to the Termination together with
the list of all possible values for the Signals Parameters. Statis- the list of all possible values for the Signals Parameters. Statis-
ticsDescriptor returns the names of the statistics being kept on the ticsDescriptor returns the names of the statistics being kept on the
Internet draft MEGACO Protocol February 21, 2000
termination. ObservedEventsDescriptor returns the names of active termination. ObservedEventsDescriptor returns the names of active
events on the termination. DigitMap and Packages are not legal in events on the termination. DigitMap and Packages are not legal in
AuditCapability AuditCapability
7.2.7. Notify 7.2.7. Notify
The Notify Command allows the Media Gateway to notify the Media Gateway The Notify Command allows the Media Gateway to notify the Media Gateway
Controller of events occurring within the Media Gateway. Controller of events occurring within the Media Gateway.
Notify(TerminationID, Notify(TerminationID,
ObservedEventsDescriptor) ObservedEventsDescriptor,
[ErrorDescriptor])
The TerminationID parameter specifies the Termination issuing the Notify The TerminationID parameter specifies the Termination issuing the Notify
Command. The TerminationID shall be a fully qualified name. Command. The TerminationID shall be a fully qualified name.
The ObservedEventsDescriptor contains the RequestID and a list of events The ObservedEventsDescriptor contains the RequestID and a list of events
that the Media Gateway detected in the order that they were detected. that the Media Gateway detected in the order that they were detected.
Each event in the list is accompanied by parameters associated with the Each event in the list is accompanied by parameters associated with the
event and an indication of the time that the event was detected. Notify event and an indication of the time that the event was detected. Pro-
Commands shall occur only as the result of detection of an event speci- cedures for sending Notify commands with RequestID equal to 0 are for
fied by an Events Descriptor which is active on the termination con- further study.
cerned.
The RequestID returns the RequestID parameter of the EventsDescriptor Notify Commands with RequestID not equal to 0 shall occur only as the
that triggered the Notify Command. It is used to correlate the notifi- result of detection of an event specified by an Events Descriptor which
cation with the request that triggered it. The events in the list must is active on the termination concerned. The RequestID returns the
have been requested via the triggering EventsDescriptor or embedded RequestID parameter of the EventsDescriptor that triggered the Notify
EventsDescriptor. Command. It is used to correlate the notification with the request that
triggered it. The events in the list must have been requested via the
triggering EventsDescriptor or embedded events descriptor unless the
RequestID is 0 (which is for further study).
7.2.8. ServiceChange 7.2.8. ServiceChange
The ServiceChange Command allows the Media Gateway to notify the Media The ServiceChange Command allows the Media Gateway to notify the Media
Gateway Controller that a Termination or group of Terminations is about Gateway Controller that a Termination or group of Terminations is about
to be taken out of service or has just been returned to service. The to be taken out of service or has just been returned to service. The
Media Gateway Controller may indicate that Termination(s) shall be taken Media Gateway Controller may indicate that Termination(s) shall be taken
out of or returned to service. The Media Gateway may notify the MGC out of or returned to service. The Media Gateway may notify the MGC
Internet draft MEGACO Protocol February 8, 2000
that the capability of a Termination has changed. It also allows a MGC that the capability of a Termination has changed. It also allows a MGC
to hand over control of a MG to another MGC. to hand over control of a MG to another MGC.
TerminationID TerminationID,
[ServiceChangeReplyDescriptor] [ServiceChangeDescriptor]
ServiceChange(TerminationID, ServiceChange(TerminationID,
ServiceChangeDescriptor ServiceChangeDescriptor
) )
Internet draft MEGACO Protocol February 21, 2000
The TerminationID parameter specifies the Termination(s) that are taken The TerminationID parameter specifies the Termination(s) that are taken
out of or returned to service. Wildcarding of Termination names is per- out of or returned to service. Wildcarding of Termination names is per-
mitted, with the exception that the CHOOSE mechanism shall not be used. mitted, with the exception that the CHOOSE mechanism shall not be used.
Use of the "Root" TerminationID indicates a ServiceChange affecting the Use of the "Root" TerminationID indicates a ServiceChange affecting the
entire Media Gateway. entire Media Gateway.
The ServiceChangeDescriptor contains the following parameters as The ServiceChangeDescriptor contains the following parameters as
required: required:
* ServiceChangeMethod * ServiceChangeMethod
skipping to change at page 47, line 37 skipping to change at page 50, line 28
* ServiceChangeReason * ServiceChangeReason
* ServiceChangeDelay * ServiceChangeDelay
* ServiceChangeAddress * ServiceChangeAddress
* ServiceChangeProfile * ServiceChangeProfile
* ServiceChangeVersion * ServiceChangeVersion
* ServiceChangeMGCId * ServiceChangeMgcId
* TimeStamp * TimeStamp
The ServiceChangeMethod parameter specifies the type of ServiceChange The ServiceChangeMethod parameter specifies the type of ServiceChange
that will or has occurred: that will or has occurred:
1) Graceful - indicates that the specified Terminations will be taken 1) Graceful - indicates that the specified Terminations will be taken
out of service after the specified ServiceChangeDelay; established out of service after the specified ServiceChangeDelay; established
connections are not yet affected, but the Media Gateway Controller connections are not yet affected, but the Media Gateway Controller
should refrain from establishing new connections and should attempt should refrain from establishing new connections and should attempt
to gracefully tear down existing connections. The MG should set to gracefully tear down existing connections. The MG should set
termination serviceState to "test" until the expiry of Servi- termination serviceState at the expiry of ServiceChangeDelay or the
ceChangeDelay or the removal of the termination from an active con- removal of the termination from an active context (whichever is
text (whichever is first), then set it to "out of service". first), to "out of service".
2) Forced - indicates that the specified Terminations were taken 2) Forced - indicates that the specified Terminations were taken
Internet draft MEGACO Protocol February 8, 2000
abruptly out of service and any established connections associated abruptly out of service and any established connections associated
with them were lost. The MGC is responsible for cleaning up the with them were lost. The MGC is responsible for cleaning up the
context (if any) with which the failed termination is associated. context (if any) with which the failed termination is associated.
At a minimum the termination shall be subtracted from the context. At a minimum the termination shall be subtracted from the context.
The termination serviceState should be "out of service". The termination serviceState should be "out of service".
3) Restart - indicates that service will be restored on the specified 3) Restart - indicates that service will be restored on the specified
Terminations after expiration of the ServiceChangeDelay. The ser- Terminations after expiration of the ServiceChangeDelay. The ser-
viceState should be set to "inService" upon expiry of Servi- viceState should be set to "inService" upon expiry of Servi-
ceChangeDelay. ceChangeDelay.
Internet draft MEGACO Protocol February 21, 2000
4) Disconnected - always applied with the Root TerminationID, indi- 4) Disconnected - always applied with the Root TerminationID, indi-
cates that the MG lost communication with the MGC, but it was sub- cates that the MG lost communication with the MGC, but it was sub-
sequently restored. Since MG state may have changed, the MGC may sequently restored. Since MG state may have changed, the MGC may
wish to use the Audit command to resynchronize its state with the wish to use the Audit command to resynchronize its state with the
MG's. MG's.
5) Handoff - sent from the MGC to the MG, this reason indicates that 5) Handoff - sent from the MGC to the MG, this reason indicates that
the MGC is going out of service and a new MGC association must be the MGC is going out of service and a new MGC association must be
established. Sent from the MG to the MGC, this indicates that the established. Sent from the MG to the MGC, this indicates that the
MG is attempting to establish a new association in accordance with MG is attempting to establish a new association in accordance with
a Handoff received from the MGC with which it was previously asso- a Handoff received from the MGC with which it was previously asso-
ciated. ciated.
6) Failover - sent from MG to MGC to indicate the primary MG is out of 6) Failover - sent from MG to MGC to indicate the primary MG is out of
service and a secondary MG is taking over, and sent from MG to service and a secondary MG is taking over.
(new) MGC in response to the MG having received a ServiceChange
with ServiceChangeMethod equal to Handoff.
7) Another value whose meaning is mutually understood between the MG 7) Another value whose meaning is mutually understood between the MG
and the MGC. and the MGC. The ServiceChangeReason parameter specifies the rea-
son why the ServiceChange has or will occur. It consists of an
The ServiceChangeReason parameter specifies the reason why the Servi- alphanumeric token (IANA registered) and an explanatory string.
ceChange has or will occur. It consists of an alphanumeric token (IANA
registered) and an explanatory string.
The optional ServiceChangeAddress parameter specifies the address (e.g., The optional ServiceChangeAddress parameter specifies the address (e.g.,
IP port number for IP networks) to be used for subsequent communica- IP port number for IP networks) to be used for subsequent communica-
tions. It can be specified in the input parameter descriptor or the tions. It can be specified in the input parameter descriptor or the
returned result descriptor. ServiceChangeAddress and ServiceChangeMgcId returned result descriptor. ServiceChangeAddress and ServiceChangeMgcId
parameters shall not both be present in the ServiceChangeDescriptor or parameters must not both be present in the ServiceChangeDescriptor or
the ServiceChangeResultDescriptor. The ServiceChangeAddress provides an the ServiceChangeResultDescriptor. The serviceChangeAddress provides an
address to be used within the context of the association currently being address to be used within the context of the association currently being
negotiated, while the ServiceChangeMgcId provides an alternate address negotiated, while the ServiceChangeMgcId provides an alternate address
where the MG should seek to establish another association. where the MG should seek to establish another association.
The optional ServiceChangeDelay parameter is expressed in seconds. If The optional ServiceChangeDelay parameter is expressed in seconds. If
the delay is absent or set to zero, the delay value should be considered the delay is absent or set to zero, the delay value should be considered
Internet draft MEGACO Protocol February 8, 2000
to be null. In the case of a "graceful" ServiceChangeMethod, a null to be null. In the case of a "graceful" ServiceChangeMethod, a null
delay indicates that the Media Gateway Controller should wait for the delay indicates that the Media Gateway Controller should wait for the
natural removal of existing connections and should not establish new natural removal of existing connections and should not establish new
connections. . For "graceful" only, null delay means the MG should set connections. . For "graceful" only, a null delay means the MG must not
serviceState to "test" immediately, then wait indefinitely for the ter- set serviceState "out of service" until the termination is in the null
mination to be removed from any active context before setting service- context.
State to "out of service". For "restart", null means immediate return
to service.
The optional ServiceChangeProfile parameter specifies the Profile (if The optional ServiceChangeProfile parameter specifies the Profile (if
any) of the protocol supported. The ServiceChangeProfile includes the any) of the protocol supported. The ServiceChangeProfile includes the
version of the profile supported. version of the profile supported.
The optional ServiceChangeVersion parameter contains the protocol ver- The optional ServiceChangeVersion parameter contains the protocol ver-
sion and is used if protocol version negotiation occurs (see section sion and is used if protocol version negotiation occurs (see section
11.3). 11.3).
Internet draft MEGACO Protocol February 21, 2000
The optional TimeStamp parameter specifies the actual time as kept by The optional TimeStamp parameter specifies the actual time as kept by
the sender. It can be used by the responder to determine how its notion the sender. It can be used by the responder to determine how its notion
of time differs from that of its correspondent. TimeStamp is sent with a of time differs from that of its correspondent. TimeStamp is sent with a
precision of hundredths of a second, and is expressed in UTC. precision of hundredths of a second, and is expressed in UTC.
The optional Extension parameter may contain any value whose meaning is The optional Extension parameter may contain any value whose meaning is
mutually understood by the MG and MGC. mutually understood by the MG and MGC.
A ServiceChange Command specifying the "Root" for the TerminationID and A ServiceChange Command specifying the "Root" for the TerminationID and
ServiceChangeMethod equal to Restart is a registration command by which ServiceChangeMethod equal to Restart is a registration command by which
a Media Gateway announces its existence to the Media Gateway Controller. a Media Gateway announces its existence to the Media Gateway Controller.
The Media Gateway is expected to be provisioned with the name of one The Media Gateway is expected to be provisioned with the name of one
primary and optionally some number of alternate Media Gateway Controll- primary and optionally some number of alternate Media Gateway Controll-
ers. ers. Acknowledgement of the ServiceChange Command completes the
Acknowledgement of the ServiceChange Command completes the registra- registration process. The MG may specify the transport ServiceChangeAd-
tion process. The MG may specify an address in the ServiceChangeAddress dress to be used by the MGC for sending messages in the ServiceChangeAd-
parameter of the ServiceChange request, and the MGC may also do so in dress parameter in the input ServiceChangeDescriptor. The MG may specify
the ServiceChange reply. In either case, the recipient must use the an address in the ServiceChangeAddress parameter of the ServiceChange
supplied address as the destination for all subsequent transaction request, and the MGC may also do so in the ServiceChange reply. In
requests within the association. At the same time, as indicated in sec- either case, the recipient must use the supplied address as the destina-
tion 9, transaction replies and pending indications must be sent to the tion for all subsequent transaction requests within the association. At
address from which the corresponding requests originated. This must be the same time, as indicated in section 9, transaction replies and pend-
done even if it implies extra messaging because commands and responses ing indications must be sent to the address from which the corresponding
cannot be packed together. The TimeStamp parameter shall be sent with a rquests originated. This must be done even if it implies extra messag-
registration command and its response. ing because commands and responses cannot be packed together. The
TimeStamp parameter shall be sent with a registration command and its
response.
The Media Gateway Controller may return a ServiceChangeMGCId parameter The Media Gateway Controller may return an ServiceChangeMgcId parameter
that describes the Media Gateway Controller that should preferably be that describes the Media Gateway Controller that should preferably be
contacted for further service by the Media Gateway. In this case the contacted for further service by the Media Gateway. In this case the
Media Gateway shall reissue the ServiceChange command to the new Media Media Gateway shall reissue the ServiceChange command to the new Media
Gateway Controller. The Gateway specified in a ServiceChangeMGCId, if Gateway Controller. The Gateway specified in an ServiceChangeMgcId, if
Internet draft MEGACO Protocol February 8, 2000
provided, shall be contacted before any further alternate MGCs. On a provided, shall be contacted before any further alternate MGCs. On a
HandOff message from MGC to MG, the ServiceChangeMGCId is the new MGC HandOff message from MGC to MG, the ServiceChangeMgcId is the new MGC
that will take over from the current MGC. that will take over from the current MGC.
The return from ServiceChange is empty except when the Root termina- The return from ServiceChange is empty except when the Root termina-
tionID is used. In that case it includes the following parameters as tionID is used. In that case it includes the following parameters as
required: required:
* ServiceChangeAddress, if the responding MGC wishes to specify an * ServiceChangeAddress, if the responding MGC wishes to specify an
new destination for messages from the MG for the remainder of the new destination for messages from the MG for the remainder of the
association; association;
* ServiceChangeMgcId, if the responding MGC does not wish to sustain * ServiceChangeMgcId, if the responding MGC does not wish to sustain
an association with the MG; an association with the MG;
Internet draft MEGACO Protocol February 21, 2000
* ServiceChangeProfile, if the responder wishes to negotiate the pro- * ServiceChangeProfile, if the responder wishes to negotiate the pro-
file to be used for the association; file to be used for the association;
* ServiceChangeVersion, if the responder wishes to negotiate the ver- * ServiceChangeVersion, if the responder wishes to negotiate the ver-
sion of the protocol to be used for the association. sion of the protocol to be used for the association.
The following ServiceChangeReasons are defined. This list may be The following ServiceChangeReasons are defined. This list may be
extended by an IANA registration as outlined in section 13.3 extended by an IANA registration as outlined in section 13.3
900 Service Restored 900 Service Restored
901 MG Cold Boot 901 Cold Boot
902 MG Warm Boot 902 Warm Boot
903 MGC Directed Change 903 MGC Directed Change
904 Termination malfunctioning 904 Termination malfunctioning
905 Termination taken out of service 905 Termination taken out of service
906 Loss of lower layer connectivity (e.g. downstream 906 Loss of lower layer connectivity (e.g. downstream
sync) sync)
907 Transmission Failure 907 Transmission Failure
908 MG Impending Failure 908 MG Impending Failure
909 MGC Impending Failure 909 MGC Impending Failure
910 Media Capability Failure 910 Media Capability Failure
911 Modem Capability Failure 911 Modem Capability Failure
skipping to change at page 51, line 5 skipping to change at page 53, line 40
913 Signal Capability Failure 913 Signal Capability Failure
914 Event Capability Failure 914 Event Capability Failure
915 State Loss 915 State Loss
7.2.9. Manipulating and Auditing Context Attributes 7.2.9. Manipulating and Auditing Context Attributes
The commands of the protocol as discussed in the preceding sections The commands of the protocol as discussed in the preceding sections
apply to terminations. This section specifies how contexts are manipu- apply to terminations. This section specifies how contexts are manipu-
lated and audited. lated and audited.
Internet draft MEGACO Protocol February 8, 2000
Commands are grouped into actions (see section 8). An action applies to Commands are grouped into actions (see section 8). An action applies to
one context. In addition to commands, it may contain context manipula- one context. In addition to commands, an action may contain context
tion and auditing instructions. manipulation and auditing instructions.
An action request sent to a MG may include a request to audit attributes An action request sent to a MG may include a request to audit attributes
of a context. An action may also include a request to change the attri- of a context. An action may also include a request to change the attri-
butes of a context. butes of a context.
The context properties that may be included in an action reply are used The context properties that may be included in an action reply are used
to return information to a MGC. This can be information requested by an to return information to a MGC. This can be information requested by an
audit of context attributes or details of the effect of manipulation of audit of context attributes or details of the effect of manipulation of
a context. a context.
Internet draft MEGACO Protocol February 21, 2000
If a MG receives an action which contains both a request to audit con- If a MG receives an action which contains both a request to audit con-
text attributes and a request to manipulate those attributes, the text attributes and a request to manipulate those attributes, the
response SHALL include the values of the attributes after processing the response SHALL include the values of the attributes after processing the
manipulation request. manipulation request.
7.2.10. Generic Command Syntax 7.2.10. Generic Command Syntax
The protocol can be encoded in a binary format or in a text format. The protocol can be encoded in a binary format or in a text format.
MGCs should support both encoding formats. MGs may support both for- MGCs should support both encoding formats. MGs may support both for-
mats. mats.
The protocol syntax for the binary format of the protocol is defined in The protocol syntax for the binary format of the protocol is defined in
Annex A. Annex C specifies the encoding of the Local and Remote Annex A. Annex C specifies the encoding of the Local and Remote
descriptors for use with the binary format. descriptors for use with the binary format.
A complete ABNF of the text encoding of the protocol per RFC2234 is A complete ABNF of the text encoding of the protocol per RFC2234 is
given in Annex B. SDP, as modified herein is used as the encoding of given in Annex B. SDP is used as the encoding of the Local and Remote
the Local and Remote Descriptors for use with the text encoding. Descriptors for use with the text encoding as modified in section 7.1.8.
7.3. Command Error Codes 7.3. Command Error Codes
Errors consist of an IANA registered error code and an explanatory Errors consist of an IANA registered error code and an explanatory
string. Sending the explanatory string is optional. Implementations string. Sending the explanatory string is optional. Implementations
are encouraged to append diagnostic information to the end of the are encouraged to append diagnostic information to the end of the
string. string.
When a MG reports an error to a MGC, it does so in an error descriptor. When a MG reports an error to a MGC, it does so in an error descriptor.
An error descriptor consists of an error code and optionally the associ- An error descriptor consists of an error code and optionally the associ-
ated explanatory string. ated explanatory string.
The identified error codes are: The identified error codes are:
400 - Bad Request 400 - Bad Request
401 - Protocol Error 401 - Protocol Error
402 - Unauthorized 402 - Unauthorized
Internet draft MEGACO Protocol February 8, 2000
403 - Syntax Error in Transaction 403 - Syntax Error in Transaction
404 - Syntax Error in TransactionReply 404 - Syntax Error in TransactionReply
405 - Syntax Error in TransactionPending 405 - Syntax Error in TransactionPending
406 - Version Not Supported 406 - Version Not Supported
410 - Incorrect identifier 410 - Incorrect identifier
411 - The transaction refers to an unknown ContextId 411 - The transaction refers to an unknown ContextId
412 - No ContextIDs available 412 - No ContextIDs available
421 - Unknown action or illegal combination of actions 421 - Unknown action or illegal combination of actions
422 - Syntax Error in Action 422 - Syntax Error in Action
430 - Unknown TerminationID 430 - Unknown TerminationID
431 - No TerminationID matched a wildcard 431 - No TerminationID matched a wildcard
Internet draft MEGACO Protocol February 21, 2000
432 - Out of TerminationIDs or No TerminationID available 432 - Out of TerminationIDs or No TerminationID available
433 - TerminationID is already in a Context 433 - TerminationID is already in a Context
440 - Unsupported or unknown Package 440 - Unsupported or unknown Package
441 - Missing RemoteDescriptor 441 - Missing RemoteDescriptor
442 - Syntax Error in Command 442 - Syntax Error in Command
443 - Unsupported or Unknown Command 443 - Unsupported or Unknown Command
444 - Unsupported or Unknown Descriptor 444 - Unsupported or Unknown Descriptor
445 - Unsupported or Unknown Property 445 - Unsupported or Unknown Property
446 - Unsupported or Unknown Parameter 446 - Unsupported or Unknown Parameter
447 - Descriptor not legal in this command 447 - Descriptor not legal in this command
skipping to change at page 52, line 40 skipping to change at page 55, line 29
451 - No such event in this package 451 - No such event in this package
452 - No such signal in this package 452 - No such signal in this package
453 - No such statistic in this package 453 - No such statistic in this package
454 - No such parameter value in this package 454 - No such parameter value in this package
455 - Parameter illegal in this Descriptor 455 - Parameter illegal in this Descriptor
456 - Parameter or Property appears twice in this Descriptor 456 - Parameter or Property appears twice in this Descriptor
461 - TransactionIDs in Reply do not match Request 461 - TransactionIDs in Reply do not match Request
462 - Commands in Transaction Reply do not match commands in request 462 - Commands in Transaction Reply do not match commands in request
463 - TerminationID of Transaction Reply does not match request 463 - TerminationID of Transaction Reply does not match request
464 - Missing reply in Transaction Reply 464 - Missing reply in Transaction Reply
465 - TransactionID in Transaction Pending does not match any open request 465 - TransactionID in Transaction Pending does not match any open
request
466 - Illegal Duplicate Transaction Request 466 - Illegal Duplicate Transaction Request
467 - Illegal Duplicate Transaction Reply 467 - Illegal Duplicate Transaction Reply
471 - Implied Add for Multiplex failure 471 - Implied Add for Multiplex failure
500 - Internal Gateway Error 500 - Internal Gateway Error
501 - Not Implemented 501 - Not Implemented
502 - Not ready. 502 - Not ready.
503 - Service Unavailable 503 - Service Unavailable
504 - Command Received from unauthorized entity 504 - Command Received from unauthorized entity
505 - Command Received before Restart Response 505 - Command Received before Restart Response
510 - Insufficient resources 510 - Insufficient resources
512 - Media Gateway unequipped to detect requested Event 512 - Media Gateway unequipped to detect requested Event
513 - Media Gateway unequipped to generate requested Signals 513 - Media Gateway unequipped to generate requested Signals
514 - Media Gateway cannot send the specified announcement 514 - Media Gateway cannot send the specified announcement
Internet draft MEGACO Protocol February 8, 2000
515 - Unsupported Media Type 515 - Unsupported Media Type
517 - Unsupported or invalid mode 517 - Unsupported or invalid mode
518 - Event buffer full 518 - Event buffer full
519 - Out of space to store digit map 519 - Out of space to store digit map
520 - Media Gateway does not have a digit map 520 - Media Gateway does not have a digit map
521 - Termination is "ServiceChangeing" 521 - Termination is "ServiceChangeing"
526 - Insufficient bandwidth 526 - Insufficient bandwidth
529 - Internal hardware failure 529 - Internal hardware failure
530 - Temporary Network failure 530 - Temporary Network failure
531 - Permanent Network failure 531 - Permanent Network failure
581 - Does Not Exist 581 - Does Not Exist
Internet draft MEGACO Protocol February 21, 2000
8. TRANSACTIONS 8. TRANSACTIONS
Commands between the Media Gateway Controller and the Media Gateway are Commands between the Media Gateway Controller and the Media Gateway are
grouped into Transactions, each of which is identified by a Transac- grouped into Transactions, each of which is identified by a Transac-
tionID. Transactions consist of one or more Actions. An Action con- tionID. Transactions consist of one or more Actions. An Action con-
sists of a series of Commands that are limited to operating within a sists of a series of Commands that are limited to operating within a
single Context. Consequently each Action typically specifies a Contex- single Context. Consequently each Action typically specifies a Contex-
tID. However, there are two circumstances where a specific ContextID is tID. However, there are two circumstances where a specific ContextID is
not provided with an Action. One is the case of modification of a Ter- not provided with an Action. One is the case of modification of a Ter-
mination outside of a Context. The other is where the controller mination outside of a Context. The other is where the controller
skipping to change at page 54, line 4 skipping to change at page 56, line 42
| | +---------+ | | | | +---------+ | |
| | | Command | | | | | | Command | | |
| | | 1 | | | | | | 1 | | |
| | +---------+ | | | | +---------+ | |
| +----------------------------------------------------+ | | +----------------------------------------------------+ |
| | | |
| +----------------------------------------------------+ | | +----------------------------------------------------+ |
| | Action 3 | | | | Action 3 | |
| | +---------+ +---------+ +---------+ | | | | +---------+ +---------+ +---------+ | |
| | | Command | | Command | | Command | | | | | | Command | | Command | | Command | | |
Internet draft MEGACO Protocol February 8, 2000
| | | 1 | | 2 | | 3 | | | | | | 1 | | 2 | | 3 | | |
| | +---------+ +---------+ +---------+ | | | | +---------+ +---------+ +---------+ | |
| +----------------------------------------------------+ | | +----------------------------------------------------+ |
+----------------------------------------------------------+ +----------------------------------------------------------+
Figure 5 Transactions, Actions and Commands Figure 5 Transactions, Actions and Commands
Transactions are presented as TransactionRequests. Corresponding Transactions are presented as TransactionRequests. Corresponding
responses to a TransactionRequest are received in a single reply, possi- responses to a TransactionRequest are received in a single reply, possi-
bly preceded by a number of TransactionPending messages (see section bly preceded by a number of TransactionPending messages (see section
8.2.3). 8.2.3).
Internet draft MEGACO Protocol February 21, 2000
Transactions guarantee ordered Command processing. That is, Commands Transactions guarantee ordered Command processing. That is, Commands
within a Transaction are executed sequentially. Ordering of Transactions within a Transaction are executed sequentially. Ordering of Transactions
is NOT guaranteed - transactions may be executed in any order, or simul- is NOT guaranteed - transactions may be executed in any order, or simul-
taneously. taneously.
At the first failing Command in a Transaction, processing of the remain- At the first failing Command in a Transaction, processing of the remain-
ing Commands in that Transaction stops. If a command contains a wild- ing Commands in that Transaction stops. If a command contains a wild-
carded TerminationID, the command is attempted with each of the actual carded TerminationID, the command is attempted with each of the actual
TerminationIDs matching the wildcard. A response within the Transac- TerminationIDs matching the wildcard. A response within the Transac-
tionReply is included for each matching TerminationID, even if one or tionReply is included for each matching TerminationID, even if one or
more instances generated an error. If any TerminationID matching a more instances generated an error. If any TerminationID matching a
wildcard results in an error when executed, any commands following the wildcard results in an error when executed, any commands following the
wildcarded command are not attempted. Commands may be marked as wildcarded command are not attempted. Commands may be marked as
"Optional" which can override this behaviour - if a command marked as "Optional" which can override this behaviour - if a command marked as
Optional results in an error, subsequent commands in the Transaction Optional results in an error, subsequent commands in the Transaction
will be executed. will be executed.
The TransactionReply includes the return values for the Commands that A TransactionReply includes the results for all of the Commands in the
were executed successfully, and the Command and error descriptor for any corresponding TransactionRequest. The TransactionReply includes the
Command that failed. TransactionPending is used to periodically notify return values for the Commands that were executed successfully, and the
the receiver that a Transaction has not completed yet, but is actively Command and error descriptor for any Command that failed. Transaction-
being processed. Pending is used to periodically notify the receiver that a Transaction
has not completed yet, but is actively being processed.
Applications SHOULD implement an application level timer per transac- Applications SHOULD implement an application level timer per transac-
tion. Expiration of the timer should cause a retransmission of the tion. Expiration of the timer should cause a retransmission of the
request. Receipt of a Reply should cancel the timer. Receipt of Pending request. Receipt of a Reply should cancel the timer. Receipt of Pending
should restart the timer. should restart the timer.
8.1. Common Parameters 8.1. Common Parameters
8.1.1. Transaction Identifiers 8.1.1. Transaction Identifiers
Transactions are identified by a TransactionID, which is assigned by Transactions are identified by a TransactionID, which is assigned by
sender and is unique within the scope of the sender. sender and is unique within the scope of the sender.
Internet draft MEGACO Protocol February 8, 2000
8.1.2. Context Identifiers 8.1.2. Context Identifiers
Contexts are identified by a ContextID, which is assigned by the Media Contexts are identified by a ContextID, which is assigned by the Media
Gateway and is unique within the scope of the Media Gateway. The Media Gateway and is unique within the scope of the Media Gateway. The Media
Gateway Controller shall use the ContextID supplied by the Media Gateway Gateway Controller shall use the ContextID supplied by the Media Gateway
in all subsequent Transactions relating to that Context. The protocol in all subsequent Transactions relating to that Context. The protocol
makes reference to a distinguished value that may be used by the Media makes reference to a distinguished value that may be used by the Media
Gateway Controller when referring to a Termination that is currently not Gateway Controller when referring to a Termination that is currently not
associated with a Context, namely the null ContextID. associated with a Context, namely the null ContextID.
The CHOOSE wildcard is used to request that the Media Gateway create a The CHOOSE wildcard is used to request that the Media Gateway create a
Internet draft MEGACO Protocol February 21, 2000
new Context. The MGC shall not use partially specified ContextIDs con- new Context. The MGC shall not use partially specified ContextIDs con-
taining the CHOOSE wildcard. The MGC may use the ALL wildcard to taining the CHOOSE wildcard. The MGC may use the ALL wildcard to
address all Contexts on the MG. address all Contexts on the MG.
8.2. Transaction Application Programming Interface 8.2. Transaction Application Programming Interface
Following is an Application Programming Interface (API) describing the Following is an Application Programming Interface (API) describing the
Transactions of the protocol. This API is shown to illustrate the Tran- Transactions of the protocol. This API is shown to illustrate the Tran-
sactions and their parameters and is not intended to specify implementa- sactions and their parameters and is not intended to specify implementa-
tion (e.g. via use of blocking function calls). It will describe the tion (e.g. via use of blocking function calls). It will describe the
skipping to change at page 56, line 5 skipping to change at page 58, line 44
with the TransactionReply or TransactionPending response from the with the TransactionReply or TransactionPending response from the
receiver. receiver.
The ContextID parameter must specify a value to pertain to all Commands The ContextID parameter must specify a value to pertain to all Commands
that follow up to either the next specification of a ContextID parameter that follow up to either the next specification of a ContextID parameter
or the end of the TransactionRequest, whichever comes first. or the end of the TransactionRequest, whichever comes first.
The Command parameter represents one of the Commands mentioned in the The Command parameter represents one of the Commands mentioned in the
"Command Details" subsection titled "Application Programming Interface". "Command Details" subsection titled "Application Programming Interface".
Internet draft MEGACO Protocol February 8, 2000
8.2.2. TransactionReply 8.2.2. TransactionReply
The TransactionReply is invoked by the receiver. There is one reply The TransactionReply is invoked by the receiver. There is one reply
invocation per transaction. A reply contains one or more Actions, each invocation per transaction. A reply contains one or more Actions, each
of which must specify its target Context and one or more Responses per of which must specify its target Context and one or more Responses per
Context. Context.
TransactionReply(TransactionID { TransactionReply(TransactionID {
ContextID { Response ... Response }, ContextID { Response ... Response },
. . . . . .
Internet draft MEGACO Protocol February 21, 2000
ContextID { Response ... Response } }) ContextID { Response ... Response } })
The TransactionID parameter must be the same as that of the correspond- The TransactionID parameter must be the same as that of the correspond-
ing TransactionRequest. ing TransactionRequest.
The ContextID parameter must specify a value to pertain to all Responses The ContextID parameter must specify a value to pertain to all Responses
for the action. The ContextID may be specific or null. for the action. The ContextID may be specific or null.
Each of the Response parameters represents a return value as mentioned Each of the Response parameters represents a return value as mentioned
in section 7.2, or an error descriptor if the command execution encoun- in section 7.2, or an error descriptor if the command execution encoun-
skipping to change at page 57, line 5 skipping to change at page 59, line 45
encounters an error such that is cannot determine a legal Transaction, encounters an error such that is cannot determine a legal Transaction,
it will return a TransactionReply with a null TransactionID and a single it will return a TransactionReply with a null TransactionID and a single
error descriptor (403 Syntax Error in Transaction). error descriptor (403 Syntax Error in Transaction).
If the end of a transaction can not be reliably determined and one or If the end of a transaction can not be reliably determined and one or
more Actions can be parsed, it will process them and then return 403 more Actions can be parsed, it will process them and then return 403
Syntax Error in Transaction as the last action reply for the transac- Syntax Error in Transaction as the last action reply for the transac-
tion. If no Actions can be parsed, it will return 403 Syntax Error in tion. If no Actions can be parsed, it will return 403 Syntax Error in
Transaction as the only reply Transaction as the only reply
Internet draft MEGACO Protocol February 8, 2000
If the terminationID cannot be reliably determined it will send 442 Syn- If the terminationID cannot be reliably determined it will send 442 Syn-
tax Error in Command as the action reply. tax Error in Command as the action reply.
If the end of a command cannot be reliably determined it will return 442 If the end of a command cannot be reliably determined it will return 442
Syntax Error in Transaction as the reply to the last action it can Syntax Error in Transaction as the reply to the last action it can
parse. parse.
8.2.3. TransactionPending 8.2.3. TransactionPending
The receiver invokes the TransactionPending. A TransactionPending indi- The receiver invokes the TransactionPending. A TransactionPending
cates that the Transaction is actively being processed, but has not been
completed. It is used to prevent the sender from assuming the Transac- Internet draft MEGACO Protocol February 21, 2000
tionRequest was lost where the Transaction will take some time to com-
plete. indicates that the Transaction is actively being processed, but has not
been completed. It is used to prevent the sender from assuming the
TransactionRequest was lost where the Transaction will take some time to
complete.
TransactionPending(TransactionID { } ) TransactionPending(TransactionID { } )
The TransactionID parameter must must be the same as that of the The TransactionID parameter must be the same as that of the correspond-
corresponding TransactionRequest. A property of root (normalMGExecu- ing TransactionRequest. A property of root (normalMGExecutionTime) is
tionTime) is settable by the MGC to indicate the interval within which settable by the MGC to indicate the interval within which the MGC
the MGC expects a response to any transaction from the MG. Another pro- expects a response to any transaction from the MG. Another property
perty (normalMGCExecutionTime) is settable by the MGC to indicate the (normalMGCExecutionTime) is settable by the MGC to indicate the interval
interval within which the MG should expects a response to any transac- within which the MG should expects a response to any transaction from
tion from the MGC. Senders may receive more than one TransactionPending the MGC. Senders may receive more than one TransactionPending for a
for a command. If a duplicate request is received when pending, the command. If a duplicate request is received when pending, the responder
responder may send a duplicate pending immediately, or continue waiting may send a duplicate pending immediately, or continue waiting for its
for its timer to trigger another Transaction Pending. timer to trigger another Transaction Pending.
8.3. Messages 8.3. Messages
Multiple Transactions can be concatenated into a Message. Messages have Multiple Transactions can be concatenated into a Message. Messages have
a header, which includes the identity of the sender. The Message Iden- a header, which includes the identity of the sender. The Message Iden-
tifier (MID) of a message is set to a provisioned name (e.g. domain tifier (MID) of a message is set to a provisioned name (e.g. domain
address/domain name/device name) of the entity transmitting the message. address/domain name/device name) of the entity transmitting the message.
Domain name is a suggested default. Domain name is a suggested default.
Every Message contains a Version Number identifying the version of the Every Message contains a Version Number identifying the version of the
protocol the message conforms to. Versions consist of one or two protocol the message conforms to. Versions consist of one or two
digits, beginning with version 1 for the present version of the proto- digits, beginning with version 1 for the present version of the proto-
col. col.
The transactions in a message are treated independently. There is no The transactions in a message are treated independently. There is no
order implied, there is no application or protocol acknowledgement of a order implied, there is no application or protocol acknowledgement of a
message. message.
Internet draft MEGACO Protocol February 8, 2000
9. TRANSPORT 9. TRANSPORT
The transport mechanism for the protocol should allow the reliable tran- The transport mechanism for the protocol should allow the reliable tran-
sport of transactions between an MGC and MG. The transport shall remain sport of transactions between an MGC and MG. The transport shall remain
independent of what particular commands are being sent and shall be independent of what particular commands are being sent and shall be
applicable to all application states. There are several transports applicable to all application states. There are several transports
defined for the protocol, which are defined in normative Annexes to this defined for the protocol, which are defined in normative Annexes to this
document. Additional Transports may be defined as additional annexes in document. Additional Transports may be defined as additional annexes in
subsequent editions of this document, or in separate documents. For subsequent editions of this document, or in separate documents. For
transport of the protocol over IP, MGCs shall implement both TCP and transport of the protocol over IP, MGCs shall implement both TCP and
UDP/ALF, an MG shall implement TCP or UDP/ALF or both. UDP/ALF, an MG shall implement TCP or UDP/ALF or both.
The MG is provisioned with a name or address (such as DNS name or IP The MG is provisioned with a name or address (such as DNS name or IP
Internet draft MEGACO Protocol February 21, 2000
address) of a primary and zero or more secondary MGCs (see section address) of a primary and zero or more secondary MGCs (see section
7.2.8) that is the address the MG uses to send messages to the MGC. If 7.2.8) that is the address the MG uses to send messages to the MGC. If
TCP or UDP is used as the protocol transport and the port to which the TCP or UDP is used as the protocol transport and the port to which the
initial ServiceChange request is to be sent is not otherwise known, that initial ServiceChange request is to be sent is not otherwise known, that
request should be sent to the default port number for the protocol. request should be sent to the default port number for the protocol.
This port number is xxxx for text-encoded operation or yyyy for binary- This port number is 2944 for text-encoded operation or 2945 for binary-
encoded operation, for either UDP or TCP. The MGC receives the message encoded operation, for either UDP or TCP. The MGC receives the message
containing the ServiceChange request from the MG and can determine the containing the ServiceChange request from the MG and can determine the
MG's address from it. As described in section 7.2.8, either the MG or MG's address from it. As described in section 7.2.8, either the MG or
the MGC may supply an address in the ServiceChangeAddress parameter to the MGC may supply an address in the ServiceChangeAddress parameter to
which subsequent transaction requests must be addressed, but responses which subsequent transaction requests must be addressed, but responses
(including the response to the initial ServiceChange request) must (including the response to the initial ServiceChange request) must
always be sent back to the address which was the source of the always be sent back to the address which was the source of the
corresponding request. corresponding request.
9.1. Ordering of Commands 9.1. Ordering of Commands
skipping to change at page 58, line 50 skipping to change at page 61, line 37
drawbacks. For example: drawbacks. For example:
* Notify commands may be delayed and arrive at the MGC after the * Notify commands may be delayed and arrive at the MGC after the
transmission of a new command changing the EventsDescriptor transmission of a new command changing the EventsDescriptor
* If a new command is transmitted before a previous one is ack- * If a new command is transmitted before a previous one is ack-
nowledged, there is no guarantee that prior command will be exe- nowledged, there is no guarantee that prior command will be exe-
cuted before the new one. cuted before the new one.
Media Gateway Controllers that want to guarantee consistent operation of Media Gateway Controllers that want to guarantee consistent operation of
the Media Gateway may use the following rules: the Media Gateway may use the following rules. These rules are with
respect to commands that are in different transactions. Commands that
are in the same transaction are executed in order (see section 8).
1. When a Media Gateway handles several Terminations, commands per- 1. When a Media Gateway handles several Terminations, commands per-
taining to the different Terminations may be sent in parallel, for taining to the different Terminations may be sent in parallel, for
example following a model where each Termination (or group of example following a model where each Termination (or group of Ter-
minations) is controlled by its own process or its own thread.
Internet draft MEGACO Protocol February 8, 2000 2. On a Termination, there should normally be at most one outstanding
command (Add or Modify or Move), unless the outstanding commands
are in the same transaction. However, a Subtract command may be
issued at any time. In consequence, a Media Gateway may sometimes
receive a Modify command that applies to a previously subtracted
Termination. Such commands should be ignored, and an error code
should be returned.
Terminations) is controlled by its own process or its own thread. 3. On a given Termination, there should normally be at most one
2. In a given Context, there should normally be at most one outstand- Internet draft MEGACO Protocol February 21, 2000
ing command (Add or Modify or Move). However, a Subtract command
may be issued at any time. In consequence, a Media Gateway may
sometimes receive a Modify command that applies to a previously
subtracted Termination. Such commands should be ignored, and an
error code should be returned.
3. On a given Termination, there should normally be at most one out- outstanding Notify command at any time.
standing Notify command at any time. The RequestId parameter
should be used to correlate Notify commands with the triggering
notification request.
4. In some cases, an implicitly or explicitly wildcarded Subtract com- 4. In some cases, an implicitly or explicitly wildcarded Subtract com-
mand that applies to a group of Terminations may step in front of a mand that applies to a group of Terminations may step in front of a
pending Add command. The Media Gateway Controller should individu- pending Add command. The Media Gateway Controller should individu-
ally delete all connections whose completion was pending at the ally delete all Terminations for which an Add command was pending
time of the global Subtract command. Also, new Add commands for at the time of the global Subtract command. Also, new Add commands
Terminations named by the wild-carding (or implied in a Multiplex for Terminations named by the wild-carding (or implied in a Multi-
descriptor) may not be sent until the wild-carded Subtract command plex descriptor) should not be sent until the wild-carded Subtract
is acknowledged. command is acknowledged.
5. AuditValue and AuditCapability are not subject to any sequencing. 5. AuditValue and AuditCapability are not subject to any sequencing.
6. ServiceChange shall always be the first command sent by a MG as 6. ServiceChange shall always be the first command sent by a MG as
defined by the restart procedure. Any other command or response defined by the restart procedure. Any other command or response
must be delivered after this ServiceChange command. These rules do must be delivered after this ServiceChange command.
not affect the command responder, which should always respond to
commands. These rules do not affect the command responder, which should always
respond to commands.
9.2. Protection against Restart Avalanche 9.2. Protection against Restart Avalanche
In the event that a large number of Media Gateways are powered on simul- In the event that a large number of Media Gateways are powered on simul-
taneously and they were to all initiate a ServiceChange transaction, the taneously and they were to all initiate a ServiceChange transaction, the
Media Gateway Controller would very likely be swamped, leading to mes- Media Gateway Controller would very likely be swamped, leading to mes-
sage losses and network congestion during the critical period of service sage losses and network congestion during the critical period of service
restoration. In order to prevent such avalanches, the following behavior restoration. In order to prevent such avalanches, the following behavior
is suggested: is suggested:
1. When a Media Gateway is powered on, it should initiate a restart 1. When a Media Gateway is powered on, it should initiate a restart
timer to a random value, uniformly distributed between 0 and a max- timer to a random value, uniformly distributed between 0 and a max-
imum waiting delay (MWD). Care should be taken to avoid synchroni- imum waiting delay (MWD). Care should be taken to avoid synchroni-
city of the random number generation between multiple Media Gate- city of the random number generation between multiple Media Gate-
ways that would use the same algorithm. ways that would use the same algorithm.
2. The Media Gateway should then wait for either the end of this timer 2. The Media Gateway should then wait for either the end of this timer
or the detection of a local user activity, such as for example an or the detection of a local user activity, such as for example an
Internet draft MEGACO Protocol February 8, 2000
off-hook transition on a residential Media Gateway. off-hook transition on a residential Media Gateway.
3. When the timer elapses, or when an activity is detected, the Media 3. When the timer elapses, or when an activity is detected, the Media
Gateway should initiate the restart procedure. Gateway should initiate the restart procedure.
The restart procedure simply requires the MG to guarantee that the first The restart procedure simply requires the MG to guarantee that the first
message that the Media Gateway Controller sees from this MG is a Servi- message that the Media Gateway Controller sees from this MG is a Servi-
ceChange message informing the Media Gateway Controller about the res- ceChange message informing the Media Gateway Controller about the res-
tart tart
The value of MWD is a configuration parameter that depends on the type Note - The value of MWD is a configuration parameter that depends on the
of the Media Gateway. The following reasoning may be used to determine
the value of this delay on residential gateways. Internet draft MEGACO Protocol February 21, 2000
type of the Media Gateway. The following reasoning may be used to deter-
mine the value of this delay on residential gateways.
Media Gateway Controllers are typically dimensioned to handle the peak Media Gateway Controllers are typically dimensioned to handle the peak
hour traffic load, during which, in average, 10% of the lines will be hour traffic load, during which, in average, 10% of the lines will be
busy, placing calls whose average duration is typically 3 minutes. The busy, placing calls whose average duration is typically 3 minutes. The
processing of a call typically involves 5 to 6 Media Gateway Controller processing of a call typically involves 5 to 6 Media Gateway Controller
transactions between each Media Gateway and the Media Gateway Con- transactions between each Media Gateway and the Media Gateway Con-
troller. This simple calculation shows that the Media Gateway Con- troller. This simple calculation shows that the Media Gateway Con-
troller is expected to handle 5 to 6 transactions for each Termination, troller is expected to handle 5 to 6 transactions for each Termination,
every 30 minutes on average, or, to put it otherwise, about one transac- every 30 minutes on average, or, to put it otherwise, about one transac-
tion per Termination every 5 to 6 minutes on average. This suggests tion per Termination every 5 to 6 minutes on average. This suggests
skipping to change at page 61, line 4 skipping to change at page 63, line 44
a gateway that handles a T3 line. a gateway that handles a T3 line.
10. SECURITY CONSIDERATIONS 10. SECURITY CONSIDERATIONS
This section covers security when using the protocol in an IP environ- This section covers security when using the protocol in an IP environ-
ment. ment.
10.1. Protection of Protocol Connections 10.1. Protection of Protocol Connections
A security mechanism is clearly needed to prevent unauthorized entities A security mechanism is clearly needed to prevent unauthorized entities
Internet draft MEGACO Protocol February 8, 2000
from using the protocol defined in this document for setting up unau- from using the protocol defined in this document for setting up unau-
thorized calls or interfering with authorized calls. The security thorized calls or interfering with authorized calls. The security
mechanism for the protocol when transported over IP networks is IPsec mechanism for the protocol when transported over IP networks is IPsec
[RFC2401 to RFC2411]. [RFC2401 to RFC2411].
The AH header [RFC2402] affords data origin authentication, connection- The AH header [RFC2402] affords data origin authentication, connection-
less integrity and optional anti-replay protection of messages passed less integrity and optional anti-replay protection of messages passed
between the MG and the MGC. The ESP header [RFC2406] provides confiden- between the MG and the MGC. The ESP header [RFC2406] provides confiden-
tiality of messages, if desired. For instance, the ESP encryption ser- tiality of messages, if desired. For instance, the ESP encryption ser-
vice should be requested if the session descriptions are used to carry vice should be requested if the session descriptions are used to carry
session keys, as defined in SDP. session keys, as defined in SDP.
Internet draft MEGACO Protocol February 21, 2000
Implementations of the protocol defined in this document employing the Implementations of the protocol defined in this document employing the
ESP header SHALL comply with section 5 of [RFC2406], which defines a ESP header SHALL comply with section 5 of [RFC2406], which defines a
minimum set of algorithms for integrity checking and encryption. Simi- minimum set of algorithms for integrity checking and encryption. Simi-
larly, implementations employing the AH header SHALL comply with section larly, implementations employing the AH header SHALL comply with section
5 of [RFC2402], which defines a minimum set of algorithms for integrity 5 of [RFC2402], which defines a minimum set of algorithms for integrity
checking using manual keys. checking using manual keys.
Implementations SHOULD use IKE [RFC2409] to permit more robust keying Implementations SHOULD use IKE [RFC2409] to permit more robust keying
options. Implementations employing IKE SHOULD support authentication options. Implementations employing IKE SHOULD support authentication
with RSA signatures and RSA public key encryption. with RSA signatures and RSA public key encryption.
skipping to change at page 62, line 4 skipping to change at page 64, line 43
tionality, the ICV calculation should be performed across the entire tionality, the ICV calculation should be performed across the entire
transaction prepended by a synthesized IP header consisting of a 32 bit transaction prepended by a synthesized IP header consisting of a 32 bit
source IP address, a 32 bit destination address and an 16 bit UDP source IP address, a 32 bit destination address and an 16 bit UDP
encoded as 10 hex digits. When the interim AH mechanism is employed when encoded as 10 hex digits. When the interim AH mechanism is employed when
TCP is the transport Layer, the UDP Port above becomes the TCP port, and TCP is the transport Layer, the UDP Port above becomes the TCP port, and
all other operations are the same. all other operations are the same.
Implementations of the MEGACO protocol SHALL implement IPsec where the Implementations of the MEGACO protocol SHALL implement IPsec where the
underlying operating system and the transport network supports IPsec. underlying operating system and the transport network supports IPsec.
Implementations of the protocol using IPv4 SHALL implement the interim Implementations of the protocol using IPv4 SHALL implement the interim
Internet draft MEGACO Protocol February 8, 2000
AH scheme. However, this interim scheme SHALL NOT be used when the AH scheme. However, this interim scheme SHALL NOT be used when the
underlying network layer supports IPsec. IPv6 implementations are underlying network layer supports IPsec. IPv6 implementations are
assumed to support IPsec and SHALL NOT use the interim AH scheme. assumed to support IPsec and SHALL NOT use the interim AH scheme.
All implementations of the interim AH mechanism SHALL comply with sec- All implementations of the interim AH mechanism SHALL comply with sec-
tion 5 of [RFC2402] which defines a minimum set of algorithms for tion 5 of [RFC2402] which defines a minimum set of algorithms for
integrity checking using manual keys. integrity checking using manual keys.
The interim AH interim scheme does not provide protection against eaves- The interim AH interim scheme does not provide protection against eaves-
dropping; thus forbidding third parties from monitoring the connections dropping; thus forbidding third parties from monitoring the connections
set up by a given termination. Also, it does not provide protection set up by a given termination. Also, it does not provide protection
against replay attacks. These procedures do not necessarily protect against replay attacks. These procedures do not necessarily protect
Internet draft MEGACO Protocol February 21, 2000
against denial of service attacks by misbehaving MGs or misbehaving against denial of service attacks by misbehaving MGs or misbehaving
MGCs. However, they will provide an identification of these misbehaving MGCs. However, they will provide an identification of these misbehaving
entities, which should then be deprived of their authorization through entities, which should then be deprived of their authorization through
maintenance procedures. maintenance procedures.
10.3. Protection of Media Connections 10.3. Protection of Media Connections
The protocol allows the MGC to provide MGs with "session keys" that can The protocol allows the MGC to provide MGs with "session keys" that can
be used to encrypt the audio messages, protecting against eavesdropping. be used to encrypt the audio messages, protecting against eavesdropping.
skipping to change at page 63, line 5 skipping to change at page 65, line 43
waiting for the round trip to complete, and risk for example, waiting for the round trip to complete, and risk for example,
"clipping" a remote announcement, or wait for the full roundtrip "clipping" a remote announcement, or wait for the full roundtrip
and settle for slower call-set-up procedures. and settle for slower call-set-up procedures.
* Source spoofing is only effective if the attacker can obtain valid * Source spoofing is only effective if the attacker can obtain valid
pairs of source destination addresses and ports, for example by pairs of source destination addresses and ports, for example by
listening to a fraction of the traffic. To fight source spoofing, listening to a fraction of the traffic. To fight source spoofing,
one could try to control all access points to the network. But one could try to control all access points to the network. But
this is in practice very hard to achieve. this is in practice very hard to achieve.
Internet draft MEGACO Protocol February 8, 2000
An alternative to checking the source address is to encrypt and authen- An alternative to checking the source address is to encrypt and authen-
ticate the packets, using a secret key that is conveyed during the call ticate the packets, using a secret key that is conveyed during the call
set-up procedure. This will not slow down the call set- up, and provides set-up procedure. This will not slow down the call set- up, and provides
strong protection against address spoofing. strong protection against address spoofing.
11. MG-MGC CONTROL INTERFACE 11. MG-MGC CONTROL INTERFACE
The control association between MG and MGC is initiated at MG cold The control association between MG and MGC is initiated at MG cold
start, and announced by a ServiceChange message, but can be changed by start, and announced by a ServiceChange message, but can be changed by
subsequent events, such as failures or manual service events. While the subsequent events, such as failures or manual service events. While the
protocol does not have an explicit mechanism to support multiple MGCs protocol does not have an explicit mechanism to support multiple MGCs
controlling a physical MG, it has been designed to support the multiple controlling a physical MG, it has been designed to support the multiple
Internet draft MEGACO Protocol February 21, 2000
logical MG (within a single physical MG) that can be associated with logical MG (within a single physical MG) that can be associated with
different MGCs. different MGCs.
11.1. Multiple Virtual MGs 11.1. Multiple Virtual MGs
A physical Media Gateway may be partitioned into one or more Virtual A physical Media Gateway may be partitioned into one or more Virtual
MGs. A virtual MG consists of a set of statically partitioned physical MGs. A virtual MG consists of a set of statically partitioned physical
Terminations and/or sets of ephemeral Terminations. A physical Termina- Terminations and/or sets of ephemeral Terminations. A physical Termina-
tion is controlled by one MGC. The model does not require that other tion is controlled by one MGC. The model does not require that other
resources be statically allocated, just Terminations. The mechanism for resources be statically allocated, just Terminations. The mechanism for
skipping to change at page 64, line 5 skipping to change at page 66, line 44
do with respect to the physical resources it is controlling. do with respect to the physical resources it is controlling.
If recovering from the event requires manipulation of a physical If recovering from the event requires manipulation of a physical
interface's state, only one MGC should do so. These issues are resolved interface's state, only one MGC should do so. These issues are resolved
by allowing any of the MGCs to create EventsDescriptors to be notified by allowing any of the MGCs to create EventsDescriptors to be notified
of such events, but only one MGC can have read/write access to the phy- of such events, but only one MGC can have read/write access to the phy-
sical interface properties; all other MGCs have read-only access. The sical interface properties; all other MGCs have read-only access. The
management mechanism is used to designate which MGC has read/write capa- management mechanism is used to designate which MGC has read/write capa-
bility, and is designated the Master MGC. bility, and is designated the Master MGC.
Internet draft MEGACO Protocol February 8, 2000
Each virtual MG has its own Root Termination. In most cases the values Each virtual MG has its own Root Termination. In most cases the values
for the properties of the Root Termination are independently settable by for the properties of the Root Termination are independently settable by
each MGC. Where there can only be one value, the parameter is read-only each MGC. Where there can only be one value, the parameter is read-only
to all but the Master MGC. to all but the Master MGC.
ServiceChange may only be applied to a Termination or set of Termina- ServiceChange may only be applied to a Termination or set of Termina-
tions partitioned to the Virtual MG or created (in the case of ephemeral tions partitioned to the Virtual MG or created (in the case of ephemeral
Terminations) by that Virtual MG. Terminations) by that Virtual MG.
Internet draft MEGACO Protocol February 21, 2000
11.2. Cold Start 11.2. Cold Start
A MG is pre-provisioned by a management mechanism outside the scope of A MG is pre-provisioned by a management mechanism outside the scope of
this protocol with a Primary and (optionally) an ordered list of Secon- this protocol with a Primary and (optionally) an ordered list of Secon-
dary MGCs. Upon a cold start of the MG, it will issue a ServiceChange dary MGCs. Upon a cold start of the MG, it will issue a ServiceChange
command with a "Restart" method, on the Root Termination to its primary command with a "Restart" method, on the Root Termination to its primary
MGC. If the MGC accepts the MG, it will send a Transaction Accept, with MGC. If the MGC accepts the MG, it will send a Transaction Accept, with
the MGCIdToTry set to itself. If the MG receives a ServiceChangeMGCId the ServiceChangeMgcId set to itself. If the MG receives an Servi-
not equal to the MGC it contacted, it sends a ServiceChange to the MGC ceChangeMgcId not equal to the MGC it contacted, it sends a Servi-
specified in the ServiceChangeMGCId. It continues this process until it ceChange to the MGC specified in the ServiceChangeMgcId. It continues
gets a controlling MGC to accept its registration, or it fails to get a this process until it gets a controlling MGC to accept its registration,
reply. Upon failure to obtain a reply, either from the Primary MGC, or a or it fails to get a reply. Upon failure to obtain a reply, either from
designated successor, the MG tries its pre-provisioned Secondary MGCs, the Primary MGC, or a designated successor, the MG tries its pre-
in order. If the MG is unable to establish a control relationship with provisioned Secondary MGCs, in order. If the MG is unable to comply and
any MGC, it shall wait a random amount of time as described in section it has established a transport connection to the MGC, it should close
9.2 and then start contacting its primary, and if necessary, its secon- that connection. In any event, it should reject all subsequent requests
dary MGCs again. from the MGC with Error 406 Version Not Supported.
It is possible that the reply to a ServiceChange with Restart will be It is possible that the reply to a ServiceChange with Restart will be
lost, and a command will be received by the MG prior to the receipt of lost, and a command will be received by the MG prior to the receipt of
the ServiceChange response. The MG shall issue error 505 - Command the ServiceChange response. The MG shall issue error 505 - Command
Received before Restart Response. Received before Restart Response.
11.3. Negotiation of Protocol Version 11.3. Negotiation of Protocol Version
The first ServiceChange command from an MG shall contain the version The first ServiceChange command from an MG shall contain the version
number of the protocol supported by the MG in the ServiceChangeVersion number of the protocol supported by the MG in the ServiceChangeVersion
parameter. Upon receiving such a message, if the MGC supports only a parameter. Upon receiving such a message, if the MGC supports only a
lower version, then the MGC shall send a ServiceChangeReply with the lower version, then the MGC shall send a ServiceChangeReply with the
lower version and thereafter all the messages between MG and MGC shall lower version and thereafter all the messages between MG and MGC shall
conform to the lower version of the protocol. If the MG is unable to conform to the lower version of the protocol. If the MG is unable to
comply and it has established a transport connection to the MGC, it comply and it has established a transport connection to the MGC, it
should close that connection. In any event, it should reject all subse- should close that connection. In any event, it should reject all subse-
quent requests from the MGC with Error 406 Version Not Supported. quent requests from the MGC with Error 406 Version Not supported.
If the MGC supports a higher version than the MG but is able to support If the MGC supports a higher version than the MG but is able to support
the lower version proposed by the MG, it shall send a ServiceChangeReply the lower version proposed by the MG, it shall send a ServiceChangeReply
with the lower version and thereafter all the messages between MG and with the lower version and thereafter all the messages between MG and
MGC shall conform to the lower version of the protocol. If the MGC is MGC shall conform to the lower version of the protocol. If the MGC is
Internet draft MEGACO Protocol February 8, 2000
unable to comply, it shall reject the association, with Error 406 Ver- unable to comply, it shall reject the association, with Error 406 Ver-
sion Not Supported. sion Not Supported.
Protocol version negotiation may also occur at "handoff" and "failover" Protocol version negotiation may also occur at "handoff" and "failover"
ServiceChanges. ServiceChanges.
When extending the protocol with new versions, the following rules
should be followed.
Internet draft MEGACO Protocol February 21, 2000
1. Existing protocol elements, i.e., procedures, parameters, descrip-
tor, property, values, should not be changed unless a protocol
error needs to be corrected or it becomes necessary to change the
operation of the service that is being supported by the protocol.
2. The semantics of a command, a parameter, descriptor, property,
value should not be changed.
3. Established rules for formatting and encoding messages and parame-
ters should not be modified.
4. When information elements are found to be obsolete they can be
marked as not used. However, the identifier for that information
element will be marked as reserved. In that way it can not be used
in future versions.
11.4. Failure of an MG 11.4. Failure of an MG
If a MG fails, but is capable of sending a message to the MGC, it sends If a MG fails, but is capable of sending a message to the MGC, it sends
a ServiceChange with an appropriate method (graceful or forced) and a ServiceChange with an appropriate method (graceful or forced) and
specifies the Root TerminationID. When it returns to service, it sends specifies the Root TerminationID. When it returns to service, it sends
a ServiceChange with a "Restart" method. a ServiceChange with a "Restart" method.
Allowing the MGC to send duplicate messages to both MGs accommodates Allowing the MGC to send duplicate messages to both MGs accommodates
pairs of MGs that are capable of redundant failover of one of the MGs. pairs of MGs that are capable of redundant failover of one of the MGs.
Only the Working MG shall accept or reject transactions. Upon failover, Only the Working MG shall accept or reject transactions. Upon failover,
skipping to change at page 65, line 40 skipping to change at page 68, line 50
If the MG detects a failure of its controlling MGC, it attempts to con- If the MG detects a failure of its controlling MGC, it attempts to con-
tact the next MGC on its pre-provisioned list. It starts its attempts tact the next MGC on its pre-provisioned list. It starts its attempts
at the beginning (Primary MGC), unless that was the MGC that failed, in at the beginning (Primary MGC), unless that was the MGC that failed, in
which case it starts at its first Secondary MGC. It sends a Servi- which case it starts at its first Secondary MGC. It sends a Servi-
ceChange message with a "Failover" method and a "MGC Impending Failure" ceChange message with a "Failover" method and a "MGC Impending Failure"
reason. reason.
In partial failure, or manual maintenance reasons, an MGC may wish to In partial failure, or manual maintenance reasons, an MGC may wish to
direct its controlled MGs to use a different MGC. To do so, it sends a direct its controlled MGs to use a different MGC. To do so, it sends a
ServiceChange method to the MG with a "HandOff" method, and its desig- ServiceChange method to the MG with a "HandOff" method, and its desig-
nated replacement in ServiceChangeMGCId. The MG should send a Servi- nated replacement in ServiceChangeMgcId. The MG should send a Servi-
ceChange message with a "Handoff" method and a "MGC directed change" ceChange message with a "Handoff" method and a "MGC directed change"
reason to the designated MGC. If it fails to get a reply, or fails to reason to the designated MGC. If it fails to get a reply, or fails to
see an Audit command subsequently, it should behave as if its MGC see an Audit command subsequently, it should behave as if its MGC
failed, and start contacting secondary MGCs. If the MG is unable to failed, and start contacting secondary MGCs. If the MG is unable to
Internet draft MEGACO Protocol February 21, 2000
establish a control relationship with any MGC, it shall wait a random establish a control relationship with any MGC, it shall wait a random
amount of time as described in section 9.2 and then start contacting its amount of time as described in section 9.2 and then start contacting its
primary, and if necessary, its secondary MGCs again. primary, and if necessary, its secondary MGCs again.
No recommendation is made on how the MGCs involved in the Handoff main- No recommendation is made on how the MGCs involved in the Handoff main-
tain state information; this is considered to be out of scope of this tain state information; this is considered to be out of scope of this
recommendation. The MGC and MG may take the following steps when Handoff recommendation. The MGC and MG may take the following steps when Handoff
occurs. When the MGC initiates a HandOff, the handover should be tran- occurs. When the MGC initiates a HandOff, the handover should be tran-
sparent to Operations on the Media Gateway. Transactions can be exe- sparent to Operations on the Media Gateway. Transactions can be exe-
cuted in any order, and could be in progress when the ServiceChange is cuted in any order, and could be in progress when the ServiceChange is
Internet draft MEGACO Protocol February 8, 2000
executed. Accordingly, commands in progress continue, transaction executed. Accordingly, commands in progress continue, transaction
replies are sent to the new MGC (after a new control association is replies are sent to the new MGC (after a new control association is
established), and the MG should expect outstanding transaction replies established), and the MG should expect outstanding transaction replies
from the new MGC. No new messages shall be sent to the new MGC until from the new MGC. No new messages shall be sent to the new MGC until
the control association is established. Repeated transaction requests the control association is established. Repeated transaction requests
shall be directed to the new MGC. The MG shall maintain state on all shall be directed to the new MGC. The MG shall maintain state on all
terminations and contexts. terminations and contexts.
It is possible that the MGC could be implemented in such a way that a It is possible that the MGC could be implemented in such a way that a
failed MGC is replaced by a working MGC where the identity of the new failed MGC is replaced by a working MGC where the identity of the new
MGC is the same as the failed one. In such a case, ServiceChangeMGCId MGC is the same as the failed one. In such a case, ServiceChangeMgcId
would be specified with the previous value and the MG shall behave as if would be specified with the previous value and the MG shall behave as if
the value was changed, and send a ServiceChange message, as above. the value was changed, and send a ServiceChange message, as above.
Pairs of MGCs that are capable of redundant failover can notify the con- Pairs of MGCs that are capable of redundant failover can notify the con-
trolled MGs of the failover by the above mechanism. trolled MGs of the failover by the above mechanism.
12. PACKAGE DEFINITION 12. PACKAGE DEFINITION
The primary mechanism for extension is by means of Packages. Packages The primary mechanism for extension is by means of Packages. Packages
define additional Properties, Events, Signals and Statistics that may define additional Properties, Events, Signals and Statistics that may
occur on Terminations. occur on Terminations.
Packages defined by IETF will appear in separate RFCs. Packages defined by IETF will appear in separate RFCs.
Packages relevant to H.323 systems are listed in an Annex to Recommenda- Packages defined by ITU-T may appear in the relevant recommendations
tion H.323. (e.g. as annexes).
Packages defined by ITU-T will be described in Annexes to H.248.
1) A public document or a standard forum document, which can be refer- 1. A public document or a standard forum document, which can be refer-
enced as the document that describes the package following the enced as the document that describes the package following the
guideline above, should be specified. guideline above, should be specified.
2) The document shall specify the version of the Package that it 2. The document shall specify the version of the Package that it
describes. describes.
3) The document should be available on a public web server and should 3. The document should be available on a public web server and should
have a stable URL. The site should provide a mechanism to provide have a stable URL. The site should provide a mechanism to provide
comments and appropriate responses should be returned. comments and appropriate responses should be returned.
Internet draft MEGACO Protocol February 21, 2000
12.1. Guidelines for defining packages 12.1. Guidelines for defining packages
Packages define Properties, Events, Signals, and Statistics. Packages define Properties, Events, Signals, and Statistics.
Packages may also define new error codes according to the guidelines
given in section 13.2. This is a matter of documentary convenience: the
package documentation is submitted to IANA in support of the error code
registration. If a package is modified, it is unnecessary to provide
IANA with a new document reference in support of the error code unless
the description of the error code itself is modified.
Names of all such defined constructs shall consist of the PackageID Names of all such defined constructs shall consist of the PackageID
(which uniquely identifies the package) and the ID of the item (which (which uniquely identifies the package) and the ID of the item (which
uniquely identifies the item in that package). In the text encoding the uniquely identifies the item in that package). In the text encoding the
Internet draft MEGACO Protocol February 8, 2000
two shall be separated by a forward slash ("/") character. Example: two shall be separated by a forward slash ("/") character. Example:
togen/playtone is the text encoding to refer to the play tone signal in togen/playtone is the text encoding to refer to the play tone signal in
the tone generation package. the tone generation package.
A Package will contain the following sections: A Package will contain the following sections:
12.1.1. Package Overall description of the package, specifying: 12.1.1. Package
Package Name: only descriptive,
PackageID: Is an identifier Description: Overall description of the package, specifying:
Version: A new version of a package can only add additional Proper- Package Name: only descriptive,
ties, Events, Signals, Statistics and new possible values for an PackageID: Is an identifier
existing parameter described in the original package. No deletions Description:
or modifications shall be allowed. A version is an integer in the Version:
range from 1 to 99. A new version of a package can only add additional
Properties, Events, Signals, Statistics and new possible
values for an existing parameter described in the
package. No deletions or modifications shall be allowed.
A version is an integer in the range from 1 to 99.
Extends (Optional):
A package may extend an existing package. The version of
the original package must be specified. When a package
extends another package it shall only add additional
Properties, Events, Signals, Statistics and new possible
values for an existing parameter described in the original
package. An extended package shall not redefine or
overload a name defined in the original package.
Hence, if package B version 1 extends package A version 1,
version 2 of B will not be able to extend the A version 2
if A version 2 defines a name already in B version 1.
Extends (Optional): A package may extend an existing package. The Internet draft MEGACO Protocol February 21, 2000
version of the original package must be specified. When a package
extends another package it shall only add additional Properties,
Events, Signals, Statistics and new possible values for an existing
parameter described in the original package. An extended package
shall not redefine or overload a name defined in the original pack-
age. Hence, if package B version 1 extends package A version 1,
version 2 of B will not be able to extend the A version 2 if A ver-
sion 2 defines a name already in B version 1.
12.1.2. Properties 12.1.2. Properties
Properties defined by the package, specifying: Properties defined by the package, specifying:
Property Name: only descriptive. Property Name: only descriptive.
PropertyID: Is an identifier PropertyID: Is an identifier
Description: Description:
Type: One of: Type: One of:
String: UTF-8 string String: UTF-8 string
Integer: 4 byte signed integer Integer: 4 byte signed integer
Double: 8 byte signed integer Double: 8 byte signed integer
Character: Unicode UTF-8 encoding of a single letter. Character: Unicode UTF-8 encoding of a single letter.
Could be more than one octet. Could be more than one octet.
Enumeration: One of a list of possible unique values Enumeration: One of a list of possible unique values (See 12.3)
(See 12.3)
Sub-list: A list of several values from a list Sub-list: A list of several values from a list
Boolean Boolean
Possible Values: Possible Values:
Defined in: Which descriptor the property is defined in. Defined in:
Which descriptor the property is defined in. LocalControl
Internet draft MEGACO Protocol February 8, 2000 is for stream dependent properties. TerminationState is for
stream independent properties.
LocalControl is for stream dependent properties.
TerminationState is for stream independent properties.
Characteristics: Read / Write or both, and (optionally), global: Characteristics: Read / Write or both, and (optionally), global:
Indicates whether a property is read-only, or read-write, Indicates whether a property is read-only, or read-write,
and if it is global. If Global is omitted, the property and if it is global. If Global is omitted, the property
is not global. If a property is declared as global, is not global. If a property is declared as global,
the value of the property is shared by all terminations the value of the property is shared by all terminations
realizing the package. realizing the package.
12.1.3. Events 12.1.3. Events
Events defined by the package, specifying: Events defined by the package, specifying:
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Characteristics: Read / Write or both, and (optionally), global: Characteristics: Read / Write or both, and (optionally), global:
Indicates whether a property is read-only, or read-write, Indicates whether a property is read-only, or read-write,
and if it is global. If Global is omitted, the property and if it is global. If Global is omitted, the property
is not global. If a property is declared as global, is not global. If a property is declared as global,
the value of the property is shared by all terminations the value of the property is shared by all terminations
realizing the package. realizing the package.
12.1.3. Events 12.1.3. Events
Events defined by the package, specifying: Events defined by the package, specifying:
Event name: only descriptive. Event name: only descriptive.
EventID: Is an identifier EventID: Is an identifier
Description: Description:
EventsDescriptor Parameters: EventsDescriptor Parameters:
Parameters used by the MGC to configure the event, Parameters used by the MGC to configure the event,
and found in the EventsDescriptor. See section 12.2 and found in the EventsDescriptor. See section 12.2.
ObservedEventsDescriptor Parameters: ObservedEventsDescriptor Parameters:
Parameters returned to the MGC in Notify requests Parameters returned to the MGC in Notify requests and in
and in replies to command requests from the MGC that replies to command requests from the MGC that audit
audit ObservedEventsDescriptor, and found in the ObservedEventsDescriptor, and found in the
ObservedEventsDescriptor. See section 12.2 ObservedEventsDescriptor. See section 12.2.
Internet draft MEGACO Protocol February 21, 2000
12.1.4. Signals 12.1.4. Signals
Signals defined by the package, specifying: Signals defined by the package, specifying:
Signal Name: only descriptive. Signal Name: only descriptive.
SignalID: Is an identifier. SignalID is used in a SignalID: Is an identifier. SignalID is used in a
SignalsDescriptor SignalsDescriptor
Description Description
SignalType: One of: SignalType: One of:
OO (On/Off) OO (On/Off)
TO (TimeOut) TO (TimeOut)
BR (Brief) BR (Brief)
Note: SignalType may be defined such that it is dependent on the value Note:SignalType may be defined such that it is dependent on the
of one or more parameters. Signals that would be played with SignalType value of one or more parameters. Signals that would be played
BR should have a default duration. The package has to define the default with SignalType BR should have a default duration. The package has
duration and signalType. to define the default duration and signalType.
Duration: in hundredths of seconds Duration: in hundredths of seconds
Additional Parameters: See section 12.2 Additional Parameters: See section 12.2
Internet draft MEGACO Protocol February 8, 2000
12.1.5. Statistics 12.1.5. Statistics
Statistics defined by the package, specifying: Statistics defined by the package, specifying:
Statistic name: only descriptive. Statistic name: only descriptive.
StatisticID: Is an identifier StatisticID: Is an identifier
StatisticID is used in a StatisticsDescriptor StatisticID is used in a StatisticsDescriptor
Description Description
Units: unit of measure, e.g. milliseconds, packets Units: unit of measure, e.g. milliseconds, packets
12.1.6. Procedures 12.1.6. Procedures
Additional guidance on the use of the package. Additional guidance on the use of the package.
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12.2. Guidelines to defining Properties, Statistics and Parameters to 12.2. Guidelines to defining Properties, Statistics and Parameters to
Events and Signals. Events and Signals.
Parameter Name: only descriptive Parameter Name: only descriptive
ParameterID: Is an identifier ParameterID: Is an identifier
Type: One of: Type: One of:
String: UTF-8 octet string String: UTF-8 octet string
Integer: 4 octet signed integer Integer: 4 octet signed integer
Double: 8 octet signed integer Double: 8 octet signed integer
Character: Unicode UTF-8 encoding of a single letter. Character: Unicode UTF-8 encoding of a single letter.
Internet draft MEGACO Protocol February 21, 2000
Could be more than one octet. Could be more than one octet.
Enumeration: One of a list of possible unique Enumeration: One of a list of possible unique values
values (See 12.3) (See 12.3)
Sub-list: A list of several values from a list Sub-list: A list of several values from a list
Boolean Boolean
Possible values: Possible values:
Description: Description:
12.3. Lists 12.3. Lists
Possible values for parameters include enumerations. Enumerations may Possible values for parameters include enumerations. Enumerations may
be defined in a list. It is recommended that the list be IANA be defined in a list. It is recommended that the list be IANA
registered so that packages that extend the list can be defined without registered so that packages that extend the list can be defined without
concern for conflicting names. concern for conflicting names.
12.4. Identifiers 12.4. Identifiers
Identifiers in text encoding shall be strings of up to 64 characters, Identifiers in text encoding shall be strings of up to 64 characters,
containing no spaces, starting with an alphanumeric character and con- containing no spaces, starting with an alphanumeric character and con-
sisting of alphanumeric characters and / or digits, and possibly includ- sisting of alphanumeric characters and / or digits, and possibly includ-
ing the special character underscore ("_"). Identifiers in binary ing the special character underscore ("_"). Identifiers in binary
encoding are 2 octets long. Both text and binary values shall be speci- encoding are 2 octets long. Both text and binary values shall be speci-
fied for each identifier, including identifiers used as values in fied for each identifier, including identifiers used as values in
Internet draft MEGACO Protocol February 8, 2000
enumerated types. enumerated types.
12.5. Package Registration 12.5. Package Registration
A package can be registered with IANA for interoperability reasons. See A package can be registered with IANA for interoperability reasons. See
section 13 for IANA considerations. section 13 for IANA considerations.
13. IANA CONSIDERATIONS 13. IANA CONSIDERATIONS
13.1. Packages 13.1. Packages
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1. A unique string name, unique serial number and version number is 1. A unique string name, unique serial number and version number is
registered for each package. The string name is used with text registered for each package. The string name is used with text
encoding. The serial number shall be used with binary encoding. encoding. The serial number shall be used with binary encoding.
Serial Numbers 60000-64565 are reserved for private use. Serial Serial Numbers 60000-64565 are reserved for private use. Serial
number 0 is reserved. number 0 is reserved.
2. A contact name, email and postal addresses for that contact shall 2. A contact name, email and postal addresses for that contact shall
be specified. The contact information shall be updated by the be specified. The contact information shall be updated by the
defining organization as necessary. defining organization as necessary.
Internet draft MEGACO Protocol February 21, 2000
3. A reference to a document that describes the package, which should 3. A reference to a document that describes the package, which should
be public: The document shall specify the version of the Package be public: The document shall specify the version of the Package
that it describes. If the document is public, it should be located that it describes. If the document is public, it should be located
on a public web server and should have a stable URL. The site on a public web server and should have a stable URL. The site
should provide a mechanism to provide comments and appropriate should provide a mechanism to provide comments and appropriate
responses should be returned. responses should be returned.
4. Packages registered by other than recognized standards bodies shall 4. Packages registered by other than recognized standards bodies shall
have a minimum package name length of 8 characters have a minimum package name length of 8 characters
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The following considerations SHALL be met to register an error code with The following considerations SHALL be met to register an error code with
IANA: IANA:
1. An error number and a one line (80 character maximum) string is 1. An error number and a one line (80 character maximum) string is
registered for each error. registered for each error.
2. A complete description of the conditions under which the error is 2. A complete description of the conditions under which the error is
detected shall be included in a publicly available document. The detected shall be included in a publicly available document. The
description shall be sufficiently clear to differentiate the error description shall be sufficiently clear to differentiate the error
Internet draft MEGACO Protocol February 8, 2000
from all other existing error codes. from all other existing error codes.
3. The document should be available on a public web server and should 3. The document should be available on a public web server and should
have a stable URL. have a stable URL.
4. Error numbers registered by recognized standards bodies shall have 4. Error numbers registered by recognized standards bodies shall have
3 or 4 character error numbers. 3 or 4 character error numbers.
5. Error numbers registered by all other organizations or individuals 5. Error numbers registered by all other organizations or individuals
shall have 4 character error numbers. shall have 4 character error numbers.
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13.3. ServiceChange Reasons 13.3. ServiceChange Reasons
The following considerations SHALL be met to register service change The following considerations SHALL be met to register service change
reason with IANA: reason with IANA:
1. A one phrase, 80-character maximum, unique reason code is 1. A one phrase, 80-character maximum, unique reason code is
registered for each reason. registered for each reason.
2. A complete description of the conditions under which the reason is 2. A complete description of the conditions under which the reason is
Internet draft MEGACO Protocol February 21, 2000
used is detected shall be included in a publicly available docu- used is detected shall be included in a publicly available docu-
ment. The description shall be sufficiently clear to differentiate ment. The description shall be sufficiently clear to differentiate
the reason from all other existing reasons. the reason from all other existing reasons.
3. The document should be available on a public web server and should 3. The document should be available on a public web server and should
have a stable URL. have a stable URL.
14. CONTACT INFORMATION 14. CONTACT INFORMATION
IETF Editor IETF Editor
skipping to change at page 71, line 48 skipping to change at page 75, line 24
14. CONTACT INFORMATION 14. CONTACT INFORMATION
IETF Editor IETF Editor
Brian Rosen Brian Rosen
Marconi Marconi
1000 FORE Drive 1000 FORE Drive
Warrendale, PA 15086 Warrendale, PA 15086
U.S.A. U.S.A.
Phone: +1 724-742-6826 Phone: +1 724-742-6826
Email: brosen@fore.com Email: brosen@fore.com
ITU Editor ITU Editor
John Segers John Segers
Lucent Technologies Lucent Technologies
Room HE 306 Room HE 306
Dept. Forward Looking Work Dept. Forward Looking Work
P.O. Box 18, 1270 AA Huizen P.O. Box 18, 1270 AA Huizen
Internet draft MEGACO Protocol February 8, 2000
Netherlands Netherlands
Phone: +31 35 687 4724 Phone: +31 35 687 4724
Email: jsegers@lucent.com Email: jsegers@lucent.com
Additional IETF Authors Additional IETF Authors
Fernando Cuervo Fernando Cuervo
Nortel Networks Nortel Networks
P.O. Box 3511 Stn C Ottawa, ON, K1Y 4H7 P.O. Box 3511 Stn C Ottawa, ON, K1Y 4H7
Canada Canada
Email: cuervo@nortelnetworks.com Email: cuervo@nortelnetworks.com
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USA USA
Phone: +1 978-263-6890 Phone: +1 978-263-6890
Email: bhill@gothamnetworks.com Email: bhill@gothamnetworks.com
Christian Huitema Christian Huitema
Telcordia Technologies Telcordia Technologies
MCC 1J236B MCC 1J236B
445 South Street 445 South Street
Morristown, NJ 07960 Morristown, NJ 07960
U.S.A. U.S.A.
Internet draft MEGACO Protocol February 21, 2000
Phone: +1 973-829-4266 Phone: +1 973-829-4266
EMail: huitema@research.telcordia.com EMail: huitema@research.telcordia.com
Nancy Greene Nancy Greene
Nortel Networks Nortel Networks
P.O. Box 3511 Stn C P.O. Box 3511 Stn C
Ottawa, ON, K1Y 4H7 Ottawa, ON, K1Y 4H7
Canada Canada
Phone: +1 514-271-7221 Phone: +1 514-271-7221
Email: ngreene@nortelnetworks.com Email: ngreene@nortelnetworks.com
Abdallah Rayhan Abdallah Rayhan
Nortel Networks Nortel Networks
P.O. Box 3511 Stn C P.O. Box 3511 Stn C
Ottawa, ON, K1Y 4H7 Ottawa, ON, K1Y 4H7
Canada Canada
Phone: +1 613-763-9611 Phone: +1 613-763-9611
Email: arayhan@nortelnetworks.com Email: arayhan@nortelnetworks.com
Internet draft MEGACO Protocol February 8, 2000
ANNEX A BINARY ENCODING OF THE PROTOCOL (NORMATIVE) ANNEX A BINARY ENCODING OF THE PROTOCOL (NORMATIVE)
This Annex specifies the syntax of messages using the notation defined This Annex specifies the syntax of messages using the notation defined
in ASN.1 [ITU-T Recommendation X.680 (1997): Information Technology - in ASN.1 [ITU-T Recommendation X.680 (1997): Information Technology -
Abstract Syntax Notation One (ASN.1) - Specification of basic nota- Abstract Syntax Notation One (ASN.1) - Specification of basic nota-
tion.]. Messages shall be encoded for transmission by applying the basic tion.]. Messages shall be encoded for transmission by applying the basic
encoding rules specified in [ITU-T Recommendation X.690(1994) Informa- encoding rules specified in [ITU-T Recommendation X.690(1994) Informa-
tion Technology - ASN.1 Encoding Rules: Specification of Basic tion Technology - ASN.1 Encoding Rules: Specification of Basic
Encoding Rules (BER)]. Encoding Rules (BER)].
skipping to change at page 73, line 34 skipping to change at page 77, line 4
the group and a circuit. Wildcarding must be possible at all levels. the group and a circuit. Wildcarding must be possible at all levels.
The following paragraphs explain how this is achieved. The following paragraphs explain how this is achieved.
The ASN.1 description uses octet strings of up to 8 octets in length for The ASN.1 description uses octet strings of up to 8 octets in length for
Termination IDs. This means that Termination IDs consist of at most 64 Termination IDs. This means that Termination IDs consist of at most 64
bits. A fully specified Termination ID may be preceded by a sequence of bits. A fully specified Termination ID may be preceded by a sequence of
wildcarding fields. A wildcarding field is octet in length. Bit 7 (the wildcarding fields. A wildcarding field is octet in length. Bit 7 (the
most significant bit) of this octet specifies what type of wildcarding most significant bit) of this octet specifies what type of wildcarding
is invoked: if the bit value equals 1, then the ALL wildcard is used; is invoked: if the bit value equals 1, then the ALL wildcard is used;
if the bit value if 0, then the CHOOSE wildcard is used. Bit 6 of the if the bit value if 0, then the CHOOSE wildcard is used. Bit 6 of the
Internet draft MEGACO Protocol February 21, 2000
wildcarding field specifies whether the wildcarding pertains to one wildcarding field specifies whether the wildcarding pertains to one
level in the hierarchical naming scheme (bit value 0) or to the level of level in the hierarchical naming scheme (bit value 0) or to the level of
the hierarchy specified in the wildcarding field plus all lower levels the hierarchy specified in the wildcarding field plus all lower levels
(bit value 1). Bits 0 through 5 of the wildcarding field specify the (bit value 1). Bits 0 through 5 of the wildcarding field specify the
bit position in the Termination ID at which the starts. bit position in the Termination ID at which the starts.
We illustrate this scheme with some examples. Assume that Termination We illustrate this scheme with some examples. In these examples, the
IDs are three octets long and that each octet represents a level in a most significant bit in a string of bits appears on the left hand side.
hierarchical naming scheme. A valid Termination ID is
Assume that Termination IDs are three octets long and that each octet
represents a level in a hierarchical naming scheme. A valid Termination
ID is
00000001 00011110 01010101. 00000001 00011110 01010101.
Addressing ALL names with prefix 00000001 00011110 is done as follows: Addressing ALL names with prefix 00000001 00011110 is done as follows:
wildcarding field: 10000111 wildcarding field: 10000111
Termination ID: 00000001 00011110 xxxxxxxx. Termination ID: 00000001 00011110 xxxxxxxx.
The values of the bits labeled "x" is irrelevant and shall be ignored by The values of the bits labeled "x" is irrelevant and shall be ignored by
the receiver. the receiver.
Internet draft MEGACO Protocol February 8, 2000
Indicating to the receiver that is must choose a name with 00011110 as Indicating to the receiver that is must choose a name with 00011110 as
the second octet is done as follows: the second octet is done as follows:
wildcarding fields: 00010111 followed by 00000111 wildcarding fields: 00010111 followed by 00000111
Termination ID: xxxxxxxx 00011110 xxxxxxxx.
The first wildcard field indicates a CHOOSE wildcard for the level in Termination ID: xxxxxxxx 00011110 xxxxxxxx. The first wild-
the naming hierarchy starting at bit 23, the highest level in our card field indicates a CHOOSE wildcard for the level in the naming
assumed naming scheme. The second wildcard field indicates a CHOOSE hierarchy starting at bit 23, the highest level in our assumed nam-
wildcard for the level in the naming hierarchy starting at bit 7, the ing scheme. The second wildcard field indicates a CHOOSE wildcard
lowest level in our assumed naming scheme. for the level in the naming hierarchy starting at bit 7, the lowest
level in our assumed naming scheme.
Finally, a CHOOSE-wildcarded name with the highest level of the name Finally, a CHOOSE-wildcarded name with the highest level of the name
equal to 00000001 is specified as follows: equal to 00000001 is specified as follows:
wildcard field: 01001111 wildcard field: 01001111
Termination ID: 0000001 xxxxxxxx xxxxxxxx . Termination ID: 0000001 xxxxxxxx xxxxxxxx .
Bit value 1 at bit position 6 of the first octet of the wildcard field Bit value 1 at bit position 6 of the first octet of the wildcard field
indicates that the wildcarding pertains to the specified level in the indicates that the wildcarding pertains to the specified level in the
naming hierarchy and all lower levels. naming hierarchy and all lower levels.
Context IDs may also be wildcarded. In the case of Context IDs, how- Context IDs may also be wildcarded. In the case of Context IDs,
ever, specifying partial names is not allowed. Context ID 0x0 SHALL be
used to indicate the NULL Context, Context ID 0xFFFFFFFE SHALL be used Internet draft MEGACO Protocol February 21, 2000
to indicate a CHOOSE wildcard, and Context ID 0xFFFFFFFF SHALL be used
to indicate an ALL wildcard. however, specifying partial names is not allowed. Context ID 0x0 SHALL
be used to indicate the NULL Context, Context ID 0xFFFFFFFE SHALL be
used to indicate a CHOOSE wildcard, and Context ID 0xFFFFFFFF SHALL be
used to indicate an ALL wildcard.
TerminationID 0xFFFFFFFFFFFFFFFF SHALL be used to indicate the ROOT Ter- TerminationID 0xFFFFFFFFFFFFFFFF SHALL be used to indicate the ROOT Ter-
mination. mination.
A.2. ASN.1 syntax specification A.2. ASN.1 syntax specification
This section contains the ASN.1 specification of the H.248 protocol syn- This section contains the ASN.1 specification of the H.248 protocol syn-
tax. tax.
NOTE - In case a transport mechanism is used that employs application NOTE In case a transport mechanism is used that employs application
level framing, the definition of Transaction below changes. Refer to level framing, the definition of Transaction below changes. Refer
the annex defining the transport mechanism for the definition that to the annex defining the transport mechanism for the definition
applies in that case. that applies in that case.
NOTE - The ASN.1 specification below contains a clause defining Termina-
tionIDList as a sequence of TerminationIDs. The length of this sequence
SHALL be one. The SEQUENCE OF construct is present only to allow future
extensions.
Internet draft MEGACO Protocol February 8, 2000 NOTE The ASN.1 specification below contains a clause defining Termina-
tionIDList as a sequence of TerminationIDs. The length of this
sequence SHALL be one. The SEQUENCE OF construct is present only
to allow future extensions.
MEDIA-GATEWAY-CONTROL DEFINITIONS AUTOMATIC TAGS::= MEDIA-GATEWAY-CONTROL DEFINITIONS AUTOMATIC TAGS::=
BEGIN BEGIN
MegacoMessage ::= SEQUENCE MegacoMessage ::= SEQUENCE
{ {
authHeader AuthenticationHeader OPTIONAL, authHeader AuthenticationHeader OPTIONAL,
mess Message mess Message
} }
skipping to change at page 75, line 30 skipping to change at page 79, line 4
ad AuthData ad AuthData
} }
SecurityParmIndex ::= OCTET STRING(SIZE(4)) SecurityParmIndex ::= OCTET STRING(SIZE(4))
SequenceNum ::= OCTET STRING(SIZE(4)) SequenceNum ::= OCTET STRING(SIZE(4))
AuthData ::= OCTET STRING (SIZE (16..32)) AuthData ::= OCTET STRING (SIZE (16..32))
Message ::= SEQUENCE Message ::= SEQUENCE
Internet draft MEGACO Protocol February 21, 2000
{ {
version INTEGER(0..99), version INTEGER(0..99),
-- The version of the protocol defined here is equal to 1.
mId MId, -- Name/address of message originator mId MId, -- Name/address of message originator
messageBody CHOICE messageBody CHOICE
{ {
messageError ErrorDescriptor, messageError ErrorDescriptor,
transactions SEQUENCE OF Transaction transactions SEQUENCE OF Transaction
}, },
... ...
} }
MId ::= CHOICE MId ::= CHOICE
{ {
ip4Address IP4Address, ip4Address IP4Address,
ip6Address IP6Address, ip6Address IP6Address,
domainName DomainName, domainName DomainName,
deviceName PathName, deviceName PathName,
mtpAddress OCTET STRING(SIZE(5)), mtpAddressOCTET STRING(SIZE(2)),
-- Addressing structure of mtpAddress: -- Addressing structure of mtpAddress:
-- 15 0 -- 15 0
-- | PC | NI | -- | PC | NI |
-- 14 bits 2 bits -- 14 bits 2 bits
... ...
} }
Internet draft MEGACO Protocol February 8, 2000
DomainName ::= SEQUENCE DomainName ::= SEQUENCE
{ {
name IA5String, name IA5String,
-- The name starts with an alphanumeric digit followed by a -- The name starts with an alphanumeric digit followed by a
-- sequence of alphanumeric digits, hyphens and dots. No two -- sequence of alphanumeric digits, hyphens and dots. No two
-- dots shall occur consecutively. -- dots shall occur consecutively.
portNumber INTEGER(0..65535) OPTIONAL portNumber INTEGER(0..65535) OPTIONAL
} }
IP4Address ::= SEQUENCE IP4Address ::= SEQUENCE
skipping to change at page 76, line 29 skipping to change at page 80, line 4
portNumber INTEGER(0..65535) OPTIONAL portNumber INTEGER(0..65535) OPTIONAL
} }
IP6Address ::= SEQUENCE IP6Address ::= SEQUENCE
{ {
address OCTET STRING (SIZE(16)), address OCTET STRING (SIZE(16)),
portNumber INTEGER(0..65535) OPTIONAL portNumber INTEGER(0..65535) OPTIONAL
} }
PathName ::= IA5String(SIZE (1..64)) PathName ::= IA5String(SIZE (1..64))
Internet draft MEGACO Protocol February 21, 2000
-- See section A.3 -- See section A.3
Transaction ::= CHOICE Transaction ::= CHOICE
{ {
transactionRequest TransactionRequest, transactionRequest TransactionRequest,
transactionPending TransactionPending, transactionPending TransactionPending,
transactionReply TransactionReply, transactionReply TransactionReply,
transactionResponseAckTransactionResponseAck,
-- use of response acks is dependent on underlying transport
... ...
} }
TransactionId ::= INTEGER(0..4294967295) -- 32 bit unsigned integer TransactionId ::= INTEGER(0..4294967295) -- 32 bit unsigned integer
TransactionRequest ::= SEQUENCE TransactionRequest ::= SEQUENCE
{ {
transactionId TransactionId, transactionId TransactionId,
actions SEQUENCE OF ActionRequest, actions SEQUENCE OF ActionRequest,
... ...
} }
TransactionPending ::= SEQUENCE TransactionPending ::= SEQUENCE
{ {
transactionId TransactionId, transactionId TransactionId,
... ...
} }
TransactionReply ::= SEQUENCE TransactionReply ::= SEQUENCE
Internet draft MEGACO Protocol February 8, 2000
{ {
transactionId TransactionId, transactionId TransactionId,
transactionResult CHOICE transactionResult CHOICE
{ {
transactionError ErrorDescriptor, transactionError ErrorDescriptor,
actionReplies SEQUENCE OF ActionReply actionReplies SEQUENCE OF ActionReply
}, },
... ...
} }
TransactionResponseAck ::= SEQUENCE
{
firstAckTransactionId,
lastAckTransactionId OPTIONAL
}
ErrorDescriptor ::= SEQUENCE ErrorDescriptor ::= SEQUENCE
{ {
errorCode ErrorCode, errorCode ErrorCode,
errorText ErrorText OPTIONAL errorText ErrorText OPTIONAL
Internet draft MEGACO Protocol February 21, 2000
} }
ErrorCode ::= INTEGER(0..65535) ErrorCode ::= INTEGER(0..65535)
-- See section 13 for IANA considerations w.r.t. error codes -- See section 13 for IANA considerations w.r.t. error codes
ErrorText ::= IA5String ErrorText ::= IA5String
ContextID ::= INTEGER(0..4294967295) ContextID ::= INTEGER(0..4294967295)
-- Context NULL Value: 0 -- Context NULL Value: 0
skipping to change at page 78, line 4 skipping to change at page 81, line 39
{ {
contextId ContextID, contextId ContextID,
errorDescriptor ErrorDescriptor OPTIONAL, errorDescriptor ErrorDescriptor OPTIONAL,
contextReply ContextRequest OPTIONAL, contextReply ContextRequest OPTIONAL,
commandReply SEQUENCE OF CommandReply commandReply SEQUENCE OF CommandReply
} }
ContextRequest ::= SEQUENCE ContextRequest ::= SEQUENCE
{ {
priority INTEGER(0..15) OPTIONAL, priority INTEGER(0..15) OPTIONAL,
Internet draft MEGACO Protocol February 8, 2000
emergency BOOLEAN OPTIONAL, emergency BOOLEAN OPTIONAL,
topologyReq SEQUENCE OF TopologyRequest OPTIONAL, topologyReq SEQUENCE OF TopologyRequest OPTIONAL,
... ...
} }
ContextAttrAuditRequest ::= SEQUENCE ContextAttrAuditRequest ::= SEQUENCE
{ {
topology NULL OPTIONAL, topology NULL OPTIONAL,
emergency NULL OPTIONAL, emergency NULL OPTIONAL,
priority NULL OPTIONAL, priority NULL OPTIONAL,
... ...
} }
CommandRequest ::= SEQUENCE CommandRequest ::= SEQUENCE
{ {
Internet draft MEGACO Protocol February 21, 2000
command Command, command Command,
optional NULL OPTIONAL, optional NULL OPTIONAL,
wildcardReturn NULL OPTIONAL, wildcardReturn NULL OPTIONAL,
... ...
} }
Command ::= CHOICE Command ::= CHOICE
{ {
addReq AmmRequest, addReq AmmRequest,
moveReq AmmRequest, moveReq AmmRequest,
skipping to change at page 79, line 5 skipping to change at page 82, line 41
modReply AmmsReply, modReply AmmsReply,
subtractReply AmmsReply, subtractReply AmmsReply,
-- Add, Move, Modify, Subtract replies have the same parameters -- Add, Move, Modify, Subtract replies have the same parameters
auditCapReply AuditReply, auditCapReply AuditReply,
auditValueReply AuditReply, auditValueReply AuditReply,
notifyReply NotifyReply, notifyReply NotifyReply,
serviceChangeReply ServiceChangeReply, serviceChangeReply ServiceChangeReply,
... ...
} }
Internet draft MEGACO Protocol February 8, 2000
TopologyRequest ::= SEQUENCE TopologyRequest ::= SEQUENCE
{ {
terminationFrom TerminationID, terminationFrom TerminationID,
terminationTo TerminationID, terminationTo TerminationID,
topologyDirection ENUMERATED topologyDirection ENUMERATED
{ {
bothway(0), bothway(0),
isolate(1), isolate(1),
oneway(2) oneway(2)
} }
} }
AmmRequest ::= SEQUENCE AmmRequest ::= SEQUENCE
{ {
Internet draft MEGACO Protocol February 21, 2000
terminationID TerminationIDList, terminationID TerminationIDList,
mediaDescriptor MediaDescriptor OPTIONAL, mediaDescriptor MediaDescriptor OPTIONAL,
modemDescriptor ModemDescriptor OPTIONAL, modemDescriptor ModemDescriptor OPTIONAL,
muxDescriptor MuxDescriptor OPTIONAL, muxDescriptor MuxDescriptor OPTIONAL,
eventsDescriptor EventsDescriptor OPTIONAL, eventsDescriptor EventsDescriptor OPTIONAL,
eventBufferDescriptor EventBufferDescriptor OPTIONAL, eventBufferDescriptor EventBufferDescriptor OPTIONAL,
signalsDescriptor SignalsDescriptor OPTIONAL, signalsDescriptor SignalsDescriptor OPTIONAL,
digitMapDescriptor DigitMapDescriptor OPTIONAL, digitMapDescriptor DigitMapDescriptor OPTIONAL,
auditDescriptor AuditDescriptor OPTIONAL, auditDescriptor AuditDescriptor OPTIONAL,
... ...
skipping to change at page 79, line 42 skipping to change at page 83, line 28
AmmsReply ::= SEQUENCE AmmsReply ::= SEQUENCE
{ {
terminationID TerminationIDList, terminationID TerminationIDList,
terminationAudit TerminationAudit OPTIONAL terminationAudit TerminationAudit OPTIONAL
} }
SubtractRequest ::= SEQUENCE SubtractRequest ::= SEQUENCE
{ {
terminationID TerminationIDList, terminationID TerminationIDList,
auditDescriptor AuditDescriptor OPTIONAL auditDescriptor AuditDescriptor OPTIONAL,
...
} }
AuditRequest ::= SEQUENCE AuditRequest ::= SEQUENCE
{ {
terminationID TerminationID, terminationID TerminationID,
auditDescriptor AuditDescriptor auditDescriptorAuditDescriptor,
...
} }
AuditReply ::= SEQUENCE AuditReply ::= SEQUENCE
{ {
terminationID TerminationID, terminationID TerminationID,
auditResult AuditResult auditResult AuditResult
Internet draft MEGACO Protocol February 8, 2000
} }
AuditResult ::= CHOICE AuditResult ::= CHOICE
{ {
contextAuditResult TerminationIDList, contextAuditResult TerminationIDList,
terminationAuditResult TerminationAudit terminationAuditResult TerminationAudit
} }
AuditDescriptor ::= SEQUENCE AuditDescriptor ::= SEQUENCE
{ {
Internet draft MEGACO Protocol February 21, 2000
auditToken BIT STRING auditToken BIT STRING
{ {
muxToken(0), modemToken(1), mediaToken(2), muxToken(0), modemToken(1), mediaToken(2),
eventsToken(3), signalsToken(4), eventsToken(3), signalsToken(4),
digitMapToken(5), statsToken(6), digitMapToken(5), statsToken(6),
observedEventsToken(7), observedEventsToken(7),
packagesToken(8), eventBufferToken(9) packagesToken(8), eventBufferToken(9)
} OPTIONAL, } OPTIONAL,
... ...
} }
skipping to change at page 80, line 50 skipping to change at page 84, line 40
observedEventsDescriptor ObservedEventsDescriptor, observedEventsDescriptor ObservedEventsDescriptor,
statisticsDescriptor StatisticsDescriptor, statisticsDescriptor StatisticsDescriptor,
packagesDescriptor PackagesDescriptor, packagesDescriptor PackagesDescriptor,
... ...
} }
NotifyRequest ::= SEQUENCE NotifyRequest ::= SEQUENCE
{ {
terminationID TerminationIDList, terminationID TerminationIDList,
observedEventsDescriptor ObservedEventsDescriptor, observedEventsDescriptor ObservedEventsDescriptor,
errorDescriptor ErrorDescriptor OPTIONAL errorDescriptorErrorDescriptor OPTIONAL,
...
} }
Internet draft MEGACO Protocol February 8, 2000
NotifyReply ::= SEQUENCE NotifyReply ::= SEQUENCE
{ {
terminationID TerminationIDList OPTIONAL, terminationID TerminationIDList OPTIONAL,
errorDescriptor ErrorDescriptor OPTIONAL errorDescriptor ErrorDescriptor OPTIONAL,
...
} }
ObservedEventsDescriptor ::= SEQUENCE ObservedEventsDescriptor ::= SEQUENCE
{ {
requestId RequestID, requestId RequestID,
observedEventLst SEQUENCE OF ObservedEvent observedEventLst SEQUENCE OF ObservedEvent
Internet draft MEGACO Protocol February 21, 2000
} }
ObservedEvent ::= SEQUENCE ObservedEvent ::= SEQUENCE
{ {
eventName EventName, eventName EventName,
streamID StreamID OPTIONAL, streamID StreamID OPTIONAL,
eventParList SEQUENCE OF EventParameter, eventParList SEQUENCE OF EventParameter,
timeNotation TimeNotation OPTIONAL timeNotation TimeNotation OPTIONAL
} }
skipping to change at page 81, line 38 skipping to change at page 85, line 28
EventParameter ::= SEQUENCE EventParameter ::= SEQUENCE
{ {
eventParameterName Name, eventParameterName Name,
value Value value Value
} }
ServiceChangeRequest ::= SEQUENCE ServiceChangeRequest ::= SEQUENCE
{ {
terminationID TerminationIDList, terminationID TerminationIDList,
serviceChangeParms ServiceChangeParm serviceChangeParms ServiceChangeParm,
...
} }
ServiceChangeReply ::= SEQUENCE ServiceChangeReply ::= SEQUENCE
{ {
terminationID TerminationIDList, terminationID TerminationIDList,
serviceChangeResult ServiceChangeResult serviceChangeResult ServiceChangeResult,
...
} }
-- For ServiceChangeResult, no parameters are mandatory. Hence the -- For ServiceChangeResult, no parameters are mandatory. Hence the
-- distinction between ServiceChangeParm and ServiceChangeResParm. -- distinction between ServiceChangeParm and ServiceChangeResParm.
ServiceChangeResult ::= CHOICE ServiceChangeResult ::= CHOICE
{ {
errorDescriptor ErrorDescriptor, errorDescriptor ErrorDescriptor,
serviceChangeResParms ServiceChangeResParm serviceChangeResParms ServiceChangeResParm
} }
Internet draft MEGACO Protocol February 8, 2000
WildcardField ::= OCTET STRING(SIZE(1)) WildcardField ::= OCTET STRING(SIZE(1))
TerminationID ::= SEQUENCE TerminationID ::= SEQUENCE
{ {
wildcard SEQUENCE OF WildcardField, wildcard SEQUENCE OF WildcardField,
id OCTET STRING(SIZE(1..8)) id OCTET STRING(SIZE(1..8))
} }
Internet draft MEGACO Protocol February 21, 2000
-- See Section A.1 for explanation of wildcarding mechanism. -- See Section A.1 for explanation of wildcarding mechanism.
-- Termination ID 0xFFFFFFFFFFFFFFFF indicates the ROOT Termination. -- Termination ID 0xFFFFFFFFFFFFFFFF indicates the ROOT Termination.
TerminationIDList ::= SEQUENCE OF TerminationID TerminationIDList ::= SEQUENCE OF TerminationID
MediaDescriptor ::= SEQUENCE MediaDescriptor ::= SEQUENCE
{ {
termStateDescr TerminationStateDescriptor OPTIONAL, termStateDescr TerminationStateDescriptor OPTIONAL,
streams CHOICE streams CHOICE
skipping to change at page 83, line 4 skipping to change at page 86, line 48
LocalControlDescriptor ::= SEQUENCE LocalControlDescriptor ::= SEQUENCE
{ {
streamMode StreamMode OPTIONAL, streamMode StreamMode OPTIONAL,
reserve BOOLEAN, reserve BOOLEAN,
propertyParms SEQUENCE OF PropertyParm, propertyParms SEQUENCE OF PropertyParm,
... ...
} }
StreamMode ::= ENUMERATED StreamMode ::= ENUMERATED
{ {
Internet draft MEGACO Protocol February 8, 2000
sendOnly(0), sendOnly(0),
recvOnly(1), recvOnly(1),
sendRecv(2), sendRecv(2),
inactive(3), inactive(3),
loopBack(4), loopBack(4),
... ...
} }
Internet draft MEGACO Protocol February 21, 2000
-- In PropertyParm, value is a SEQUENCE OF octet string. When sent -- In PropertyParm, value is a SEQUENCE OF octet string. When sent
-- by an MGC the interpretation is as follows: -- by an MGC the interpretation is as follows:
-- empty sequence means CHOOSE -- empty sequence means CHOOSE
-- one element sequence specifies value -- one element sequence specifies value
-- longer sequence means "choose one of the values" -- longer sequence means "choose one of the values"
-- The relation field may only be selected if the value sequence -- The relation field may only be selected if the value sequence
-- has length 1. It indicates that the MG has to choose a value -- has length 1. It indicates that the MG has to choose a value
-- for the property. E.g., x > 3 (using the greaterThan -- for the property. E.g., x > 3 (using the greaterThan
-- value for relation) instructs the MG to choose any value larger -- value for relation) instructs the MG to choose any value larger
-- than 3 for property x. -- than 3 for property x.
skipping to change at page 83, line 50 skipping to change at page 87, line 42
range BOOLEAN range BOOLEAN
} OPTIONAL } OPTIONAL
} }
Name ::= OCTET STRING(SIZE(2)) Name ::= OCTET STRING(SIZE(2))
PkgdName ::= OCTET STRING(SIZE(4)) PkgdName ::= OCTET STRING(SIZE(4))
-- represents Package Name (2 octets) plus Property Name (2 octets) -- represents Package Name (2 octets) plus Property Name (2 octets)
-- To wildcard a package use 0xFFFF for first two octets, choose -- To wildcard a package use 0xFFFF for first two octets, choose
-- is not allowed. To reference native property tag specified in
-- Annex C, use 0x0000 as first two octets.
-- Wildcarding of Package Name is permitted only if Property Name is
-- also wildcarded.
Relation ::= ENUMERATED Relation ::= ENUMERATED
Internet draft MEGACO Protocol February 8, 2000
{ {
greaterThan(0), greaterThan(0),
smallerThan(1), smallerThan(1),
unequalTo(2), unequalTo(2),
... ...
} }
Internet draft MEGACO Protocol February 21, 2000
LocalRemoteDescriptor ::= SEQUENCE LocalRemoteDescriptor ::= SEQUENCE
{ {
propGrps SEQUENCE OF PropertyGroup, propGrps SEQUENCE OF PropertyGroup,
... ...
} }
PropertyGroup ::= SEQUENCE OF PropertyParm PropertyGroup ::= SEQUENCE OF PropertyParm
TerminationStateDescriptor ::= SEQUENCE TerminationStateDescriptor ::= SEQUENCE
{ {
propertyParms SEQUENCE OF PropertyParm, propertyParms SEQUENCE OF PropertyParm,
eventBufferFlag BOOLEAN, eventBufferControl EventBufferControl OPTIONAL,
serviceState ServiceState OPTIONAL, serviceState ServiceState OPTIONAL,
... ...
} }
EventBufferControl ::= ENUMERATED
{
Off(0),
LockStep(1),
...
}
ServiceState ::= ENUMERATED ServiceState ::= ENUMERATED
{ {
test(0), test(0),
outOfSvc(1), outOfSvc(1),
inSvc(2), inSvc(2),
... ...
} }
MuxDescriptor ::= SEQUENCE MuxDescriptor ::= SEQUENCE
{ {
muxType MuxType, muxType MuxType,
termList SEQUENCE OF TerminationID, termList SEQUENCE OF TerminationID,
nonStandardDataNonStandardData OPTIONAL,
... ...
} }
MuxType ::= ENUMERATED MuxType ::= ENUMERATED
{ {
h221(0), h221(0),
h223(1), h223(1),
h226(2), h226(2),
v76(3), v76(3),
... ...
} }
StreamID ::= INTEGER(0..65535) -- 16 bit unsigned integer Internet draft MEGACO Protocol February 21, 2000
Internet draft MEGACO Protocol February 8, 2000 StreamID ::= INTEGER(0..65535) -- 16 bit unsigned integer
EventsDescriptor ::= SEQUENCE EventsDescriptor ::= SEQUENCE
{ {
requestID RequestID, requestID RequestID,
eventList SEQUENCE OF RequestedEvent eventList SEQUENCE OF RequestedEvent
} }
RequestedEvent ::= SEQUENCE RequestedEvent ::= SEQUENCE
{ {
pkgdName PkgdName, pkgdName PkgdName,
skipping to change at page 85, line 52 skipping to change at page 90, line 4
{ {
pkgdName PkgdName, pkgdName PkgdName,
streamID StreamID OPTIONAL, streamID StreamID OPTIONAL,
eventAction SecondRequestedActions OPTIONAL, eventAction SecondRequestedActions OPTIONAL,
evParList SEQUENCE OF EventParameter evParList SEQUENCE OF EventParameter
} }
SecondRequestedActions ::= SEQUENCE SecondRequestedActions ::= SEQUENCE
{ {
keepActive BOOLEAN, keepActive BOOLEAN,
eventDM EventDM OPTIONAL,
signalsDescriptor SignalsDescriptor OPTIONAL,
Internet draft MEGACO Protocol February 8, 2000 Internet draft MEGACO Protocol February 21, 2000
eventDMEventDM OPTIONAL,
signalsDescriptor SignalsDescriptor OPTIONAL,
... ...
} }
EventBufferDescriptor ::= SEQUENCE OF ObservedEvent EventBufferDescriptor ::= SEQUENCE OF ObservedEvent
SignalsDescriptor ::= SEQUENCE OF SignalRequest SignalsDescriptor ::= SEQUENCE OF SignalRequest
SignalRequest ::=CHOICE SignalRequest ::=CHOICE
{ {
signal Signal, signal Signal,
skipping to change at page 86, line 32 skipping to change at page 90, line 34
id INTEGER(0..65535), id INTEGER(0..65535),
signalList SEQUENCE OF Signal signalList SEQUENCE OF Signal
} }
Signal ::= SEQUENCE Signal ::= SEQUENCE
{ {
signalName SignalName, signalName SignalName,
streamID StreamID OPTIONAL, streamID StreamID OPTIONAL,
sigType SignalType OPTIONAL, sigType SignalType OPTIONAL,
duration INTEGER (0..65535) OPTIONAL, duration INTEGER (0..65535) OPTIONAL,
notifyCompletion BOOLEAN, notifyCompletionBOOLEAN OPTIONAL,
keepActiveBOOLEAN OPTIONAL,
sigParList SEQUENCE OF SigParameter sigParList SEQUENCE OF SigParameter
} }
SignalType ::= ENUMERATED SignalType ::= ENUMERATED
{ {
brief(0), brief(0),
onOff(1), onOff(1),
timeOut(2), timeOut(2),
... ...
} }
SignalName ::= PkgdName SignalName ::= PkgdName
SigParameter ::= SEQUENCE SigParameter ::= SEQUENCE
{ {
sigParameterName Name, sigParameterName Name,
value Value value Value
} }
Internet draft MEGACO Protocol February 21, 2000
RequestID ::= INTEGER(0..4294967295) -- 32 bit unsigned integer RequestID ::= INTEGER(0..4294967295) -- 32 bit unsigned integer
ModemDescriptor ::= SEQUENCE ModemDescriptor ::= SEQUENCE
Internet draft MEGACO Protocol February 8, 2000
{ {
mtl SEQUENCE OF ModemType, mtl SEQUENCE OF ModemType,
mpl SEQUENCE OF PropertyParm mpl SEQUENCE OF PropertyParm,nonStandardData
NonStandardData OPTIONAL
} }
ModemType ::= ENUMERATED ModemType ::= ENUMERATED
{ {
v18(0), v18(0),
v22(1), v22(1),
v22bis(2), v22bis(2),
v32(3), v32(3),
v32bis(4), v32bis(4),
v34(5), v34(5),
skipping to change at page 87, line 52 skipping to change at page 92, line 4
} }
ServiceChangeParm ::= SEQUENCE ServiceChangeParm ::= SEQUENCE
{ {
serviceChangeMethod ServiceChangeMethod, serviceChangeMethod ServiceChangeMethod,
serviceChangeAddress ServiceChangeAddress OPTIONAL, serviceChangeAddress ServiceChangeAddress OPTIONAL,
serviceChangeVersion INTEGER(0..99) OPTIONAL, serviceChangeVersion INTEGER(0..99) OPTIONAL,
serviceChangeProfile ServiceChangeProfile OPTIONAL, serviceChangeProfile ServiceChangeProfile OPTIONAL,
serviceChangeReason Value, serviceChangeReason Value,
serviceChangeDelay INTEGER(0..4294967295) OPTIONAL, serviceChangeDelay INTEGER(0..4294967295) OPTIONAL,
Internet draft MEGACO Protocol February 21, 2000
-- 32 bit unsigned integer -- 32 bit unsigned integer
serviceChangeMgcId MId OPTIONAL, serviceChangeMgcId MId OPTIONAL,
timeStamp TimeNotation OPTIONAL, timeStamp TimeNotation OPTIONAL,
nonStandardDataNonStandardData OPTIONAL,
Internet draft MEGACO Protocol February 8, 2000
} }
ServiceChangeAddress ::= CHOICE ServiceChangeAddress ::= CHOICE
{ {
portNumber INTEGER(0..65535), -- TCP/UDP port number portNumber INTEGER(0..65535), -- TCP/UDP port number
ip4Address IP4Address, ip4Address IP4Address,
ip6Address IP6Address, ip6Address IP6Address,
domainName DomainName, domainName DomainName,
deviceName PathName, deviceName PathName,
mtpAddress OCTET STRING(SIZE(5)), mtpAddressOCTET STRING(SIZE(2)),
... ...
} }
ServiceChangeResParm ::= SEQUENCE ServiceChangeResParm ::= SEQUENCE
{ {
serviceChangeMgcId MId OPTIONAL, serviceChangeMgcId MId OPTIONAL,
serviceChangeAddress ServiceChangeAddress OPTIONAL, serviceChangeAddress ServiceChangeAddress OPTIONAL,
serviceChangeVersion INTEGER(0..99) OPTIONAL, serviceChangeVersion INTEGER(0..99) OPTIONAL,
serviceChangeProfile ServiceChangeProfile OPTIONAL serviceChangeProfile ServiceChangeProfile OPTIONAL
} }
skipping to change at page 88, line 51 skipping to change at page 93, line 4
profileName Name, profileName Name,
version INTEGER(0..99) version INTEGER(0..99)
} }
PackagesDescriptor ::= SEQUENCE OF PackagesItem PackagesDescriptor ::= SEQUENCE OF PackagesItem
PackagesItem ::= SEQUENCE PackagesItem ::= SEQUENCE
{ {
packageName Name, packageName Name,
packageVersion INTEGER(0..99) packageVersion INTEGER(0..99)
Internet draft MEGACO Protocol February 21, 2000
} }
StatisticsDescriptor ::= SEQUENCE OF StatisticsParameter StatisticsDescriptor ::= SEQUENCE OF StatisticsParameter
Internet draft MEGACO Protocol February 8, 2000
StatisticsParameter ::= SEQUENCE StatisticsParameter ::= SEQUENCE
{ {
statName PkgdName, statName PkgdName,
statValue Value statValue Value
} }
NonStandardData ::= SEQUENCE
{
nonStandardIdentifierNonStandardIdentifier,
dataOCTET STRING
}
NonStandardIdentifier::= CHOICE
{
objectOBJECT IDENTIFIER,
h221NonStandardH221NonStandard,
experimentalIA5STRING(SIZE(8)),
-- first two characters should be "X-" or "X+"
...
}
H221NonStandard ::= SEQUENCE
{ t35CountryCodeINTEGER(0..255), -- country, as per T.35
t35ExtensionINTEGER(0..255), -- assigned nationally
manufacturerCodeINTEGER(0..65535), -- assigned nationally
...
}
TimeNotation ::= SEQUENCE TimeNotation ::= SEQUENCE
{ {
date IA5String(SIZE(8)), -- yyyymmdd format date IA5String(SIZE(8)), -- yyyymmdd format
time IA5String(SIZE(8)) -- hhmmssss format time IA5String(SIZE(8)) -- hhmmssss format
} }
Value ::= OCTET STRING Value ::= OCTET STRING
END END
A.3. Digit maps and path names A.3. Digit maps and path names
>From a syntactic viewpoint, digit maps are strings with syntactic res- >From a syntactic viewpoint, digit maps are strings with syntactic res-
trictions imposed upon them. The syntax of valid digit maps is specified trictions imposed upon them. The syntax of valid digit maps is specified
in ABNF [RFC 2119]. The syntax for digit maps presented in this section
Internet draft MEGACO Protocol February 21, 2000
in ABNF [RFC 2234]. The syntax for digit maps presented in this section
is for illustrative purposes only. The definition of digitMap in Annex B is for illustrative purposes only. The definition of digitMap in Annex B
takes precedence in the case of differences between the two. takes precedence in the case of differences between the two.
digitMap = (digitString / LWSP "(" LWSP digitStringList LWSP digitMap = (digitString / LWSP "(" LWSP digitStringList LWSP ")"
")" LWSP) LWSP)
digitStringList = digitString *( LWSP "/" LWSP digitString ) digitStringList = digitString *( LWSP "/" LWSP digitString )
digitString = 1*(digitStringElement) digitString = 1*(digitStringElement)
digitStringElement = digitPosition [DOT] digitStringElement = digitPosition [DOT]
digitPosition = digitMapLetter / digitMapRange digitPosition = digitMapLetter / digitMapRange
digitMapRange = ("x" / LWSP "[" LWSP digitLetter LWSP "]" LWSP) digitMapRange = ("x" / LWSP "[" LWSP digitLetter LWSP "]" LWSP)
digitLetter = *((DIGIT "-" DIGIT) / digitMapLetter) digitLetter = *((DIGIT "-" DIGIT) / digitMapLetter)
digitMapLetter = DIGIT / %x41-4B / %x61-6B / ; Mapped events 0-9, digitMapLetter = DIGIT ;digits 0-9
; A-K (a-k) / %x41-4B / %x61-6B ;a-k and A-K
"L" ; Long duration modifier / "L" / "S" ;Inter-event timers
;(long, short)
/ "Z" ;Long duration event
LWSP = *(WSP / COMMENT / EOL) LWSP = *(WSP / COMMENT / EOL)
WSP = SP / HTAB WSP = SP / HTAB
COMMENT = ";" *(SafeChar / RestChar / WSP) EOL COMMENT = ";" *(SafeChar / RestChar / WSP) EOL
EOL = (CR [LF]) / LF EOL = (CR [LF]) / LF
SP = %x20 SP = %x20
HTAB = %x09 HTAB = %x09
CR = &x0D CR = %x0D
LF = %x0A LF = %x0A
SafeChar = DIGIT / ALPHA / "+" / "-" / "&" / "!" / "_" / "/" / SafeChar = DIGIT / ALPHA / "+" / "-" / "&" / "!" / "_" / "/" /
"'" / "?" / "@" / "^" / "`" / "~" / "*" / "$" / " "'" / "?" / "@" / "^" / "`" / "~" / "*" / "$" / "
Internet draft MEGACO Protocol February 8, 2000
"(" / ")" / "%" / "." "(" / ")" / "%" / "."
RestChar = ";" / "[" / "]" / "{" / "}" / ":" / "," / "#" / RestChar = ";" / "[" / "]" / "{" / "}" / ":" / "," / "#" /
"<" / ">" / "=" / %x22 "<" / ">" / "=" / %x22
DIGIT = %x30-39 ; digits 0 through 9 DIGIT = %x30-39 ; digits 0 through 9
ALPHA = %x41-5A / %x61-7A ; A-Z, a-z ALPHA = %x41-5A / %x61-7A ; A-Z, a-z
A path name is also a string with syntactic restrictions imposed upon A path name is also a string with syntactic restrictions imposed upon
it. The ABNF production defining it is copied from Annex B. it. The ABNF production defining it is copied from Annex B.