draft-ietf-mmusic-sdp-mux-attributes-00.txt   draft-ietf-mmusic-sdp-mux-attributes-01.txt 
Network Working Group S. Nandakumar Network Working Group S. Nandakumar
Internet-Draft Cisco Internet-Draft Cisco
Intended status: Standards Track December 11, 2013 Intended status: Standards Track February 14, 2014
Expires: June 14, 2014 Expires: August 18, 2014
A Framework for SDP Attributes when Multiplexing A Framework for SDP Attributes when Multiplexing
draft-ietf-mmusic-sdp-mux-attributes-00 draft-ietf-mmusic-sdp-mux-attributes-01
Abstract Abstract
The Session Description Protocol (SDP) provides mechanisms to The Session Description Protocol (SDP) provides mechanisms to
describe attributes of multimedia sessions and of individual media describe attributes of multimedia sessions and of individual media
streams (e.g., Real-time Transport Protocol (RTP) sessions) within a streams (e.g., Real-time Transport Protocol (RTP) sessions) within a
multimedia session. In the RTCWeb WG, there is a need to use a multimedia session. In the RTCWeb WG, there is a need to use a
single 5-tuple for sending and receiving media associated with single 5-tuple for sending and receiving media associated with
multiple media descriptions ("m=" lines). Such a requirement has multiple media descriptions ("m=" lines). Such a requirement has
raised concerns over the semantic implications of the SDP attributes raised concerns over the semantic implications of the SDP attributes
associated with the RTP Sessions multiplexed over a single transport associated with the RTP Media Streams multiplexed over a single
layer flow. transport layer flow.
The scope of this specification is to provide a framework for The scope of this specification is to provide a framework for
analyzing the multiplexing characteristics of SDP attributes. The analyzing the multiplexing characteristics of SDP attributes. The
specification also categorizes existing attributes based on the specification also categorizes existing attributes based on the
framework described herein. framework described herein.
Status of this Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
skipping to change at page 1, line 43 skipping to change at page 1, line 43
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
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 time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on June 14, 2014. This Internet-Draft will expire on August 18, 2014.
Copyright Notice Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
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the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. SDP Attribute Analysis Framework . . . . . . . . . . . . . . . 6 4. SDP Attribute Analysis Framework . . . . . . . . . . . . . . . 6
5. Analysis of Existing Attributes . . . . . . . . . . . . . . . 9 5. Analysis of Existing Attributes . . . . . . . . . . . . . . . 9
5.1. RFC4566 - SDP: Session Description Protocol . . . . . . . 10 5.1. RFC4566 - SDP: Session Description Protocol . . . . . . . 10
5.2. RFC4585 - RTP/AVPF . . . . . . . . . . . . . . . . . . . . 11 5.2. RFC4585 - RTP/AVPF . . . . . . . . . . . . . . . . . . . . 11
5.3. RFC5761 - Multiplexing RTP and RTCP . . . . . . . . . . . 11 5.3. RFC5761 - Multiplexing RTP and RTCP . . . . . . . . . . . 11
5.4. RFC4574 - SDP Label Attribute . . . . . . . . . . . . . . 11 5.4. RFC4574 - SDP Label Attribute . . . . . . . . . . . . . . 12
5.5. RFC5432 - QoS Mechanism Selection in SDP . . . . . . . . . 12 5.5. RFC5432 - QoS Mechanism Selection in SDP . . . . . . . . . 12
5.6. RFC4568 - SDP Security Descriptions . . . . . . . . . . . 12 5.6. RFC4568 - SDP Security Descriptions . . . . . . . . . . . 13
5.7. RFC5762 - RTP over DCCP . . . . . . . . . . . . . . . . . 13 5.7. RFC5762 - RTP over DCCP . . . . . . . . . . . . . . . . . 13
5.8. RFC6773 - DCCP-UDP Encapsulation . . . . . . . . . . . . . 14 5.8. RFC6773 - DCCP-UDP Encapsulation . . . . . . . . . . . . . 14
5.9. RFC5506 - Reduced-Size RTCP in RTP Profile . . . . . . . . 14 5.9. RFC5506 - Reduced-Size RTCP in RTP Profile . . . . . . . . 14
5.10. RFC6787 - Media Resource Control Protocol Version 2 . . . 15 5.10. RFC6787 - Media Resource Control Protocol Version 2 . . . 15
5.11. RFC5245 - Interactive Connectivity Establishment (ICE) . . 15 5.11. RFC5245 - Interactive Connectivity Establishment (ICE) . . 15
5.12. RFC5285 - RTP Header Extensions . . . . . . . . . . . . . 16 5.12. RFC5285 - RTP Header Extensions . . . . . . . . . . . . . 17
5.13. RFC3605 - RTCP attribute in SDP . . . . . . . . . . . . . 17 5.13. RFC3605 - RTCP attribute in SDP . . . . . . . . . . . . . 17
5.14. RFC5576 - Source-Specific SDP Attributes . . . . . . . . . 17 5.14. RFC5576 - Source-Specific SDP Attributes . . . . . . . . . 17
5.15. RFC6236 - Image Attributes in SDP . . . . . . . . . . . . 18 5.15. RFC6236 - Image Attributes in SDP . . . . . . . . . . . . 18
5.16. RFC6285 - Rapid Acquisition of Multicast RTP Sessions . . 18 5.16. RFC6285 - Rapid Acquisition of Multicast RTP Sessions . . 19
5.17. RFC6230 - Media Control Channel Framework . . . . . . . . 19 5.17. RFC6230 - Media Control Channel Framework . . . . . . . . 19
5.18. RFC6364 - SDP Elements for FEC Framework . . . . . . . . . 19 5.18. RFC6364 - SDP Elements for FEC Framework . . . . . . . . . 19
5.19. RFC4796 - Content Attribute . . . . . . . . . . . . . . . 20 5.19. RFC4796 - Content Attribute . . . . . . . . . . . . . . . 20
5.20. RFC3407 - SDP Simple Capability Declaration . . . . . . . 20 5.20. RFC3407 - SDP Simple Capability Declaration . . . . . . . 20
5.21. RFC6284 - Port Mapping between Unicast and Multicast 5.21. RFC6284 - Port Mapping between Unicast and Multicast
RTP Sessions . . . . . . . . . . . . . . . . . . . . . . . 21 RTP Sessions . . . . . . . . . . . . . . . . . . . . . . . 21
5.22. RFC6714 - MSRP-CEMA . . . . . . . . . . . . . . . . . . . 21 5.22. RFC6714 - MSRP-CEMA . . . . . . . . . . . . . . . . . . . 21
5.23. RFC4583 - SDP Format for BFCP Streams . . . . . . . . . . 21 5.23. RFC4583 - SDP Format for BFCP Streams . . . . . . . . . . 22
5.24. RFC5547 - SDP Offer/Answer for File Transfer . . . . . . . 22 5.24. RFC5547 - SDP Offer/Answer for File Transfer . . . . . . . 22
5.25. RFC6489 - SDP and RTP Media Loopback Extension . . . . . . 22 5.25. RFC6489 - SDP and RTP Media Loopback Extension . . . . . . 23
5.26. RFC5760 - RTCP with Unicast Feedback . . . . . . . . . . . 23 5.26. RFC5760 - RTCP with Unicast Feedback . . . . . . . . . . . 23
5.27. RFC3611 - RTCP XR . . . . . . . . . . . . . . . . . . . . 23 5.27. RFC3611 - RTCP XR . . . . . . . . . . . . . . . . . . . . 24
5.28. RFC5939 - SDP Capability Negotiation . . . . . . . . . . . 24 5.28. RFC5939 - SDP Capability Negotiation . . . . . . . . . . . 24
5.29. draft-ietf-mmusic-sdp-media-capabilities . . . . . . . . . 24 5.29. RFC6781 - SDP Media Capabilities Negotiation . . . . . . . 25
5.30. RFC4567 - Key Management Extensions for SDP and RTSP . . . 25 5.30. RFC4567 - Key Management Extensions for SDP and RTSP . . . 26
5.31. RFC4572 - Comedia over TLS in SDP . . . . . . . . . . . . 26 5.31. RFC4572 - Comedia over TLS in SDP . . . . . . . . . . . . 26
5.32. RFC4570 - SDP Source Filters . . . . . . . . . . . . . . . 26 5.32. RFC4570 - SDP Source Filters . . . . . . . . . . . . . . . 27
5.33. RFC6128 - RTCP Port for Multicast Sessions . . . . . . . . 27 5.33. RFC6128 - RTCP Port for Multicast Sessions . . . . . . . . 27
5.34. RFC6189 - ZRTP . . . . . . . . . . . . . . . . . . . . . . 27 5.34. RFC6189 - ZRTP . . . . . . . . . . . . . . . . . . . . . . 28
5.35. RFC4145 - Connection-Oriented Media . . . . . . . . . . . 28 5.35. RFC4145 - Connection-Oriented Media . . . . . . . . . . . 28
5.36. RFC5159 - OMA BCAST SDP Attributes . . . . . . . . . . . . 28 5.36. RFC5159 - OMA BCAST SDP Attributes . . . . . . . . . . . . 29
5.37. RFC6193 - Media Description for IKE in SDP . . . . . . . . 29 5.37. RFC6193 - Media Description for IKE in SDP . . . . . . . . 29
5.38. RFC6064 - SDP and RTSP Extensions for 3GPP . . . . . . . . 30 5.38. RFC6064 - SDP and RTSP Extensions for 3GPP . . . . . . . . 30
5.39. RFC3108 - ATM SDP . . . . . . . . . . . . . . . . . . . . 32 5.39. RFC3108 - ATM SDP . . . . . . . . . . . . . . . . . . . . 33
5.40. 3GPP TS 24.182 . . . . . . . . . . . . . . . . . . . . . . 33 5.40. 3GPP TS 24.182 . . . . . . . . . . . . . . . . . . . . . . 34
5.41. 3GPP TS 24.183 . . . . . . . . . . . . . . . . . . . . . . 34 5.41. 3GPP TS 24.183 . . . . . . . . . . . . . . . . . . . . . . 34
5.42. 3GPP TS 24.229 . . . . . . . . . . . . . . . . . . . . . . 34 5.42. 3GPP TS 24.229 . . . . . . . . . . . . . . . . . . . . . . 35
5.43. ITU T.38 . . . . . . . . . . . . . . . . . . . . . . . . . 35 5.43. ITU T.38 . . . . . . . . . . . . . . . . . . . . . . . . . 36
5.44. ITU-T H.248.15 . . . . . . . . . . . . . . . . . . . . . . 35 5.44. ITU-T H.248.15 . . . . . . . . . . . . . . . . . . . . . . 36
5.45. RFC4975 - The Message Session Relay Protocol . . . . . . . 36 5.45. RFC4975 - The Message Session Relay Protocol . . . . . . . 37
5.46. Historical . . . . . . . . . . . . . . . . . . . . . . . . 37 5.46. Historical . . . . . . . . . . . . . . . . . . . . . . . . 38
6. bwtype Attribute Analysis . . . . . . . . . . . . . . . . . . 37 6. bwtype Attribute Analysis . . . . . . . . . . . . . . . . . . 38
6.1. RFC4566 - SDP: Session Description Protocol . . . . . . . 37 6.1. RFC4566 - SDP: Session Description Protocol . . . . . . . 39
6.2. RFC3556 - SDP Bandwidth Modifiers for RTCP Bandwidth . . . 38 6.2. RFC3556 - SDP Bandwidth Modifiers for RTCP Bandwidth . . . 39
6.3. RFC3890 - Bandwidth Modifier for SDP . . . . . . . . . . . 39 6.3. RFC3890 - Bandwidth Modifier for SDP . . . . . . . . . . . 40
7. rtcp-fb Attribute Analysis . . . . . . . . . . . . . . . . . . 39 7. rtcp-fb Attribute Analysis . . . . . . . . . . . . . . . . . . 40
7.1. RFC4585 - RTP/AVPF . . . . . . . . . . . . . . . . . . . . 39 7.1. RFC4585 - RTP/AVPF . . . . . . . . . . . . . . . . . . . . 41
7.2. RFC5104 - Codec Control Messages in AVPF . . . . . . . . . 40 7.2. RFC5104 - Codec Control Messages in AVPF . . . . . . . . . 41
7.3. RFC6285 - Unicast-Based RAMS . . . . . . . . . . . . . . . 41 7.3. RFC6285 - Unicast-Based RAMS . . . . . . . . . . . . . . . 42
7.4. RFC6679 - ECN for RTP over UDP/IP . . . . . . . . . . . . 41 7.4. RFC6679 - ECN for RTP over UDP/IP . . . . . . . . . . . . 42
7.5. RFC6642 - Third-Party Loss Report . . . . . . . . . . . . 41 7.5. RFC6642 - Third-Party Loss Report . . . . . . . . . . . . 43
7.6. RFC5104 - Codec Control Messages in AVPF . . . . . . . . . 42 7.6. RFC5104 - Codec Control Messages in AVPF . . . . . . . . . 43
8. group Attribute Analysis . . . . . . . . . . . . . . . . . . . 42 8. group Attribute Analysis . . . . . . . . . . . . . . . . . . . 44
8.1. RFC5888 - SDP Grouping Framework . . . . . . . . . . . . . 42 8.1. RFC5888 - SDP Grouping Framework . . . . . . . . . . . . . 44
8.2. RFC3524 - Mapping Media Streams to Resource 8.2. RFC3524 - Mapping Media Streams to Resource
Reservation Flows . . . . . . . . . . . . . . . . . . . . 43 Reservation Flows . . . . . . . . . . . . . . . . . . . . 44
8.3. RFC4091 - ANAT Semantics . . . . . . . . . . . . . . . . . 43 8.3. RFC4091 - ANAT Semantics . . . . . . . . . . . . . . . . . 44
8.4. RFC5956 - FEC Grouping Semantics in SDP . . . . . . . . . 44 8.4. RFC5956 - FEC Grouping Semantics in SDP . . . . . . . . . 45
8.5. RFC5583 - Signaling Media Decoding Dependency in SDP . . . 44 8.5. RFC5583 - Signaling Media Decoding Dependency in SDP . . . 45
9. ssrc-group Attribute Analysis . . . . . . . . . . . . . . . . 45 9. ssrc-group Attribute Analysis . . . . . . . . . . . . . . . . 46
9.1. RFC5576 - Source-Specific SDP Attributes . . . . . . . . . 45 9.1. RFC5576 - Source-Specific SDP Attributes . . . . . . . . . 46
10. QoS Mechanism Token Analysis . . . . . . . . . . . . . . . . . 45 10. QoS Mechanism Token Analysis . . . . . . . . . . . . . . . . . 46
10.1. RFC5432 - QoS Mechanism Selection in SDP . . . . . . . . . 45 10.1. RFC5432 - QoS Mechanism Selection in SDP . . . . . . . . . 46
11. k= Attribute Analysis . . . . . . . . . . . . . . . . . . . . 45 11. k= Attribute Analysis . . . . . . . . . . . . . . . . . . . . 47
11.1. RFC4566 SDP: Session Description Protocol . . . . . . . . 46 11.1. RFC4566 SDP: Session Description Protocol . . . . . . . . 47
12. content Atribute Analysis . . . . . . . . . . . . . . . . . . 46 12. content Atribute Analysis . . . . . . . . . . . . . . . . . . 47
12.1. RFC4796 - MSRP Relays . . . . . . . . . . . . . . . . . . 46 12.1. RFC4796 . . . . . . . . . . . . . . . . . . . . . . . . . 47
13. Payload Formats . . . . . . . . . . . . . . . . . . . . . . . 46 13. Payload Formats . . . . . . . . . . . . . . . . . . . . . . . 47
13.1. RFC5109 - RTP Payload Format for Generic FEC . . . . . . . 46 13.1. RFC5109 - RTP Payload Format for Generic FEC . . . . . . . 47
14. Multiplexing Media Streams and DSCP Markings . . . . . . . . . 47 14. Multiplexing Media Streams and DSCP Markings . . . . . . . . . 48
14.1. Option A . . . . . . . . . . . . . . . . . . . . . . . . . 47 14.1. Option A . . . . . . . . . . . . . . . . . . . . . . . . . 48
14.2. Option B . . . . . . . . . . . . . . . . . . . . . . . . . 48 14.2. Option B . . . . . . . . . . . . . . . . . . . . . . . . . 49
15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 48 15. Multiplexing Considerations for Encapsulating Attributes . . . 49
16. Security Considerations . . . . . . . . . . . . . . . . . . . 48 16. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 52
17. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 48 17. Security Considerations . . . . . . . . . . . . . . . . . . . 53
18. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . . 49 18. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 53
19. References . . . . . . . . . . . . . . . . . . . . . . . . . . 50 19. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . . 53
19.1. Normative References . . . . . . . . . . . . . . . . . . . 50 20. References . . . . . . . . . . . . . . . . . . . . . . . . . . 54
19.2. Informative References . . . . . . . . . . . . . . . . . . 50 20.1. Normative References . . . . . . . . . . . . . . . . . . . 54
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 56 20.2. Informative References . . . . . . . . . . . . . . . . . . 54
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 60
1. Introduction 1. Introduction
Real-Time Communication Web (RTCWeb) framework requires Real-time Real-Time Communication Web (RTCWeb) framework requires Real-time
Transport Protocol as the media transport protocol and Session Transport Protocol (RTP) as the media transport protocol and Session
Description Protocol (SDP) [RFC4566] for describing and negotiating Description Protocol (SDP) [RFC4566] for describing and negotiating
multi-media communication sessions. multi-media communication sessions.
SDP defines several attributes for capturing characteristics that SDP defines several attributes for capturing characteristics that
apply to the individual media descriptions (described by "m=" lines") apply to the individual media descriptions (described by "m=" lines")
and the overall multimedia session. Typically different media types and the overall multimedia session. Typically different media types
(audio, video etc) described using different media descriptions (audio, video etc) described using different media descriptions
represent separate RTP Sessions that are carried over individual represent separate RTP Sessions that are carried over individual
transport layer flows. However, in the RTCWeb WG, a requirement has transport layer flows. However in the IETF RTCWEB WG, a need to use
arisen to multiplex several RTP Sessions over a single transport a single 5-tuple for sending and receiving media associated with
layer flow. This in turn has made necessary to understand the multiple SDP media descriptions ("m=" lines) has been identified.
interpretation and usage of the SDP attributes defined for the This would e.g. allow the usage of a single set of Interactive
Connectivity Establishment (ICE) [RFC5245] candidates for multiple
media descriptions. This in turn has made necessary to understand
the interpretation and usage of the SDP attributes defined for the
multiplexed media descriptions. multiplexed media descriptions.
Given the number of SDP attributes registered with the IANA [IANA] Given the number of SDP attributes registered with the IANA [IANA]
and possibility of new attributes being defined in the future, there and possibility of new attributes being defined in the future, there
is need for generic future-proof framework to analyze these is need for generic future-proof framework to analyze these
attributes for their applicability in the transport multiplexing use- attributes for their applicability in the transport multiplexing use-
cases. cases.
The document starts with providing the motivation for requiring such The document starts with providing the motivation for requiring such
a framework. This is followed by introduction to the SDP attribute a framework. This is followed by introduction to the SDP attribute
skipping to change at page 5, line 48 skipping to change at page 6, line 4
"RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be
interpreted as described in [RFC2119]. interpreted as described in [RFC2119].
3. Motivation 3. Motivation
The time and complications of setting up ICE [RFC5245] and DTLS-SRTP The time and complications of setting up ICE [RFC5245] and DTLS-SRTP
[RFC5763] transports for use by RTP, and conservation of ports, forms [RFC5763] transports for use by RTP, and conservation of ports, forms
an requirement to try and reduce the number of transport level flows an requirement to try and reduce the number of transport level flows
needed. This has resulted in the definition of ways, such as, needed. This has resulted in the definition of ways, such as,
[I-D.ietf-mmusic-sdp-bundle-negotiation] and [I-D.ietf-mmusic-sdp-bundle-negotiation] and
[I-D.ietf-avt-multiplexing-rtp] to multiplex RTP over a single [I-D.ietf-avt-multiplexing-rtp] to multiplex RTP over a single
transport flow in order to preserve network resources such as port transport flow in order to preserve network resources such as port
numbers. This imposes further restrictions on applicability of these numbers. This imposes further restrictions on applicability of these
SDP attributes as they are defined today. SDP attributes as they are defined today.
The specific problem is that there are attribute combinations which The specific problem is that there are attribute combinations which
make sense when specified on independent m-lines -- as with classical make sense when specified on independent m-lines -- as with classical
SDP -- that do not make sense when those m-lines are then multiplexed SDP -- that do not make sense when those m-lines are then multiplexed
over the same transport. To give an obvious example, ICE permits over the same transport. To give an obvious example, ICE permits
each m-mline to have an independently specified ice-ufrag attribute. each m=line to have an independently specified ice-ufrag attribute.
However, if the media from multiple m-lines is multiplexed over the However, if the media from multiple m-lines is multiplexed over the
same ICE component, then the meaning of media-level ice-ufrag same ICE component, then the meaning of media-level ice-ufrag
attributes becomes muddled. attributes becomes muddled.
As of today there are close to 250 SDP attributes registered with the As of today there are close to 250 SDP attributes registered with the
IANA [IANA] and more will be added in the future. There is no IANA [IANA] and more will be added in the future. There is no
clearly defined procedure to establish the validity/applicability of clearly defined procedure to establish the validity/applicability of
these attribute when used with transport multiplexing. these attribute when used with transport multiplexing.
4. SDP Attribute Analysis Framework 4. SDP Attribute Analysis Framework
skipping to change at page 7, line 19 skipping to change at page 7, line 19
t=0 0 t=0 0
m=audio 49172 RTP/AVP 99 m=audio 49172 RTP/AVP 99
a=sendonly a=sendonly
a=label:1 a=label:1
a=rtpmap:99 iLBC/8000 a=rtpmap:99 iLBC/8000
m=video 49172 RTP/AVP 31 m=video 49172 RTP/AVP 31
a=recvonly a=recvonly
a=label:2 a=label:2
a=rtpmap:31 H261/90000 a=rtpmap:31 H261/90000
NOT RECOMMENDED Attributes where multiplexing is not recommended if NOT RECOMMENDED Attributes that are recommended against multiplexing
these attributes are in use in the SDP since doing so MAY result since their usage under multiplexing might lead to incorrect
in incorrect behaviors behavior.
Example: Multiplexing media descriptions having attribute zrtp- Example: Multiplexing media descriptions having attribute zrtp-
hash defined with the media descriptions lacking it, would either hash defined with the media descriptions lacking it, would either
complicate the handling of multiplexed stream or fail complicate the handling of multiplexed streams or might fail
multiplexing. multiplexing altogether.
v=0 v=0
o=bob 2890844527 2890844527 IN IP4 client.biloxi.example.com o=bob 2890844527 2890844527 IN IP4 client.biloxi.example.com
s= s=
c=IN IP4 client.biloxi.example.com c=IN IP4 client.biloxi.example.com
t=0 0 t=0 0
m=audio 3456 RTP/AVP 97 // with zrtp m=audio 3456 RTP/AVP 97 // with zrtp
a=rtpmap:97 iLBC/8000 a=rtpmap:97 iLBC/8000
<allOneLine> <allOneLine>
a=zrtp-hash:1.10 fe30efd02423cb054e50efd0248742ac7a52c8f91bc2 a=zrtp-hash:1.10 fe30efd02423cb054e50efd0248742ac7a52c8f91bc2
df881ae642c371ba46df df881ae642c371ba46df
</allOneLine> </allOneLine>
m=video 34567 RTP/AVP 31 //without zrtp m=video 34567 RTP/AVP 31 //without zrtp
a=rtpmap:31 H261/90000 a=rtpmap:31 H261/90000
IDENTICAL Attributes that MUST be identical across all the media IDENTICAL Attributes that MUST be identical across all the media
descriptions being multiplexed. descriptions being multiplexed.
Attributes such as rtcp-mux fall into this category. Since RTCP Attributes such as rtcp-mux fall into this category. Since RTCP
reporting is done per RTP Session, there is no way to receive RTCP reporting is done per RTP Session, RTCP Multiplexing MUST to
control data for the video m=line in the example below. Hence enabled for both the audio and video m=lines in the example below
rtcp-mux MUST be repeated for the video m=line as well, when if they are transported over a single 5-tuple.
multiplexed.
v=0 v=0
o=bob 2890844527 2890844527 IN IP4 client.biloxi.example.com o=bob 2890844527 2890844527 IN IP4 client.biloxi.example.com
s= s=
c=IN IP4 client.biloxi.example.com c=IN IP4 client.biloxi.example.com
t=0 0 t=0 0
m=audio 34567 RTP/AVP 97 m=audio 34567 RTP/AVP 97
a=rtcp-mux a=rtcp-mux
m=video 34567 RTP/AVP 31 m=video 34567 RTP/AVP 31
a=rtpmap:31 H261/90000 a=rtpmap:31 H261/90000
skipping to change at page 11, line 14 skipping to change at page 11, line 14
RFC4566 Attribute Analysis RFC4566 Attribute Analysis
5.2. RFC4585 - RTP/AVPF 5.2. RFC4585 - RTP/AVPF
RFC4585 [RFC4585] defines an extension to the Audio-visual Profile RFC4585 [RFC4585] defines an extension to the Audio-visual Profile
(AVP) that enables receivers to provide, statistically, more (AVP) that enables receivers to provide, statistically, more
immediate feedback to the senders and thus allows for short-term immediate feedback to the senders and thus allows for short-term
adaptation and efficient feedback-based repair mechanisms to be adaptation and efficient feedback-based repair mechanisms to be
implemented. implemented.
+----------+-----------------------------------+-------+------------+ +----------+-------------------------------------+-------+----------+
| Attr | Notes | Level | Category | | Attr | Notes | Level | Category |
| Name | | | | | Name | | | |
+----------+-----------------------------------+-------+------------+ +----------+-------------------------------------+-------+----------+
| rtcp-fb | Repeated if the | M | IDENTICAL | | rtcp-fb | The combination of a particular | M | NORMAL |
| | Codec-Configuration is same | | | | | Payload Type along with the m=line | | |
| | across all the bundled m=lines. | | | | | identify the scope and | | |
| | | | | | | applicability of a given RTCP | | |
+----------+-----------------------------------+-------+------------+ | | feedback to a particular RTP | | |
| | Stream. | | |
| | | | |
+----------+-------------------------------------+-------+----------+
RFC4585 Attribute Analysis RFC4585 Attribute Analysis
OPEN ISSUE:Codec-Configuration needs to be defined. Since RTCP feedback attributes are Payload Type (PT) scoped, the
usage of identical Payload Type values across multiplexed m=lines is
described in [I-D.ietf-mmusic-sdp-bundle-negotiation].
5.3. RFC5761 - Multiplexing RTP and RTCP 5.3. RFC5761 - Multiplexing RTP and RTCP
RFC5761 [RFC5761] discusses issues that arise when multiplexing RTP RFC5761 [RFC5761] discusses issues that arise when multiplexing RTP
data packets and RTP Control Protocol (RTCP) packets on a single UDP data packets and RTP Control Protocol (RTCP) packets on a single UDP
port. It describes when such multiplexing is and is not appropriate, port. It describes when such multiplexing is and is not appropriate,
and it explains how the Session Description Protocol (SDP) can be and it explains how the Session Description Protocol (SDP) can be
used to signal multiplexed sessions. used to signal multiplexed sessions.
+-----------+----------------------------------+-------+------------+ +-----------+----------------------------------+-------+------------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+-----------+----------------------------------+-------+------------+ +-----------+----------------------------------+-------+------------+
| rtcp-mux | RTCP muxing should be repeated | M | IDENTICAL | | rtcp-mux | RTP and RTCP Multiplexing affect | M | IDENTICAL |
| | across all the m=lines | | | | | the entire RTP Session | | |
| | | | | | | | | |
+-----------+----------------------------------+-------+------------+ +-----------+----------------------------------+-------+------------+
RFC5761 Attribute Analysis RFC5761 Attribute Analysis
5.4. RFC4574 - SDP Label Attribute 5.4. RFC4574 - SDP Label Attribute
RFC4574 [RFC4574] defines a new Session Description Protocol (SDP) RFC4574 [RFC4574] defines a new Session Description Protocol (SDP)
media-level attribute: "label". The "label" attribute carries a media-level attribute: "label". The "label" attribute carries a
pointer to a media stream in the context of an arbitrary network pointer to a media stream in the context of an arbitrary network
skipping to change at page 12, line 25 skipping to change at page 12, line 32
RFC4574 Attribute Analysis RFC4574 Attribute Analysis
5.5. RFC5432 - QoS Mechanism Selection in SDP 5.5. RFC5432 - QoS Mechanism Selection in SDP
RFC5432 [RFC5432] defines procedures to negotiate QOS mechanisms RFC5432 [RFC5432] defines procedures to negotiate QOS mechanisms
using the Session Description Protocol (SDP) offer/answer model. using the Session Description Protocol (SDP) offer/answer model.
+----------------+-------------------------------+-------+----------+ +----------------+-------------------------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+----------------+-------------------------------+-------+----------+ +----------------+-------------------------------+-------+----------+
| qos-mech-send | Since QOS mechanism are | B | NORMAL | | qos-mech-send | A single DSCP code point per | B | NORMAL |
| | signaled per flow, | | | | | flow being multiplexed | | |
| | multiplexing multiple m=lines | | | | | doesn't impact multiplexing | | |
| | has no impact on per m=line | | | | | since QOS mechanisms are | | |
| | QOS mechanism. | | | | | signaled/scoped per flow. | | |
| | | | | | | | | |
| qos-mech-recv | Since QOS mechanism are | B | NORMAL | | qos-mech-recv | A single DSCP code point per | B | NORMAL |
| | signaled per flow, | | | | | flow being multiplexed | | |
| | multiplexing multiple m=lines | | | | | doesn't impact multiplexing | | |
| | has no impact on per m=line | | | | | since QOS mechanisms are | | |
| | QOS mechanism. | | | | | signaled/scoped per flow. | | |
| | | | | | | | | |
+----------------+-------------------------------+-------+----------+ +----------------+-------------------------------+-------+----------+
RFC5432 Attribute Analysis RFC5432 Attribute Analysis
Multiplexing consideration when multiple DSCP code points are defined
per flow can be found in Section 14
5.6. RFC4568 - SDP Security Descriptions 5.6. RFC4568 - SDP Security Descriptions
RFC4568 [RFC4568] defines a Session Description Protocol (SDP) RFC4568 [RFC4568] defines a Session Description Protocol (SDP)
cryptographic attribute for unicast media streams. The attribute cryptographic attribute for unicast media streams. The attribute
describes a cryptographic key and other parameters that serve to describes a cryptographic key and other parameters that serve to
configure security for a unicast media stream in either a single configure security for a unicast media stream in either a single
message or a roundtrip exchange. message or a roundtrip exchange.
+---------+----------------------------------+-------+--------------+ +--------+---------------------------------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+---------+----------------------------------+-------+--------------+ +--------+---------------------------------------+-------+----------+
| crypto | The multiplexing scheme MUST | M | TRANSPORT | | crypto | Refer to section 6.2.5 of | M | SPECIAL |
| | ensure unique SSRCs across all | | | | | [I-D.ietf-mmusic-sdp-bundle-negotiati | | |
| | the media lines multiplexed. In | | | | | on] | | |
| | that case, cryptographic keys | | | | | | | |
| | corresponding to the underlying | | | +--------+---------------------------------------+-------+----------+
| | transport is used. | | |
| | | | |
| crypto | If the multiplexing scheme | M | NOT |
| | cannot ensure unique SSRCs | | RECOMMENDED |
| | across all the media lines, | | |
| | multiplexing MUST NOT be | | |
| | performed. | | |
| | | | |
+---------+----------------------------------+-------+--------------+
RFC4568 Attribute Analysis RFC4568 Attribute Analysis
If the multiplexing scheme cannot ensure unique SSRCs across all the
media lines, multiplexing MUST NOT be performed.
5.7. RFC5762 - RTP over DCCP 5.7. RFC5762 - RTP over DCCP
The Real-time Transport Protocol (RTP) is a widely used transport for The Real-time Transport Protocol (RTP) is a widely used transport for
real-time multimedia on IP networks. The Datagram Congestion Control real-time multimedia on IP networks. The Datagram Congestion Control
Protocol (DCCP) is a transport protocol that provides desirable Protocol (DCCP) is a transport protocol that provides desirable
services for real-time applications. RFC5762 [RFC5762] specifies a services for real-time applications. RFC5762 [RFC5762] specifies a
mapping of RTP onto DCCP, along with associated signaling, such that mapping of RTP onto DCCP, along with associated signaling, such that
real-time applications can make use of the services provided by DCCP real-time applications can make use of the services provided by DCCP
+--------------------+---------------------+---------+--------------+ +--------------------+---------------------+---------+--------------+
| Name | Notes | Current | Category | | Name | Notes | Current | Category |
+--------------------+---------------------+---------+--------------+ +--------------------+---------------------+---------+--------------+
| dccp-service-code | If RFC 6773 is not | M | NOT | | dccp-service-code | If RFC6773 is not | M | NOT |
| | being used in | | RECOMMENDED | | | being used in | | RECOMMENDED |
| | addition to RFC | | | | | addition to | | |
| | 5762, the port in | | | | | RFC5762, the port | | |
| | the m= line is a | | | | | in the m= line is a | | |
| | DCCP port. DCCP | | | | | DCCP port. DCCP | | |
| | being a connection | | | | | being a connection | | |
| | oriented protocol, | | | | | oriented protocol, | | |
| | does not allow | | | | | does not allow | | |
| | multiple | | | | | multiple | | |
| | connections on the | | | | | connections on the | | |
| | same 5-tuple. | | | | | same 5-tuple. | | |
| | | | | | | | | |
+--------------------+---------------------+---------+--------------+ +--------------------+---------------------+---------+--------------+
RFC5762 Attribute Analysis RFC5762 Attribute Analysis
If RFC 6773 is being used in addition to RFC 5762 and provided that If RFC6773 is being used in addition to RFC5762 and provided that
DCCP-in-UDP layer has additional demultiplexing, then it may be DCCP-in-UDP layer has additional demultiplexing, then it may be
possible to use different DCCP service codes for each DCCP flow, possible to use different DCCP service codes for each DCCP flow,
given each uses a different DCCP port. Although doing so might given each uses a different DCCP port. Although doing so might
conflict with the media type of the m= line. None of this is conflict with the media type of the m= line. None of this is
standardized yet and it wouldn't work as explained. Hence standardized yet and it wouldn't work as explained. Hence
multiplexing MUST NOT be performed even in this alternate scenario. multiplexing MUST NOT be performed even in this alternate scenario.
5.8. RFC6773 - DCCP-UDP Encapsulation 5.8. RFC6773 - DCCP-UDP Encapsulation
RFC6773 [RFC6773] document specifies an alternative encapsulation of RFC6773 [RFC6773] document specifies an alternative encapsulation of
skipping to change at page 14, line 35 skipping to change at page 14, line 36
| | performed due to potential | | RECOMMENDED | | | performed due to potential | | RECOMMENDED |
| | conflict between the port | | | | | conflict between the port | | |
| | used for DCCP | | | | | used for DCCP | | |
| | en/decapsulation and the | | | | | en/decapsulation and the | | |
| | RTP. | | | | | RTP. | | |
| | | | | | | | | |
+------------+-------------------------------+-------+--------------+ +------------+-------------------------------+-------+--------------+
RFC6773 Attribute Analysis RFC6773 Attribute Analysis
Since RFC6773 is about tunnelling DCCP in UDP, with the UDP port
being the port of the DCCP en-/de-capsulation service. This
encapsulation allows arbitrary DCCP packets to be encapsulated and
the DCCP port choosen MAY conflict with the port chosen for the RTP
traffic.
For multiplexing several DCCP-in-UDP encapsulations on the same UDP
port, with no RTP traffic on the same port implies collapsing several
DCCP port spaces together. This MAY or MAY NOT work depending on the
nature of DCCP encapsulations and ports choses thus rendering it to
be very application dependant.
5.9. RFC5506 - Reduced-Size RTCP in RTP Profile 5.9. RFC5506 - Reduced-Size RTCP in RTP Profile
RFC5506 [RFC5506] discusses benefits and issues that arise when RFC5506 [RFC5506] discusses benefits and issues that arise when
allowing Real-time Transport Protocol (RTCP) packets to be allowing Real-time Transport Protocol (RTCP) packets to be
transmitted with reduced size. transmitted with reduced size.
+-------------+--------------------------------+-------+------------+ +-------------+--------------------------------+-------+------------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+-------------+--------------------------------+-------+------------+ +-------------+--------------------------------+-------+------------+
| rtcp-rsize | RTCP reduced size MUST be | M | IDENTICAL | | rtcp-rsize | Reduced size RTCP affects the | M | IDENTICAL |
| | repeated across all the | | | | | entire RTP Session | | |
| | m=lines | | |
| | | | | | | | | |
+-------------+--------------------------------+-------+------------+ +-------------+--------------------------------+-------+------------+
RFC5506 Attribute Analysis RFC5506 Attribute Analysis
5.10. RFC6787 - Media Resource Control Protocol Version 2 5.10. RFC6787 - Media Resource Control Protocol Version 2
The Media Resource Control Protocol Version 2 (MRCPv2) allows client The Media Resource Control Protocol Version 2 (MRCPv2) allows client
hosts to control media service resources such as speech synthesizers, hosts to control media service resources such as speech synthesizers,
recognizers, verifiers, and identifiers residing in servers on the recognizers, verifiers, and identifiers residing in servers on the
skipping to change at page 15, line 29 skipping to change at page 15, line 40
speech resource server. RFC6787 [RFC6787] defines attributes for speech resource server. RFC6787 [RFC6787] defines attributes for
this purpose. this purpose.
+-----------+---------------+-------+----------+ +-----------+---------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+-----------+---------------+-------+----------+ +-----------+---------------+-------+----------+
| resource | Not Impacted | M | NORMAL | | resource | Not Impacted | M | NORMAL |
| | | | | | | | | |
| channel | Not Impacted | M | NORMAL | | channel | Not Impacted | M | NORMAL |
| | | | | | | | | |
| | Not Impacted | M | NORMAL |
| | | | |
+-----------+---------------+-------+----------+ +-----------+---------------+-------+----------+
RFC6787 Attribute Analysis RFC6787 Attribute Analysis
5.11. RFC5245 - Interactive Connectivity Establishment (ICE) 5.11. RFC5245 - Interactive Connectivity Establishment (ICE)
RFC5245 [RFC5245] describes a protocol for Network Address RFC5245 [RFC5245] describes a protocol for Network Address
Translator(NAT) traversal for UDP-based multimedia sessions Translator(NAT) traversal for UDP-based multimedia sessions
established with the offer/answer model. This protocol is called established with the offer/answer model. This protocol is called
Interactive Connectivity Establishment (ICE). ICE makes use of the Interactive Connectivity Establishment (ICE). ICE makes use of the
skipping to change at page 16, line 12 skipping to change at page 16, line 14
protocol utilizing the offer/answer model, such as the Session protocol utilizing the offer/answer model, such as the Session
Initiation Protocol (SIP). Initiation Protocol (SIP).
+--------------------+-------------------------+-------+------------+ +--------------------+-------------------------+-------+------------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+--------------------+-------------------------+-------+------------+ +--------------------+-------------------------+-------+------------+
| ice-lite | Not Impacted | S | NORMAL | | ice-lite | Not Impacted | S | NORMAL |
| | | | | | | | | |
| ice-options | Not Impacted | S | NORMAL | | ice-options | Not Impacted | S | NORMAL |
| | | | | | | | | |
| ice-pwd | Per media-level | B | TRANSPORT | | ice-pwd | ice-pwd MUST be the one | B | TRANSPORT |
| | attribute MUST be used | | | | | that corresponds to the | | |
| | per underlying | | | | | m=line chosen for | | |
| | transport flow | | | | | setting up the | | |
| | underlying transport | | |
| | flow | | |
| | | | | | | | | |
| ice-ufrag | Per media-level | B | TRANSPORT | | ice-ufrag | ice-ufrag MUST be the | B | TRANSPORT |
| | attribute MUST be used | | | | | one that corresponds to | | |
| | per underlying | | | | | the m=line chosen for | | |
| | transport flow | | | | | setting up the | | |
| | underlying transport | | |
| | flow | | |
| | | | | | | | | |
| candidate | Per media-level | M | TRANSPORT | | candidate | ice candidate MUST be | M | TRANSPORT |
| | attribute MUST be used | | | | | the one that | | |
| | per underlying | | | | | corresponds to the | | |
| | transport flow | | | | | m=line chosen for | | |
| | setting up the | | |
| | underlying transport | | |
| | flow | | |
| | | | | | | | | |
| remote-candidates | Per media-level | M | TRANSPORT | | remote-candidates | ice remote candidate | M | TRANSPORT |
| | attribute MUST be used | | | | | MUST be the one that | | |
| | per underlying | | | | | corresponds to the | | |
| | transport flow | | | | | m=line chosen for | | |
| | setting up the | | |
| | underlying transport | | |
| | flow | | |
| | | | | | | | | |
+--------------------+-------------------------+-------+------------+ +--------------------+-------------------------+-------+------------+
RFC5245 Attribute Analysis RFC5245 Attribute Analysis
5.12. RFC5285 - RTP Header Extensions 5.12. RFC5285 - RTP Header Extensions
RFC5285 [RFC5285] provides a general mechanism to use the header RFC5285 [RFC5285] provides a general mechanism to use the header
extension feature of RTP (the Real-Time Transport Protocol). It extension feature of RTP (the Real-Time Transport Protocol). It
provides the option to use a small number of small extensions in each provides the option to use a small number of small extensions in each
skipping to change at page 17, line 15 skipping to change at page 17, line 33
5.13. RFC3605 - RTCP attribute in SDP 5.13. RFC3605 - RTCP attribute in SDP
Originally, SDP assumed that RTP and RTCP were carried on consecutive Originally, SDP assumed that RTP and RTCP were carried on consecutive
ports. However, this is not always true when NATs are involved. ports. However, this is not always true when NATs are involved.
[RFC3605] specifies an early mechanism to indicate the RTCP port. [RFC3605] specifies an early mechanism to indicate the RTCP port.
+-------+--------------------------------------+-------+------------+ +-------+--------------------------------------+-------+------------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+-------+--------------------------------------+-------+------------+ +-------+--------------------------------------+-------+------------+
| rtcp | Case1:Same RTCP port is repeated | M | TRANSPORT | | rtcp | Identical attribute value MUST be | M | IDENTICAL |
| | across the m=lines. Case2:Different | | | | | used since the RTCP port affects the | | |
| | RTCP ports renders multiplexing | | | | | entire RTP session. | | |
| | impossible | | |
| | | | | | | | | |
+-------+--------------------------------------+-------+------------+ +-------+--------------------------------------+-------+------------+
RFC3605 Attribute Analysis RFC3605 Attribute Analysis
5.14. RFC5576 - Source-Specific SDP Attributes 5.14. RFC5576 - Source-Specific SDP Attributes
RFC5576 [RFC5576] defines a mechanism to describe RTP media sources, RFC5576 [RFC5576] defines a mechanism to describe RTP media sources,
which are identified by their synchronization source (SSRC) which are identified by their synchronization source (SSRC)
identifiers, in SDP, to associate attributes with these sources, and identifiers, in SDP, to associate attributes with these sources, and
to express relationships among sources. It also defines several to express relationships among sources. It also defines several
source-level attributes that can be used to describe properties of source-level attributes that can be used to describe properties of
media sources. media sources.
+----------------+---------------------------+-------+--------------+ +----------------+-------------------------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+----------------+---------------------------+-------+--------------+ +----------------+-------------------------------+-------+----------+
| ssrc | | M | NOT | | ssrc | Refer to Notes below | M | SPECIAL |
| | | | RECOMMENDED | | | | | |
| | | | | | ssrc-group | Refer to section Section 9 | M | SPECIAL |
| ssrc-group | Refer to section | M | SPECIAL | | | for specific analysis of the | | |
| | Section 9 for specific | | | | | grouping semantics | | |
| | analysis of the grouping | | | | | | | |
| | semantics | | | | cname | Not Impacted [Open Issues: | SR | NORMAL |
| | | | | | | what are the rules for CNAME | | |
| cname | Not Impacted [Open | SR | NORMAL | | | duplication across | | |
| | Issues: what are the | | | | | sessions?] | | |
| | rules for CNAME | | | | | | | |
| | duplication across | | | | previous-ssrc | Refer to notes below | SR | SPECIAL |
| | sessions?] | | | | | | | |
| | | | | | fmtp | Not Impacted | SR | NORMAL |
| previous-ssrc | SSSRCs,if repeated across | SR | NOT | | | | | |
| | bundled m=lines, it MUST | | RECOMMENDED | +----------------+-------------------------------+-------+----------+
| | represent the same | | |
| | underlying RTP stream | | |
| | | | |
| fmtp | Not Impacted | SR | NORMAL |
| | | | |
+----------------+---------------------------+-------+--------------+
RFC5576 Attribute Analysis RFC5576 Attribute Analysis
If SSRCs are repeated across m=lines being multiplexed, they MUST all
represent the same underlying RTP Source. For more details on
implications of SSRC values with in the context of multiplexing
please refer to [I-D.ietf-mmusic-sdp-bundle-negotiation]
5.15. RFC6236 - Image Attributes in SDP 5.15. RFC6236 - Image Attributes in SDP
RFC6236 [RFC6236] proposes a new generic session setup attribute to RFC6236 [RFC6236] proposes a new generic session setup attribute to
make it possible to negotiate different image attributes such as make it possible to negotiate different image attributes such as
image size. A possible use case is to make it possible for a low-end image size. A possible use case is to make it possible for a low-end
hand-held terminal to display video without the need to rescale the hand-held terminal to display video without the need to rescale the
image,something that may consume large amounts of memory and image,something that may consume large amounts of memory and
processing power. The document also helps to maintain an optimal processing power. The document also helps to maintain an optimal
bitrate for video as only the image size that is desired by the bitrate for video as only the image size that is desired by the
receiver is transmitted. receiver is transmitted.
skipping to change at page 20, line 30 skipping to change at page 21, line 5
+----------+---------------+-------+----------+ +----------+---------------+-------+----------+
RFC4796 Attribute Analysis RFC4796 Attribute Analysis
5.20. RFC3407 - SDP Simple Capability Declaration 5.20. RFC3407 - SDP Simple Capability Declaration
RFC3407 [RFC3407] defines a set of Session Description Protocol (SDP) RFC3407 [RFC3407] defines a set of Session Description Protocol (SDP)
attributes that enables SDP to provide a minimal and backwards attributes that enables SDP to provide a minimal and backwards
compatible capability declaration mechanism. compatible capability declaration mechanism.
+----------+-------------------------------------+-------+----------+ +----------+----------------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+----------+-------------------------------------+-------+----------+ +----------+----------------------+-------+----------+
| sqn | Not Impacted | B | NORMAL | | sqn | Not Impacted | B | NORMAL |
| | | | | | | | | |
| csdc | Mismatch in the offered capability | B | TBD | | csdc | Not Impacted. | B | NORMAL |
| | description MAY fail multiplexing. | | | | | | | |
| | | | | | cpar | Refer to Section 15 | B | SPECIAL |
| cpar | Mismatch in the offered capability | B | TBD | | | | | |
| | parameters MAY fail multiplexing. | | | | cparmin | Refer to Section 15 | B | SPECIAL |
| | | | | | | | | |
| cparmin | Mismatch in the offered capability | B | TBD | | cparmax | Refer to Section 15 | B | SPECIAL |
| | parameters MAY fail multiplexing. | | | | | | | |
| | | | | +----------+----------------------+-------+----------+
| cparmax | Mismatch in the offered capability | B | TBD |
| | parameters MAY fail multiplexing. | | |
| | | | |
+----------+-------------------------------------+-------+----------+
RFC3407 Attribute Analysis RFC3407 Attribute Analysis
5.21. RFC6284 - Port Mapping between Unicast and Multicast RTP Sessions 5.21. RFC6284 - Port Mapping between Unicast and Multicast RTP Sessions
RFC6284 [RFC6284] presents a port mapping solution that allows RTP RFC6284 [RFC6284] presents a port mapping solution that allows RTP
receivers to choose their own ports for an auxiliary unicast session receivers to choose their own ports for an auxiliary unicast session
in RTP applications using both unicast and multicast services. The in RTP applications using both unicast and multicast services. The
solution provides protection against denial-of-service or packet solution provides protection against denial-of-service or packet
amplification attacks that could be used to cause one or more RTP amplification attacks that could be used to cause one or more RTP
skipping to change at page 22, line 4 skipping to change at page 22, line 21
+------------+---------------+-------+----------+ +------------+---------------+-------+----------+
RFC6714 Attribute Analysis RFC6714 Attribute Analysis
5.23. RFC4583 - SDP Format for BFCP Streams 5.23. RFC4583 - SDP Format for BFCP Streams
RFC4583 [RFC4583] document specifies how to describe Binary Floor RFC4583 [RFC4583] document specifies how to describe Binary Floor
Control Protocol (BFCP) streams in Session Description Protocol (SDP) Control Protocol (BFCP) streams in Session Description Protocol (SDP)
descriptions. User agents using the offer/answer model to establish descriptions. User agents using the offer/answer model to establish
BFCP streams use this format in their offers and answers BFCP streams use this format in their offers and answers
+------------+-------------------------------+-------+--------------+
| Name | Notes | Level | Category | +------------+---------------------------------+-------+------------+
+------------+-------------------------------+-------+--------------+ | Name | Notes | Level | Category |
| floorctrl | Must be repeated across all | M | IDENTICAL | +------------+---------------------------------+-------+------------+
| | the multiplexed m=lines | | | | floorctrl | Must be repeated across all the | M | IDENTICAL |
| | | | | | | multiplexed m=lines | | |
| confid | Not Impacted | M | NORMAL | | | | | |
| | | | | | confid | Not Impacted | M | NORMAL |
| userid | Not Impacted | M | NORMAL | | | | | |
| | | | | | userid | Not Impacted | M | NORMAL |
| floorid | The floorid MUST be unique | M | NOT | | | | | |
| | across the multiplexed | | RECOMMENDED | | floorid | The floorid MUST be globally | M | NORMAL |
| | m=lines | | | | | unique | | |
| | | | | | | | | |
+------------+-------------------------------+-------+--------------+ +------------+---------------------------------+-------+------------+
RFC4583 Attribute Analysis RFC4583 Attribute Analysis
5.24. RFC5547 - SDP Offer/Answer for File Transfer 5.24. RFC5547 - SDP Offer/Answer for File Transfer
RFC5547 [RFC5547] provides a mechanism to negotiate the transfer of RFC5547 [RFC5547] provides a mechanism to negotiate the transfer of
one or more files between two endpoints by using the Session one or more files between two endpoints by using the Session
Description Protocol (SDP) offer/answer model specified in [RFC3264]. Description Protocol (SDP) offer/answer model specified in [RFC3264].
+--------------------------------+---------------+-------+----------+ +----------------------+---------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+--------------------------------+---------------+-------+----------+ +----------------------+---------------+-------+----------+
| file-selector | Not Impacted | M | NORMAL | | file-selector | Not Impacted | M | NORMAL |
| | | | | | | | | |
| file-transfer-id | Not Impacted | M | NORMAL | | file-transfer-id | Not Impacted | M | NORMAL |
| | | | | | | | | |
| file-disposition | Not Impacted | M | NORMAL | | file-disposition | Not Impacted | M | NORMAL |
| | | | | | | | | |
| file-date,file-iconfile-range | Not Impacted | M | NORMAL | | file-date | Not Impacted | M | NORMAL |
| | | | | | | | | |
| file-iconfile-range | Not Impacted | M | NORMAL | | file-iconfile-range | Not Impacted | M | NORMAL |
| | | | | | | | | |
| file-iconfile-range | Not Impacted | M | NORMAL | +----------------------+---------------+-------+----------+
| | | | |
+--------------------------------+---------------+-------+----------+
RFC5547 Attribute Analysis RFC5547 Attribute Analysis
5.25. RFC6489 - SDP and RTP Media Loopback Extension 5.25. RFC6489 - SDP and RTP Media Loopback Extension
[MEDIA_LOOPBACK] adds new SDP media types and attributes, which [MEDIA_LOOPBACK] adds new SDP media types and attributes, which
enable establishment of media sessions where the media is looped back enable establishment of media sessions where the media is looped back
to the transmitter. Such media sessions will serve as monitoring and to the transmitter. Such media sessions will serve as monitoring and
troubleshooting tools by providing the means for measurement of more troubleshooting tools by providing the means for measurement of more
advanced VoIP, Real-time Text and Video over IP performance metrics. advanced VoIP, Real-time Text and Video over IP performance metrics.
skipping to change at page 24, line 5 skipping to change at page 24, line 24
RFC5760 Attribute Analysis RFC5760 Attribute Analysis
5.27. RFC3611 - RTCP XR 5.27. RFC3611 - RTCP XR
RFC3611 [RFC3611] defines the Extended Report (XR) packet type for RFC3611 [RFC3611] defines the Extended Report (XR) packet type for
the RTP Control Protocol (RTCP), and defines how the use of XR the RTP Control Protocol (RTCP), and defines how the use of XR
packets can be signaled by an application if it employs the Session packets can be signaled by an application if it employs the Session
Description Protocol (SDP). Description Protocol (SDP).
+----------+-----------------------------------+-------+------------+ +----------+---------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+----------+-----------------------------------+-------+------------+ +----------+---------------+-------+----------+
| rtcp-xr | The attribute MUST be reported | B | IDENTICAL | | rtcp-xr | Not Impacted | B | NORMAL |
| | across all m=lines multiplexed | | | | | | | |
| | | | | +----------+---------------+-------+----------+
+----------+-----------------------------------+-------+------------+
RFC3611 Attribute Analysis RFC3611 Attribute Analysis
5.28. RFC5939 - SDP Capability Negotiation 5.28. RFC5939 - SDP Capability Negotiation
RFC5939 [RFC5939] defines a general SDP Capability Negotiation RFC5939 [RFC5939] defines a general SDP Capability Negotiation
framework. It also specifies how to provide attributes and transport framework. It also specifies how to provide attributes and transport
protocols as capabilities and negotiate them using the framework. protocols as capabilities and negotiate them using the framework.
Extensions for other types of capabilities (e.g., media types and Extensions for other types of capabilities (e.g., media types and
media formats) may be provided in other documents. media formats) may be provided in other documents.
+-------+--------------------------------------+-------+------------+ +-------+-------------------------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+-------+--------------------------------------+-------+------------+ +-------+-------------------------------+-------+----------+
| pcfg | Depends on capability being | M | SPECIAL | | pcfg | Refer to section Section 15 | M | SPECIAL |
| | negotiated | | | | | | | |
| | | | | | acfg | Refer to section Section 15 | M | SPECIAL |
| acfg | Depends on capability being | M | SPECIAL | | | | | |
| | negotiated | | | | csup | Not Impacted | B | NORMAL |
| | | | | | | | | |
| csup | Depends on capability being | B | SPECIAL | | creq | Not Impacted | B | NORMAL |
| | negotiated | | | | | | | |
| | | | | | acap | Refer to section Section 15 | B | SPECIAL |
| creq | Depends on capability being | B | SPECIAL | | | | | |
| | negotiateds | | | | tcap | Refer to section Section 15 | B | SPECIAL |
| | | | | | | | | |
| acap | Depends on capability being | B | SPECIAL | +-------+-------------------------------+-------+----------+
| | negotiated | | |
| | | | |
| tcap | Repeat transport capability across | B | IDENTICAL |
| | all m= lines | | |
| | | | |
+-------+--------------------------------------+-------+------------+
RFC5939 Attribute Analysis RFC5939 Attribute Analysis
5.29. draft-ietf-mmusic-sdp-media-capabilities 5.29. RFC6781 - SDP Media Capabilities Negotiation
Session Description Protocol (SDP) capability negotiation provides a Session Description Protocol (SDP) capability negotiation provides a
general framework for indicating and negotiating capabilities in SDP. general framework for indicating and negotiating capabilities in SDP.
The base framework defines only capabilities for negotiating The base framework defines only capabilities for negotiating
transport protocols and attributes. [MEDIA_CAP] extends the transport protocols and attributes. [RFC6781] extends the framework
framework by defining media capabilities that can be used to by defining media capabilities that can be used to negotiate media
negotiate media types and their associated parameters. types and their associated parameters.
+--------+---------------+-------+----------+ +---------+------------------------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+--------+---------------+-------+----------+ +---------+------------------------------+-------+----------+
| rmcap | Not Impacted | B | NORMAL | | rmcap | Not Impacted | B | NORMAL |
| | | | | | | | | |
| omcap | Not Impacted | B | NORMAL | | omcap | Not Impacted | B | NORMAL |
| | | | | | | | | |
| mfcap | Not Impacted | B | NORMAL | | mfcap | Not Impacted | B | NORMAL |
| | | | | | | | | |
| mscap | Not Impacted | B | NORMAL | | mscap | Refer to section Section 15 | B | SPECIAL |
| | | | | | | | | |
| lcfg | Not Impacted | B | NORMAL | | lcfg | Refer to section Section 15 | B | SPECIAL |
| | | | | | | | | |
| secap | Not Impacted | S | NORMAL | | sescap | Not Impacted | S | NORMAL |
| | | | | | | | | |
+--------+---------------+-------+----------+ +---------+------------------------------+-------+----------+
draft-ietf-mmusic-sdp-media-capabilities Attribute Analysis draft-ietf-mmusic-sdp-media-capabilities Attribute Analysis
5.30. RFC4567 - Key Management Extensions for SDP and RTSP 5.30. RFC4567 - Key Management Extensions for SDP and RTSP
RFC4567 [RFC4567] defines general extensions for Session Description RFC4567 [RFC4567] defines general extensions for Session Description
Protocol (SDP) and Real Time Streaming Protocol (RTSP) to carry Protocol (SDP) and Real Time Streaming Protocol (RTSP) to carry
messages, as specified by a key management protocol, in order to messages, as specified by a key management protocol, in order to
secure the media. These extensions are presented as a framework, to secure the media. These extensions are presented as a framework, to
be used by one or more key management protocols. As such, their use be used by one or more key management protocols. As such, their use
skipping to change at page 26, line 20 skipping to change at page 26, line 41
defines a new SDP protocol identifier, 'TCP/TLS'. It also defines defines a new SDP protocol identifier, 'TCP/TLS'. It also defines
the syntax and semantics for an SDP 'fingerprint' attribute that the syntax and semantics for an SDP 'fingerprint' attribute that
identifies the certificate that will be presented for the TLS identifies the certificate that will be presented for the TLS
session. This mechanism allows media transport over TLS connections session. This mechanism allows media transport over TLS connections
to be established securely, so long as the integrity of session to be established securely, so long as the integrity of session
descriptions is assured. descriptions is assured.
+--------------+-------------------------------+-------+------------+ +--------------+-------------------------------+-------+------------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+--------------+-------------------------------+-------+------------+ +--------------+-------------------------------+-------+------------+
| fingerprint | Fingerprint value MUST be | B | IDENTICAL | | fingerprint | Fingerprint value from the | B | TRANSPORT |
| | identical across all the | | | | | m=line defining the | | |
| | m=lines | | | | | underlying transport is | | |
| | chosen | | |
| | | | | | | | | |
+--------------+-------------------------------+-------+------------+ +--------------+-------------------------------+-------+------------+
RFC4572 Attribute Analysis RFC4572 Attribute Analysis
5.32. RFC4570 - SDP Source Filters 5.32. RFC4570 - SDP Source Filters
RFC4570 [RFC4570] describes how to adapt the Session Description RFC4570 [RFC4570] describes how to adapt the Session Description
Protocol (SDP) to express one or more source addresses as a source Protocol (SDP) to express one or more source addresses as a source
filter for one or more destination "connection" addresses. It filter for one or more destination "connection" addresses. It
defines the syntax and semantics for an SDP "source-filter" attribute defines the syntax and semantics for an SDP "source-filter" attribute
that may reference either IPv4 or IPv6 address(es) as either an that may reference either IPv4 or IPv6 address(es) as either an
inclusive or exclusive source list for either multicast or unicast inclusive or exclusive source list for either multicast or unicast
destinations. In particular, an inclusive source-filter can be used destinations. In particular, an inclusive source-filter can be used
to specify a Source-Specific Multicast (SSM) session to specify a Source-Specific Multicast (SSM) session
+----------------+-----------------------------+-------+------------+ +----------------+-----------------------------+-------+------------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+----------------+-----------------------------+-------+------------+ +----------------+-----------------------------+-------+------------+
| source-filter | he attribute MUST be | B | IDENTICAL | | source-filter | The attribute MUST be | B | IDENTICAL |
| | repeated across all m=lines | | | | | repeated across all m=lines | | |
| | multiplexed | | | | | multiplexed | | |
| | | | | | | | | |
+----------------+-----------------------------+-------+------------+ +----------------+-----------------------------+-------+------------+
RFC4570 Attribute Analysis RFC4570 Attribute Analysis
5.33. RFC6128 - RTCP Port for Multicast Sessions 5.33. RFC6128 - RTCP Port for Multicast Sessions
The Session Description Protocol (SDP) has an attribute that allows The Session Description Protocol (SDP) has an attribute that allows
skipping to change at page 28, line 30 skipping to change at page 29, line 8
RFC4145 [RFC4145] describes how to express media transport over TCP RFC4145 [RFC4145] describes how to express media transport over TCP
using the Session Description Protocol (SDP). It defines the SDP using the Session Description Protocol (SDP). It defines the SDP
'TCP' protocol identifier, the SDP 'setup' attribute, which describes 'TCP' protocol identifier, the SDP 'setup' attribute, which describes
the connection setup procedure, and the SDP 'connection' attribute, the connection setup procedure, and the SDP 'connection' attribute,
which handles connection reestablishment. which handles connection reestablishment.
+-------------+--------------------------------+-------+------------+ +-------------+--------------------------------+-------+------------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+-------------+--------------------------------+-------+------------+ +-------------+--------------------------------+-------+------------+
| setup | Should be identical across all | B | IDENTICAL | | setup | MUST be identical across all | B | IDENTICAL |
| | m=lines | | | | | m=lines | | |
| | | | | | | | | |
| connection | Should be identical across all | B | IDENTICAL | | connection | MUST be identical across all | B | IDENTICAL |
| | m=lines | | | | | m=lines | | |
| | | | | | | | | |
+-------------+--------------------------------+-------+------------+ +-------------+--------------------------------+-------+------------+
RFC4145 Attribute Analysis RFC4145 Attribute Analysis
5.36. RFC5159 - OMA BCAST SDP Attributes 5.36. RFC5159 - OMA BCAST SDP Attributes
RFC5159 [RFC5159] provides descriptions of Session Description RFC5159 [RFC5159] provides descriptions of Session Description
Protocol (SDP) attributes used by the Open Mobile Alliance's Protocol (SDP) attributes used by the Open Mobile Alliance's
Broadcast Service and Content Protection specification. Broadcast Service and Content Protection specification.
+---------------------+-------+-------+----------+ +---------------------+---------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+---------------------+-------+-------+----------+ +---------------------+---------------+-------+----------+
| bcastversion | | S | TBD | | bcastversion | Not Impacted | S | NORMAL |
| | | | | | | | | |
| stkmstream | | B | TBD | | stkmstream | Not Impacted | B | NORMAL |
| | | | | | | | | |
| SRTPAuthentication | | M | TBD | | SRTPAuthentication | Not Impacted | M | NORMAL |
| | | | | | | | | |
| SRTPROCTxRate | | M | TBD | | SRTPROCTxRate | Not Impacted | M | NORMAL |
| | | | | | | | | |
+---------------------+-------+-------+----------+ +---------------------+---------------+-------+----------+
RFC5159 Attribute Analysis RFC5159 Attribute Analysis
5.37. RFC6193 - Media Description for IKE in SDP 5.37. RFC6193 - Media Description for IKE in SDP
RFC6193 [RFC6193] specifies how to establish a media session that RFC6193 [RFC6193] specifies how to establish a media session that
represents a virtual private network using the Session Initiation represents a virtual private network using the Session Initiation
Protocol for the purpose of on-demand media/application sharing Protocol for the purpose of on-demand media/application sharing
between peers. It extends the protocol identifier of the Session between peers. It extends the protocol identifier of the Session
Description Protocol (SDP) so that it can negotiate use of the Description Protocol (SDP) so that it can negotiate use of the
skipping to change at page 30, line 16 skipping to change at page 30, line 39
m=lines will use only one IPSec association for all of the m= lines. m=lines will use only one IPSec association for all of the m= lines.
5.38. RFC6064 - SDP and RTSP Extensions for 3GPP 5.38. RFC6064 - SDP and RTSP Extensions for 3GPP
The Packet-switched Streaming Service (PSS) and the Multimedia The Packet-switched Streaming Service (PSS) and the Multimedia
Broadcast/Multicast Service (MBMS) defined by 3GPP use the Session Broadcast/Multicast Service (MBMS) defined by 3GPP use the Session
Description Protocol (SDP) and Real Time Streaming Protocol (RTSP) Description Protocol (SDP) and Real Time Streaming Protocol (RTSP)
with some extensions. RFC6064 [RFC6064] provides information about with some extensions. RFC6064 [RFC6064] provides information about
these extensions and registers the RTSP and SDP extensions with IANA. these extensions and registers the RTSP and SDP extensions with IANA.
+-----------------------+----------------------+------+-------------+ +-------------------------------+------------+-------+--------------+
| Name | Notes | Leve | Category | | Name | Notes | Level | Category |
| | | l | | +-------------------------------+------------+-------+--------------+
+-----------------------+----------------------+------+-------------+ | X-predecbufsize | Refer to | M | NOT |
| X-predecbufsize | Case1:Aggregate | M | NOT | | | notes | | RECOMMENDED |
| | total when video | | RECOMMENDED | | | below | | |
| | m-lines are | | | | | | | |
| | muxed Case2:Multiple | | | | X-initpredecbufperiod | Refer to | M | NOT |
| | xing with audio | | | | | notes | | RECOMMENDED |
| | m=lines is invalid | | | | | below | | |
| | | | | | | | | |
| X-initpredecbufperiod | Case1:Aggregate | M | NOT | | X-initpostdecbufperiod | Refer to | M | NOT |
| | total when video | | RECOMMENDED | | | notes | | RECOMMENDED |
| | m-lines are | | | | | below | | |
| | muxed Case2:Multiple | | | | | | | |
| | xing with audio | | | | X-decbyterate | Refer to | M | NOT |
| | m=lines is invalid | | | | | notes | | RECOMMENDED |
| | | | | | | below | | |
| X-initpostdecbufperio | Case1:Aggregate | M | NOT | | | | | |
| d | total when video | | RECOMMENDED | | 3gpp-videopostdecbufsize | Refer to | M | NOT |
| | m-lines are | | | | | notes | | RECOMMENDED |
| | muxed Case2:Multiple | | | | | below | | |
| | xing with audio | | | | | | | |
| | m=lines is invalid | | | | framesize | Refer to | M | NOT |
| | | | | | | notes | | RECOMMENDED |
| X-decbyterate | Case1:Aggregate | M | NOT | | | below | | |
| | total when video | | RECOMMENDED | | | | | |
| | m-lines are | | | | 3GPP-Integrity-Key | Refer to | S | NOT |
| | muxed Case2:Multiple | | | | | notes | | RECOMMENDED |
| | xing with audio | | | | | below | | |
| | m=lines is invalid | | | | | | | |
| | | | | | 3GPP-SRTP-Config | Refer to | M | NOT |
| 3gpp-videopostdecbufs | Case1:Aggregate | M | NOT | | | notes | | RECOMMENDED |
| ize | total when video | | RECOMMENDED | | | below | | |
| | m-lines are muxed. | | | | | | | |
| | Case2:Multiplexing | | | | alt,alt-default-id | Refer to | M | NOT |
| | with audio m=lines | | | | | notes | | RECOMMENDED |
| | is invalid | | | | | below | | |
| | | | | | | | | |
| framesize | Not Impacted | M | NORMAL | | alt-group | Refer to | M | NOT |
| | | | | | | notes | | RECOMMENDED |
| 3GPP-Integrity-Key | Not Impacted | S | NORMAL | | | below | | |
| | | | | | | | | |
| 3GPP-SRTP-Config | Same config SHALL | M | NORMAL | | 3GPP-Adaptation-Support | Refer to | M | NOT |
| | apply to all the | | | | | notes | | RECOMMENDED |
| | m=lines multiplexed | | | | | below | | |
| | | | | | | | | |
| alt,alt-default-id | Specifying alternate | M | TBD | | 3GPP-Asset-Informatio | Refer to | B | NOT |
| | m=lines when session | | | | | notes | | RECOMMENDED |
| | with mulitple | | | | | below | | |
| | m=lines of different | | | | | | | |
| | types cannot be | | | | mbms-mode | Refer to | B | NOT |
| | clearly specified | | | | | notes | | RECOMMENDED |
| | | | | | | below | | |
| alt-group | Complicates | M | TBD | | | | | |
| | selection of | | | | mbms-flowid | MRefer to | M | NOT |
| | alternate m=lines | | | | | notes | | RECOMMENDED |
| | grouped with | | | | | below | | |
| | alt-group on | | | | | | | |
| | mulitplexing | | | | mbms-repair | Refer to | B | NOT |
| | | | | | | notes | | RECOMMENDED |
| 3GPP-Adaptation-Suppo | | M | TBD | | | below | | |
| rt | | | | | | | | |
| | | | | | 3GPP-QoE-Metrics:Corruption | Refer to | M | NOT |
| 3GPP-QoE-Metricsn | | B | TBD | | duration | notes | | RECOMMENDED |
| | | | | | | below | | |
| 3GPP-Asset-Informatio | | B | TBD | | | | | |
| | | | | | 3GPP-QoE-Metrics:Rebuffering | Refer to | M | NOT |
| | | | | | duration | notes | | RECOMMENDED |
| mbms-mode | | B | TBD | | | below | | |
| | | | | | | | | |
| mbms-flowid | Multiplexing | M | TBD | | 3GPP-QoE-Metrics:Initial | Refer to | M | NOT |
| | multiple m=lines | | | | buffering duration | notes | | RECOMMENDED |
| | complicates FEC | | | | | below | | |
| | mappings to the | | | | | | | |
| | transport | | | | 3GPP-QoE-Metrics:Successive | Refer to | M | NOT |
| | addresses. | | | | loss of RTP packets | notes | | RECOMMENDED |
| | | | | | | below | | |
| mbms-repair | | B | TBD | | | | | |
| | | | | | 3GPP-QoE-Metrics:Frame rate | Refer to | M | NOT |
+-----------------------+----------------------+------+-------------+ | deviation | notes | | RECOMMENDED |
| | below | | |
| | | | |
| 3GPP-QoE-Metrics:Jitter | Refer to | M | NOT |
| duration | notes | | RECOMMENDED |
| | below | | |
| | | | |
| 3GPP-QoE-Metrics:Content | Refer to | B | NOT |
| Switch Time | notes | | RECOMMENDED |
| | below | | |
| | | | |
| 3GPP-QoE-Metrics:Average | Refer to | M | NOT |
| Codec Bitrat | notes | | RECOMMENDED |
| | below | | |
| | | | |
| 3GPP-QoE-Metrics:Codec | Refer to | M | NOT |
| Information | notes | | RECOMMENDED |
| | below | | |
| | | | |
| 3GPP-QoE-Metrics:Buffer | Refer to | M | NOT |
| Status | notes | | RECOMMENDED |
| | below | | |
| | | | |
+-------------------------------+------------+-------+--------------+
RFC6064 Attribute Analysis RFC6064 Attribute Analysis
[RFC6064] defines SDP attributes that are applicable in the
declarative usage of SDP alone. For purposes of this document, only
the Offer/Answer usage of SDP is considered as mandated by
[I-D.ietf-mmusic-sdp-bundle-negotiation].
5.39. RFC3108 - ATM SDP 5.39. RFC3108 - ATM SDP
RFC3108 [RFC3108] describes conventions for using the Session RFC3108 [RFC3108] describes conventions for using the Session
Description Protocol (SDP) described for controlling ATM Bearer Description Protocol (SDP) described for controlling ATM Bearer
Connections, and any associated ATM Adaptation Layer (AAL) Connections, and any associated ATM Adaptation Layer (AAL)
+------------------------+--------------+-------+----------+ +------------------------+--------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+------------------------+--------------+-------+----------+ +------------------------+--------------+-------+----------+
| aalType | NOT IMPACTED | B | NORMAL | | aalType | Not Impacted | B | NORMAL |
| eecid | NOT IMPACTED | B | NORMAL | | eecid | Not Impacted | B | NORMAL |
| aalType | NOT IMPACTED | B | NORMAL | | aalType | Not Impacted | B | NORMAL |
| capability | NOT IMPACTED | B | NORMAL | | capability | Not Impacted | B | NORMAL |
| qosClass | NOT IMPACTED | B | NORMAL | | qosClass | Not Impacted | B | NORMAL |
| bcob | NOT IMPACTED | B | NORMAL | | bcob | Not Impacted | B | NORMAL |
| stc | NOT IMPACTED | B | NORMAL | | stc | Not Impacted | B | NORMAL |
| upcc | NOT IMPACTED | B | NORMAL | | upcc | Not Impacted | B | NORMAL |
| atmQOSparms | NOT IMPACTED | B | NORMAL | | atmQOSparms | Not Impacted | B | NORMAL |
| atmTrfcDesc | NOT IMPACTED | B | NORMAL | | atmTrfcDesc | Not Impacted | B | NORMAL |
| abrParms | NOT IMPACTED | B | NORMAL | | abrParms | Not Impacted | B | NORMAL |
| abrSetup | NOT IMPACTED | B | NORMAL | | abrSetup | Not Impacted | B | NORMAL |
| bearerType | NOT IMPACTED | B | NORMAL | | bearerType | Not Impacted | B | NORMAL |
| lij | NOT IMPACTED | B | NORMAL | | lij | Not Impacted | B | NORMAL |
| anycast | NOT IMPACTED | B | NORMAL | | anycast | Not Impacted | B | NORMAL |
| cache | NOT IMPACTED | B | NORMAL | | cache | Not Impacted | B | NORMAL |
| bearerSigIE | NOT IMPACTED | B | NORMAL | | bearerSigIE | Not Impacted | B | NORMAL |
| aalApp | NOT IMPACTED | B | NORMAL | | aalApp | Not Impacted | B | NORMAL |
| cbrRate | NOT IMPACTED | B | NORMAL | | cbrRate | Not Impacted | B | NORMAL |
| sbc | NOT IMPACTED | B | NORMAL | | sbc | Not Impacted | B | NORMAL |
| clkrec | NOT IMPACTED | B | NORMAL | | clkrec | Not Impacted | B | NORMAL |
| fec | NOT IMPACTED | B | NORMAL | | fec | Not Impacted | B | NORMAL |
| prtfl | NOT IMPACTED | B | NORMAL | | prtfl | Not Impacted | B | NORMAL |
| structure | NOT IMPACTED | B | NORMAL | | structure | Not Impacted | B | NORMAL |
| cpsSDUsize | NOT IMPACTED | B | NORMAL | | cpsSDUsize | Not Impacted | B | NORMAL |
| aal2CPS | NOT IMPACTED | B | NORMAL | | aal2CPS | Not Impacted | B | NORMAL |
| aal2CPSSDUrate | NOT IMPACTED | B | NORMAL | | aal2CPSSDUrate | Not Impacted | B | NORMAL |
| aal2sscs3661unassured | NOT IMPACTED | B | NORMAL | | aal2sscs3661unassured | Not Impacted | B | NORMAL |
| aal2sscs3661assured | NOT IMPACTED | B | NORMAL | | aal2sscs3661assured | Not Impacted | B | NORMAL |
| aal2sscs3662 | NOT IMPACTED | B | NORMAL | | aal2sscs3662 | Not Impacted | B | NORMAL |
| aal5sscop | NOT IMPACTED | B | NORMAL | | aal5sscop | Not Impacted | B | NORMAL |
| atmmap | NOT IMPACTED | B | NORMAL | | atmmap | Not Impacted | B | NORMAL |
| silenceSupp | NOT IMPACTED | B | NORMAL | | silenceSupp | Not Impacted | B | NORMAL |
| ecan | NOT IMPACTED | B | NORMAL | | ecan | Not Impacted | B | NORMAL |
| gc | NOT IMPACTED | B | NORMAL | | gc | Not Impacted | B | NORMAL |
| profileDesc | NOT IMPACTED | B | NORMAL | | profileDesc | Not Impacted | B | NORMAL |
| vsel | NOT IMPACTED | B | NORMAL | | vsel | Not Impacted | B | NORMAL |
| dsel | NOT IMPACTED | B | NORMAL | | dsel | Not Impacted | B | NORMAL |
| fsel | NOT IMPACTED | B | NORMAL | | fsel | Not Impacted | B | NORMAL |
| onewaySel | NOT IMPACTED | B | NORMAL | | onewaySel | Not Impacted | B | NORMAL |
| codecconfig | NOT IMPACTED | B | NORMAL | | codecconfig | Not Impacted | B | NORMAL |
| isup_usi | NOT IMPACTED | B | NORMAL | | isup_usi | Not Impacted | B | NORMAL |
| isup_usi | NOT IMPACTED | B | NORMAL | | isup_usi | Not Impacted | B | NORMAL |
| chain | NOT IMPACTED | B | NORMAL | | chain | Not Impacted | B | NORMAL |
| | | | | | | | | |
+------------------------+--------------+-------+----------+ +------------------------+--------------+-------+----------+
RFC3108 Attribute Analysis RFC3108 Attribute Analysis
RFC3108 describes conventions for using the Session Description RFC3108 describes conventions for using the Session Description
Protocol (SDP) for characterizing ATM bearer connections using an Protocol (SDP) for characterizing ATM bearer connections using an
AAL1, AAL2 or AAL5 adaptation layers. For AAL1, AAL2 and AAL5, AAL1, AAL2 or AAL5 adaptation layers. For AAL1, AAL2 and AAL5,
bearer connections can be used to transport single media streams. In bearer connections can be used to transport single media streams. In
addition, for AAL1 and AAL2, multiple media streams may be addition, for AAL1 and AAL2, multiple media streams may be
skipping to change at page 37, line 11 skipping to change at page 38, line 11
| path | Not Impacted | M | NORMAL | | path | Not Impacted | M | NORMAL |
| | | | | | | | | |
+-----------------------+---------------+-------+----------+ +-----------------------+---------------+-------+----------+
RFC4975 Attribute Analysis RFC4975 Attribute Analysis
5.46. Historical 5.46. Historical
This section specifies analysis for the attributes that are included This section specifies analysis for the attributes that are included
for historic usage alone by the [IANA]. for historic usage alone by the [IANA].
+---------------------+-----------------+---------------+----------+ +---------------------+--------------+---------------+--------------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+---------------------+-----------------+---------------+----------+ +---------------------+--------------+---------------+--------------+
| rtpred1 | Not Applicable | Not-Applcable | TBD | | rtpred1 | Historic | Not-Applcable | NOT |
| | | | | | | attributes. | | RECOMMENDED |
| rtpred2 | Not Applicable | Not-Applcable | TBD | | | | | |
| | | | | | rtpred2 | Historic | Not-Applcable | NOT |
| PSCid | Not Applicable | Not-Applcable | TBD | | | attributes. | | RECOMMENDED |
| | | | | | | | | |
| bc_service | Not Applicable | Not-Applcable | TBD | | PSCid | Not | Not-Applcable | TBD |
| | | | | | | Applicable | | |
| bc_program | Not Applicable | Not-Applcable | TBD | | | | | |
| | | | | | bc_service | Not | Not-Applcable | TBD |
| bc_service_package | Not Applicable | Not-Applcable | TBD | | | Applicable | | |
| | | | | | | | | |
+---------------------+-----------------+---------------+----------+ | bc_program | Not | Not-Applcable | TBD |
| | Applicable | | |
| | | | |
| bc_service_package | Not | Not-Applcable | TBD |
| | Applicable | | |
| | | | |
+---------------------+--------------+---------------+--------------+
Unknowns Attribute Analysis Unknowns Attribute Analysis
6. bwtype Attribute Analysis 6. bwtype Attribute Analysis
This section specifies handling of specific bandwidth attributes when This section specifies handling of specific bandwidth attributes when
used in multiplexing scenarios. used in multiplexing scenarios.
6.1. RFC4566 - SDP: Session Description Protocol 6.1. RFC4566 - SDP: Session Description Protocol
+------------+-----------------------------------+-------+----------+ +------------+-----------------------------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+------------+-----------------------------------+-------+----------+ +------------+-----------------------------------+-------+----------+
| bwtype:CT | Aggregate bandwidth for the | S | NORMAL | | bwtype:CT | Aggregate bandwidth for the | S | NORMAL |
| | conference | | | | | conference | | |
| | | | | | | | | |
| bwtype:AS | There are 2 interpretations for | B | NORMAL, | | bwtype:AS | As a session attribute, it | B | NORMAL |
| | this attribute As a session | | SUM | | | specifies the session aggregate | | |
| | attribute, it specifies the | | | | | unless media-level b=RR and/or | | |
| | session aggregate unless | | | | | b=RS attributes are used. Under | | |
| | media-level b=RR and/or b=RS | | | | | this interpretation the | | |
| | attributes are used. Under this | | | | | multiplexing scheme has no impact | | |
| | interpretation the multiplexing | | | | | and thus NORMAL category | | |
| | scheme has no impact and belongs | | | | | applies. | | |
| | to NORMAL category. For the | | | | | | | |
| | media level usage, the aggregate | | | | bwtype:AS | For the media level usage,the | B | SUM |
| | of individual bandwidth values is | | | | | aggregate of individual bandwidth | | |
| | considered. | | | | | values is considered. | | |
| | | | | | | | | |
+------------+-----------------------------------+-------+----------+ +------------+-----------------------------------+-------+----------+
RFC4566 bwtype Analysis RFC4566 bwtype Analysis
6.2. RFC3556 - SDP Bandwidth Modifiers for RTCP Bandwidth 6.2. RFC3556 - SDP Bandwidth Modifiers for RTCP Bandwidth
RFC3556 [RFC3556] defines an extension to the Session Description RFC3556 [RFC3556] defines an extension to the Session Description
Protocol (SDP) to specify two additional modifiers for the bandwidth Protocol (SDP) to specify two additional modifiers for the bandwidth
attribute. These modifiers may be used to specify the bandwidth attribute. These modifiers may be used to specify the bandwidth
allowed for RTP Control Protocol (RTCP) packets in a Real-time allowed for RTP Control Protocol (RTCP) packets in a Real-time
Transport Protocol (RTP) session Transport Protocol (RTP) session
+------------+--------------------------------+-------+-------------+ +------------+--------------------------------+-------+-------------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+------------+--------------------------------+-------+-------------+ +------------+--------------------------------+-------+-------------+
| bwtype:RS | S level usage represents | B | NORMAL,SUM | | bwtype:RS | Session level usage represents | B | NORMAL,SUM |
| | session aggregate and media | | | | | session aggregate and media | | |
| | level usage indicates SUM of | | | | | level usage indicates SUM of | | |
| | the individual values while | | | | | the individual values while | | |
| | multiplexing | | | | | multiplexing | | |
| | | | | | | | | |
| bwtype:RR | S level usage represents | B | NORMAL,SUM | | bwtype:RR | Session level usage represents | B | NORMAL,SUM |
| | session aggregate and media | | | | | session aggregate and media | | |
| | level usage indicates SUM of | | | | | level usage indicates SUM of | | |
| | the individual values while | | | | | the individual values while | | |
| | multiplexing | | | | | multiplexing | | |
| | | | | | | | | |
+------------+--------------------------------+-------+-------------+ +------------+--------------------------------+-------+-------------+
RFC3556 bwtype Analysis RFC3556 bwtype Analysis
6.3. RFC3890 - Bandwidth Modifier for SDP 6.3. RFC3890 - Bandwidth Modifier for SDP
skipping to change at page 39, line 18 skipping to change at page 40, line 22
Transport Independent Application Specific Maximum (TIAS) bandwidth Transport Independent Application Specific Maximum (TIAS) bandwidth
modifier that does not include transport overhead; instead an modifier that does not include transport overhead; instead an
additional packet rate attribute is defined. The transport additional packet rate attribute is defined. The transport
independent bit-rate value together with the maximum packet rate can independent bit-rate value together with the maximum packet rate can
then be used to calculate the real bit-rate over the transport then be used to calculate the real bit-rate over the transport
actually used. actually used.
+--------------+---------------------------------+-------+----------+ +--------------+---------------------------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+--------------+---------------------------------+-------+----------+ +--------------+---------------------------------+-------+----------+
| bwtype:TIAS | The usage of TIAS is not | B | TBD | | bwtype:TIAS | The usage of TIAS is not | B | SPECIAL |
| | clearly defined Offer/Answer | | | | | clearly defined Offer/Answer | | |
| | usage. | | | | | usage. | | |
| | | | | | | | | |
| maxprate | The usage of TIAS and maxprate | B | TBD | | maxprate | The usage of TIAS and maxprate | B | SPECIAL |
| | is not well defined under | | | | | is not well defined under | | |
| | multiplexing | | | | | multiplexing | | |
| | | | | | | | | |
+--------------+---------------------------------+-------+----------+ +--------------+---------------------------------+-------+----------+
RFC3890 bwtype Analysis RFC3890 bwtype Analysis
The intention of TIAS is that the media level bit-rate is multiplied The intention of TIAS is that the media level bit-rate is multiplied
with the known per-packet overhead for the selected transport and the with the known per-packet overhead for the selected transport and the
maxprate value to determine the worst case bit-rate from the maxprate value to determine the worst case bit-rate from the
skipping to change at page 43, line 40 skipping to change at page 45, line 5
RFC3524 Attribute Analysis RFC3524 Attribute Analysis
8.3. RFC4091 - ANAT Semantics 8.3. RFC4091 - ANAT Semantics
RFC4091 [RFC4091] defines the Alternative Network Address Types RFC4091 [RFC4091] defines the Alternative Network Address Types
(ANAT) semantics for the Session Description Protocol (SDP) grouping (ANAT) semantics for the Session Description Protocol (SDP) grouping
framework. The ANAT semantics allow alternative types of network framework. The ANAT semantics allow alternative types of network
addresses to establish a particular media stream. addresses to establish a particular media stream.
+-------------+----------------+-------+------------------+ +-------------+---------------------------+-------+-----------------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+-------------+----------------+-------+------------------+ +-------------+---------------------------+-------+-----------------+
| group:ANAT | Not Impacted | S | NOT RECOMMENDED | | group:ANAT | ANAT semantics is | S | NOT |
| | | | | | | obseleted | | RECOMMENDED |
+-------------+----------------+-------+------------------+ | | | | |
+-------------+---------------------------+-------+-----------------+
RFC4091 Attribute Analysis RFC4091 Attribute Analysis
8.4. RFC5956 - FEC Grouping Semantics in SDP 8.4. RFC5956 - FEC Grouping Semantics in SDP
RFC5956 [RFC5956] defines the semantics for grouping the associated RFC5956 [RFC5956] defines the semantics for grouping the associated
source and FEC-based (Forward Error Correction) repair flows in the source and FEC-based (Forward Error Correction) repair flows in the
Session Description Protocol (SDP). The semantics defined in the Session Description Protocol (SDP). The semantics defined in the
document are to be used with the SDP Grouping Framework (RFC 5888). document are to be used with the SDP Grouping Framework (RFC 5888).
These semantics allow the description of grouping relationships These semantics allow the description of grouping relationships
skipping to change at page 44, line 36 skipping to change at page 45, line 46
8.5. RFC5583 - Signaling Media Decoding Dependency in SDP 8.5. RFC5583 - Signaling Media Decoding Dependency in SDP
RFC5583 [RFC5583] defines semantics that allow for signaling the RFC5583 [RFC5583] defines semantics that allow for signaling the
decoding dependency of different media descriptions with the same decoding dependency of different media descriptions with the same
media type in the Session Description Protocol (SDP). This is media type in the Session Description Protocol (SDP). This is
required, for example, if media data is separated and transported in required, for example, if media data is separated and transported in
different network streams as a result of the use of a layered or different network streams as a result of the use of a layered or
multiple descriptive media coding process. multiple descriptive media coding process.
+-------------+---------------+-------+----------+ +-------------+----------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+-------------+---------------+-------+----------+ +-------------+----------------+-------+----------+
| depend lay | Not Impacted | M | NORMAL | | depend lay | Not Impacted | M | NORMAL |
| | | | | | | | | |
| depend mdc | Not Impacted | M | NORMAL | | depend mdc | Not Impacted | M | NORMAL |
| | | | | | | | | |
+-------------+---------------+-------+----------+ +-------------+----------------+-------+----------+
RFC5583 Attribute Analysis RFC5583 Attribute Analysis
If the Payload Type is not unique across the bundled m=lines, it MUST The usage of identical Payload Type values across multiplexed m=lines
represent the same Codec-Configuration. is described in [I-D.ietf-mmusic-sdp-bundle-negotiation].
9. ssrc-group Attribute Analysis 9. ssrc-group Attribute Analysis
This section analyzes "ssrc-group" semantics [SSRC-GROUP]. This section analyzes "ssrc-group" semantics [SSRC-GROUP].
9.1. RFC5576 - Source-Specific SDP Attributes 9.1. RFC5576 - Source-Specific SDP Attributes
+---------+---------------+-------+----------+ +---------+---------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+---------+---------------+-------+----------+ +---------+---------------+-------+----------+
skipping to change at page 46, line 18 skipping to change at page 47, line 21
+------+------------------------------------+-------+---------------+ +------+------------------------------------+-------+---------------+
| k= | It is NOT recommended to use this | S | NOT | | k= | It is NOT recommended to use this | S | NOT |
| | attribute | | RECOMMENDED | | | attribute | | RECOMMENDED |
| | | | | | | | | |
+------+------------------------------------+-------+---------------+ +------+------------------------------------+-------+---------------+
RFC4566 Attribute Analysis RFC4566 Attribute Analysis
12. content Atribute Analysis 12. content Atribute Analysis
12.1. RFC4796 - MSRP Relays 12.1. RFC4796
+------------------+---------------+-------+----------+ +------------------+---------------+-------+----------+
| Name | Notes | Level | Category | | Name | Notes | Level | Category |
+------------------+---------------+-------+----------+ +------------------+---------------+-------+----------+
| content:slides | Not Impacted | M | NORMAL | | content:slides | Not Impacted | M | NORMAL |
| | | | | | | | | |
| content:speaker | Not Impacted | M | NORMAL | | content:speaker | Not Impacted | M | NORMAL |
| | | | | | | | | |
| content:main | Not Impacted | M | NORMAL | | content:main | Not Impacted | M | NORMAL |
| | | | | | | | | |
skipping to change at page 47, line 45 skipping to change at page 48, line 47
a proposal to the WG. There are two options being proposed, A and B. a proposal to the WG. There are two options being proposed, A and B.
The authors suggest A. The authors suggest A.
14.1. Option A 14.1. Option A
This section provides two rules for multiplexing multiple media This section provides two rules for multiplexing multiple media
streams with DSCP markings over a single 5-tuple. streams with DSCP markings over a single 5-tuple.
Rule 1: Media Streams with markings from different service classes Rule 1: Media Streams with markings from different service classes
MUST NOT be multiplexed. For example, a media stream with DSCP MUST NOT be multiplexed. For example, a media stream with DSCP
Marking EF MUST NOT be multiplexed with a media stream marked with Marking EF MUST NOT be multiplexed with a media stream marked with
AF class. Likewise, a media stream with DSCP marking AF3X MUST AF class. Likewise, a media stream with DSCP marking AF3x MUST
NOT be multiplexed with a media stream marked with AF4X. NOT be multiplexed with a media stream marked with AF4x.
Rule 2: Media Streams that belong to the same service class, even Rule 2: Media Streams that belong to the same service class, even
with different drop precedence, MAY be multiplexed. Thus media with different drop precedence, MAY be multiplexed. Thus media
streams that all belong to the EF group or all that belong to the streams that all belong to the EF group or all that belong to the
AF4X class can be multiplexed. AF4X class can be multiplexed.
For WebRTC applications following the advice in For WebRTC applications following the advice in
[I-D.dhesikan-tsvwg-rtcweb-qos], the above rules end up allowing the [I-D.dhesikan-tsvwg-rtcweb-qos], the above rules end up allowing the
audio and video to be multiplexed in many, but not all, cases. audio and video to be multiplexed in many, but not all, cases.
14.2. Option B 14.2. Option B
Media Streams MAY be multiplexed regardless of their DSCP service Media Streams MAY be multiplexed regardless of what the setting of
class markings. the DSCP Per Hop Behavior group (PHB).
15. IANA Considerations 15. Multiplexing Considerations for Encapsulating Attributes
NOTE: The analysis given below is still Work-In-Progress and will be
updated soon.
This sections deals with recommendations for defining the
multiplexing charactersitics of the SDP attributes that encaspsulate
other SDP attributes. Such attributes as of today, for example, are
defined in [RFC3407], [RFC5939] and [RFC6781] as part of a generic
framework for indicating and negotiating transport, media and media
format related capabilities in the SDP.
The behavior of such attributes under multiplexing is in turn defined
by the multiplexing behavior of the attributes they encapsulate which
are made known once the negotiation process is completed.
Example 1: Below SDP example captures the following aspects.
1. The Offerer offers audio and video streams with several different
RTP profiles (AVP, SAVP, SAVPF) as potential configurations.
2. ANSWER - 1 corresponds to the SDP answer where the Answerer
accepts RTP/SAVPF as the default profile for both the media
streams. In this scenario both the media streams can be
successfully multiplexed.
3. In ANSWER - 2 SDP, the Answerer accepts the profile RTP/SAVPF for
the audio stream and RTP/AVPF for the video stream. This
scenario results in the failure of the multiplexing as defined in
the section 7.2 of the BUNDLE specifcation
[I-D.ietf-mmusic-sdp-bundle-negotiation].
v=0
o=- 25678 753849 IN IP4 192.0.2.1
s=
t=0 0
c=IN IP4 192.0.2.1
m=audio 3456 RTP/AVP 98
a=tcap:1 RTP/SAVPF
a=rtpmap:98 OPUS/48000/2
a=pcfg:1 t=1
m=video 51372 RTP/AVP 101
a=rtpmap:101 H264/90000
a=tcap:2 RTP/SAVPF RTP/AVPF
a=pcfg:2 t=2|3
ANSWER - 1
-----------
v=0
o=- 24351 621814 IN IP4 192.0.2.2
s=
m=audio 3456 RTP/SAVPF 98
a=rtpmap:98 OPUS/48000/2
a=acfg:1 t=1
m=video 51372 RTP/SAVPF 101
a=rtpmap:101 H264/90000
a=acfg:2 t=2
ANSWER - 2
-----------
v=0
o=- 24351 621814 IN IP4 192.0.2.2
s=
m=audio 3456 RTP/SAVPF 98
a=rtpmap:98 OPUS/48000/2
a=acfg:1 t=1
m=video 51372 RTP/AVPF 101
a=rtpmap:101 H264/90000
a=acfg:2 t=3
Example 2: Below SDP example captures the following aspects.
1. Offerer offers use of plain RTP and Secure RTP as alternatives.
For the Secure RTP stream, it can be established using either
DTLS-SRTP or SDP security descriptions
2. ANSWER - 1 corresponds to the SDP answer where the Answerer
accepts DTLS based encryption for both the audio and video
streams. This scenario can lead to successfull multiplexing of
the audio and the video streams.
3. In ANSWER - 2 SDP, the Answerer accepts plain RTP for the audio
stream and DTLS based encryption for the video stream. This
scenario results in unsuccesfull multiplexing of the media
streams since the encryption scheme applies to the entire RTP
Session and cannot be applied to video media stream alone when
multiplexed.
OFFER
-----
v=0
o=- 25678 753849 IN IP4 192.0.2.1
s=
t=0 0
c=IN IP4 192.0.2.1
a=acap:1 setup:actpass
a=acap:2 fingerprint: SHA-1 \
4A:AD:B9:B1:3F:82:18:3B:54:02:12:DF:3E:5D:49:6B:19:E5:7C:AB
a=tcap:1 UDP/TLS/RTP/SAVP RTP/SAVP
m=audio 59000 RTP/AVP 98
a=rtpmap:98 AMR/8000
a=acap:3 crypto:1 AES_CM_128_HMAC_SHA1_32
inline:NzB4d1BINUAvLEw6UzF3WSJ+PSdFcGdUJShpX1Zj|2^20|1:32
a=pcfg:1 t=1 a=1,2
a=pcfg:2 t=2 a=3
m=video 59123 RTP/AVP 100
a=rtpmap:100 VP8/90000
a=pcfg:3 t=1 a=1,2
ANSWER - 1
-----------
v=0
o=- 24351 621814 IN IP4 192.0.2.2
s=
t=0 0
c=IN IP4 192.0.2.2
m=audio 54568 UDP/TLS/RTP/SAVP 98
a=rtpmap:98 AMR/8000
a=acfg:1 t=1 a=1,2
m=video 54968 UDP/TLS/RTP/SAVP 100
a=rtpmap:100 VP8/90000
a=acfg:3 t=1 a=1,2
ANSWER - 2
-----------
v=0
o=- 24351 621814 IN IP4 192.0.2.2
s=
t=0 0
c=IN IP4 192.0.2.2
m=audio 54568 RTP/AVP 98
a=rtpmap:98 AMR/8000
m=video 54968 UDP/TLS/RTP/SAVP 100
a=rtpmap:100 VP8/90000
a=setup:active
a=fingerprint: SHA-1 \
FF:FF:FF:B1:3F:82:18:3B:54:02:12:DF:3E:5D:49:6B:19:E5:7C:AB
a=acfg:3 t=1 a=1,2
In conclusion, the mutliplexing behavior of the encapsulating
attributes are defined based on the multiplexing behavior of the
attributes they encapsulate. Thus care should be taken in
determining if certain combinations of these attributes can be used
in the context of transport multplexing.
16. IANA Considerations
IANA shall register categories from this specification by expanding IANA shall register categories from this specification by expanding
the Session Description Protocol (SDP) Parameters table with a column the Session Description Protocol (SDP) Parameters table with a column
listing categories against each SDP parameter. listing categories against each SDP parameter.
+---------------------+ +---------------------+
| Category | | Category |
+---------------------+ +---------------------+
| NORMAL | | NORMAL |
+---------------------+ +---------------------+
| NOT RECOMMENDED | | NOT RECOMMENDED |
+---------------------+ +---------------------+
| IDENTICAL | | IDENTICAL |
+---------------------+ +---------------------+
| TRANSPORT | | TRANSPORT |
+---------------------+ +---------------------+
| SPECIAL | | SPECIAL |
---------------------- ----------------------
16. Security Considerations 17. Security Considerations
All the attributes which involve security key needs a careful review All the attributes which involve security key needs a careful review
to ensure two-time pad vulnerability is not created to ensure two-time pad vulnerability is not created.
17. Acknowledgments 18. Acknowledgments
I would like to thank Cullen Jennings for suggesting the categories, I would like to thank Cullen Jennings for suggesting the categories,
contributing text and helping review the draft. I would also link to contributing text and reviewing the draft. I would also link to
thank Magnus, Christer and Dan on suggesting structural changes thank Magnus, Christer and Dan on suggesting structural changes
helping improve the document readability. helping improve the document readability.
I would like also to thank following experts on their inputs and I would like also to thank following experts on their inputs and
reviews as listed - Rohan Mahy(5.45), Eric Burger(5.22), Christian reviews as listed - Flemming Andreasen(5.20,5.28,5.29,15), Rohan
Huitema(5.13), Christer Holmberg(5.22,5.40,5.41), Richard Ejzak Mahy(5.45), Eric Burger(5.22),Christian Huitema(5.13), Christer
(5.36,5.42,5.43,5.44,), Colin Perkins(5.7,5.8), Magnus Holmberg(5.17,5.22,5.40,5.41), Richard Ejzak (5.36,5.42,5.43,5.44),
westerlund(5.3,5.9,6.1,6.2,6.3,8.3,5.2,7,8,9), Roni Colin Perkins(5.7,5.8), Magnus westerlund(5.2,5.3,5.9,5.26,
Evens(5.12,5.27,8.4), Subha Dhesikan(5.5,12.1,14), Dan 5.27,6.1,6.2,6.3,8.3,7), Roni Evens(5.12,5.27,8.4), Subha
Wing(5.6,5.11,5.30,5.34,5.37), Ali C Dhesikan(5.5,12.1,14), Dan Wing(5.6,5.11,5.30,5.34,5.37), Ali C
Begen(5.1,5.16,5.18,5.21,5.33,8.2,13.1,10.4,15.1), Bo Burman Begen(5.1,5.16,5.18,5.21,5.33,8.2,8.4,13.1), Bo Burman (7.2,7.6),
(7.2,7.6), Charles Eckel(5.14,5.23,5.24,10.5), Paul Kyzivat(5.24), Charles Eckel(5.14,5.23,5.24,9.1,8.5), Paul Kyzivat(5.24), Ian
Ian Johansson (5.11), Saravanan Shanmugham(5.10), Paul E Jones(5.25), Johansson(5.15), Saravanan Shanmugham(5.10), Paul E Jones(5.25),
Rajesh Kumar (5.39), Jonathan Lennox (5.31,5,14,11.1), Mo Rajesh Kumar(5.39), Jonathan Lennox(5.31,5,14,11.1), Mo
Zanaty(5.4,5.19,10.1,10.5), David Black (14) Zanaty(5.4,5.19,8.1,8.3,8.5,12.1), Christian Huitema (5.13), Qin Wu
(5.38 PM-Dir review).
18. Change Log 19. Change Log
[RFC EDITOR NOTE: Please remove this section when publishing] [RFC EDITOR NOTE: Please remove this section when publishing]
Changes from draft-ietf-mmusic-sdp-mux-attributes-00
o Added Section 15 to provide recommendations on multiplexing SDP
encapsulating attributes. Also updated sections 5.20, 5.28, 5.29
to refer to Section 15.
o Updated Section 5.38 to incorporate PM-dir review inputs from Qin
Wu
o Updated Sections 5.2,5.14,8.5 to refer to BUNDLE draft for more
clarity.
o Fixed few nits regarding sentence clarity and fill-in the NOTES
section where information was lacking.
Changes from draft-nandakumar-mmusic-mux-attributes-05 Changes from draft-nandakumar-mmusic-mux-attributes-05
o Renamed the document to be a WG document. o Renamed the document to be a WG document.
o Added Section 14. o Added Section 14.
o Updated Open Issues based on IETF88 discussions. o Updated Open Issues based on IETF88 discussions.
Changes from draft-nandakumar-mmusic-mux-attributes-04 Changes from draft-nandakumar-mmusic-mux-attributes-04
o Added few OPEN ISSUES that needs to be discussed. o Added few OPEN ISSUES that needs to be discussed.
o Updated sections 5.10,5.23,5,24,5,25,7.2,9.1,5.12,5.27,8.4, o Updated sections 5.10,5.23,5,24,5,25,7.2,9.1,5.12,5.27,8.4,
5.44,5.11,5.4,5.19,10.1,10.5,5.21,10.4,15.1 5.44,5.11,5.4,5.19,10.1,10.5,5.21,10.4,15.1
o Updated Table Column name Current to Level and improved TRANSPORT o Updated Table Column name Current to Level and improved TRANSPORT
category explanation on suggestions form Dan Wing. category explanation on suggestions form Dan Wing.
o Grouped all the rtcp-fb attribute analysis under a single section o Grouped all the rtcp-fb attribute analysis under a single section
as suggested by Magnus/ as suggested by Magnus/
skipping to change at page 49, line 47 skipping to change at page 54, line 32
the inputs from the respective RFC Authors. the inputs from the respective RFC Authors.
Changes from draft-nandakumar-mmusic-mux-attributes-01 Changes from draft-nandakumar-mmusic-mux-attributes-01
o Replaced Category BAD with NOT RECOMMENDED. o Replaced Category BAD with NOT RECOMMENDED.
o Added Category TBD. o Added Category TBD.
o Updated IANA Consideration Section. o Updated IANA Consideration Section.
Changes from draft-nandakumar-mmusic-mux-attributes-00 Changes from draft-nandakumar-mmusic-mux-attributes-00
o Added new section for dealing with FEC payload types. o Added new section for dealing with FEC payload types.
19. References 20. References
19.1. Normative References
20.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
Description Protocol", RFC 4566, July 2006. Description Protocol", RFC 4566, July 2006.
19.2. Informative References 20.2. Informative References
[ACK-NACK] [ACK-NACK]
"S Description Protocol (SDP) RTCP ACK/NACK Feedback "S Description Protocol (SDP) RTCP ACK/NACK Feedback
attributes", <http://www.iana.org/assignments/ attributes", <http://www.iana.org/assignments/
sdp-parameters/sdp-parameters.xml#sdp-parameters-15>. sdp-parameters/sdp-parameters.xml#sdp-parameters-15>.
[CCM] "S Description Protocol (SDP) RTCP-FB Codec Control [CCM] "S Description Protocol (SDP) RTCP-FB Codec Control
Messages", <http://www.iana.org/assignments/ Messages", <http://www.iana.org/assignments/
sdp-parameters/sdp-parameters.xml#sdp-parameters-19>. sdp-parameters/sdp-parameters.xml#sdp-parameters-19>.
skipping to change at page 51, line 7 skipping to change at page 55, line 37
Holmberg, C., Alvestrand, H., and C. Jennings, Holmberg, C., Alvestrand, H., and C. Jennings,
"Multiplexing Negotiation Using Session Description "Multiplexing Negotiation Using Session Description
Protocol (SDP) Port Numbers", Protocol (SDP) Port Numbers",
draft-ietf-mmusic-sdp-bundle-negotiation-03 (work in draft-ietf-mmusic-sdp-bundle-negotiation-03 (work in
progress), February 2013. progress), February 2013.
[IANA] "S Description Protocol (SDP) Parameters", <http:// [IANA] "S Description Protocol (SDP) Parameters", <http://
www.iana.org/assignments/sdp-parameters/ www.iana.org/assignments/sdp-parameters/
sdp-parameters.xml>. sdp-parameters.xml>.
[MEDIA_CAP]
Kaplan, H., Hedayat, K., and N. Venna, "S Description
Protocol (SDP) Media Capabilities Negotiation",
draft-ietf-mmusic-sdp-media-capabilities-17 (work in
progress), January 2013.
[MEDIA_LOOPBACK] [MEDIA_LOOPBACK]
Kaplan, H., Hedayat, K., Venna, N., Jones, P., and N. Kaplan, H., Hedayat, K., Venna, N., Jones, P., and N.
Stratton, "An Extension to the Session Description Stratton, "An Extension to the Session Description
Protocol (SDP) and Real-time Transport Protocol (RTP) for Protocol (SDP) and Real-time Transport Protocol (RTP) for
Media Loopback", Internet-Draft 6489, January 2013. Media Loopback", Internet-Draft 6489, January 2013.
[QOS] "S Description Protocol (SDP) QoS Mechanism Tokens", <http [QOS] "S Description Protocol (SDP) QoS Mechanism Tokens", <http
://www.iana.org/assignments/sdp-parameters/ ://www.iana.org/assignments/sdp-parameters/
sdp-parameters.xml#sdp-parameters-20>. sdp-parameters.xml#sdp-parameters-20>.
skipping to change at page 55, line 37 skipping to change at page 60, line 13
for RTP over UDP", RFC 6679, August 2012. for RTP over UDP", RFC 6679, August 2012.
[RFC6714] Holmberg, C., Blau, S., and E. Burger, "Connection [RFC6714] Holmberg, C., Blau, S., and E. Burger, "Connection
Establishment for Media Anchoring (CEMA) for the Message Establishment for Media Anchoring (CEMA) for the Message
Session Relay Protocol (MSRP)", RFC 6714, August 2012. Session Relay Protocol (MSRP)", RFC 6714, August 2012.
[RFC6773] Phelan, T., Fairhurst, G., and C. Perkins, "DCCP-UDP: A [RFC6773] Phelan, T., Fairhurst, G., and C. Perkins, "DCCP-UDP: A
Datagram Congestion Control Protocol UDP Encapsulation for Datagram Congestion Control Protocol UDP Encapsulation for
NAT Traversal", RFC 6773, November 2012. NAT Traversal", RFC 6773, November 2012.
[RFC6781] Gimlan, R., Evan, R., and F. Andreasen, "Session
Description Protocol (SDP) Media Capabilities
Negotiation", RFC 6781, Febrauary 2013.
[RFC6787] Burnett, D. and S. Shanmugham, "Media Resource Control [RFC6787] Burnett, D. and S. Shanmugham, "Media Resource Control
Protocol Version 2 (MRCPv2)", RFC 6787, November 2012. Protocol Version 2 (MRCPv2)", RFC 6787, November 2012.
[RTCP-FB] "S Description Protocol (SDP) RTCP Feedback attributes", < [RTCP-FB] "S Description Protocol (SDP) RTCP Feedback attributes", <
http://www.iana.org/assignments/sdp-parameters/ http://www.iana.org/assignments/sdp-parameters/
sdp-parameters.xml#sdp-parameters-14>. sdp-parameters.xml#sdp-parameters-14>.
[SSRC-GROUP] [SSRC-GROUP]
"S Description Protocol (SDP) "ssrc-group" semantics", <ht "S Description Protocol (SDP) "ssrc-group" semantics", <ht
tp://www.iana.org/assignments/sdp-parameters/ tp://www.iana.org/assignments/sdp-parameters/
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