draft-ietf-ecrit-dhc-lost-discovery-02.txt   draft-ietf-ecrit-dhc-lost-discovery-03.txt 
ECRIT H. Schulzrinne ECRIT H. Schulzrinne
Internet-Draft Columbia University Internet-Draft Columbia University
Intended status: Standards Track J. Polk Intended status: Standards Track J. Polk
Expires: January 9, 2008 Cisco Expires: November 30, 2008 Cisco
H. Tschofenig H. Tschofenig
Nokia Siemens Networks Nokia Siemens Networks
July 8, 2007 May 29, 2008
A Dynamic Host Configuration Protocol (DHCP) based Location-to-Service A Dynamic Host Configuration Protocol (DHCP) based Location-to-Service
Translation Protocol (LoST) Discovery Procedure Translation Protocol (LoST) Discovery Procedure
draft-ietf-ecrit-dhc-lost-discovery-02.txt draft-ietf-ecrit-dhc-lost-discovery-03.txt
Status of this Memo Status of this Memo
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Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract Abstract
The Location-to-Service Translation Protocol (LoST) describes an XML- The Location-to-Service Translation Protocol (LoST) describes an XML-
based protocol for mapping service identifiers and geospatial or based protocol for mapping service identifiers and geospatial or
civic location information to service contact Uniform Resource civic location information to service contact Uniform Resource
Locators (URLs). LoST servers can be located anywhere but a Locators (URLs). LoST servers can be located anywhere but a
placement closer to the end host, e.g., in the access network, is placement closer to the end host, e.g., in the access network, is
desireable. Such a LoST server placement provides benefits in desireable. Such a LoST server placement provides benefits in
disaster situations with intermittent network connectivity regarding disaster situations with intermittent network connectivity regarding
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This document describes how a LoST client can discover a LoST server This document describes how a LoST client can discover a LoST server
using the Dynamic Host Configuration Protocol (DHCP). using the Dynamic Host Configuration Protocol (DHCP).
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Domain Name Encoding . . . . . . . . . . . . . . . . . . . . . 3 3. Domain Name Encoding . . . . . . . . . . . . . . . . . . . . . 3
4. LoST Server DHCPv4 Option . . . . . . . . . . . . . . . . . . . 4 4. LoST Server DHCPv4 Option . . . . . . . . . . . . . . . . . . . 4
5. LoST Server DHCPv6 Option . . . . . . . . . . . . . . . . . . . 4 5. LoST Server DHCPv6 Option . . . . . . . . . . . . . . . . . . . 5
6. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 6. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
7.1. IANA Consideration for DHCPv4 Option . . . . . . . . . . . 6 7.1. IANA Consideration for DHCPv4 Option . . . . . . . . . . . 6
7.2. IANA Consideration for DHCPv6 Option . . . . . . . . . . . 6 7.2. IANA Consideration for DHCPv6 Option . . . . . . . . . . . 6
8. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 8. Security Considerations . . . . . . . . . . . . . . . . . . . . 6
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
10.1. Normative References . . . . . . . . . . . . . . . . . . . 7 10.1. Normative References . . . . . . . . . . . . . . . . . . . 7
10.2. Informative References . . . . . . . . . . . . . . . . . . 7 10.2. Informative References . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8
Intellectual Property and Copyright Statements . . . . . . . . . . 9 Intellectual Property and Copyright Statements . . . . . . . . . . 9
1. Introduction 1. Introduction
The Location-to-Service Translation Protocol (LoST) The Location-to-Service Translation Protocol (LoST)
[I-D.ietf-ecrit-lost] describes an XML-based protocol for mapping [I-D.ietf-ecrit-lost] describes an XML-based protocol for mapping
service identifiers and geospatial or civic location information to service identifiers and geospatial or civic location information to
service contact Uniform Resource Locators (URLs). service contact Uniform Resource Locators (URLs).
In order to interact with a LoST server, the LoST client finally In order to interact with a LoST server, the LoST client eventually
needs to know its IP address. Several mechanisms can be used to needs to discover the server's IP address. Several mechanisms can be
learn this address, including manual configuration. In environments used to learn this address, including manual configuration. In
where the access network itself either deploys a LoST server or knows environments where the access network itself either deploys a LoST
a third party that operates a LoST server DHCP can provide the end server or knows a third party that operates a LoST server, DHCP can
host with a domain name. This domain name is then used as input to provide the end host with a domain name. This domain name is then
the DNS-based resolution mechanism described in LoST used as input to the DNS-based resolution mechanism described in LoST
[I-D.ietf-ecrit-lost] that reuses the URI-enabled NAPTR specification [I-D.ietf-ecrit-lost] that reuses the URI-enabled NAPTR specification
(see [RFC4848]). (see [RFC4848]).
This document specifies a DHCPv4 and a DHCPv6 option that allows LoST This document specifies a DHCPv4 and a DHCPv6 option that allows LoST
clients to discover local LoST servers. clients to discover local LoST servers.
Section 2 provides terminology. Section 4 describes the DHCPv4 Section 2 provides terminology. Section 3 shows the encoding of the
option while Section 5 describes the DHCPv6 option, with the same domain name. Section 4 describes the DHCPv4 option while Section 5
functionality. IANA and Security Considerations complete the describes the DHCPv6 option, with the same functionality. IANA and
document in Section 7 and Section 8. Security Considerations complete the document in Section 7 and
Section 8.
2. Terminology 2. Terminology
In this document, the key words "MUST", "MUST NOT", "REQUIRED", In this document, the key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
and "OPTIONAL" are to be interpreted as described in RFC 2119 and "OPTIONAL" are to be interpreted as described in RFC 2119
[RFC2119]. [RFC2119].
Within this document, we use terminology from Within this document, we use terminology from [RFC5012] and
[I-D.ietf-ecrit-requirements] and [I-D.ietf-ecrit-lost]. [I-D.ietf-ecrit-lost].
3. Domain Name Encoding 3. Domain Name Encoding
This section describes the encoding of the domain name used in the This section describes the encoding of the domain name used in the
DHCPv4 option shown in Section 4 and also used in the DHCPv6 option DHCPv4 option shown in Section 4 and also used in the DHCPv6 option
shown in Section 5. shown in Section 5.
The domain name is encoded according to Section 3.1 of RFC 1035 The domain name is encoded according to Section 3.1 of RFC 1035
[RFC1035] whereby each label is represented as a one octet length [RFC1035] whereby each label is represented as a one octet length
field followed by that number of octets. The domain name ends with field followed by that number of octets. Since every domain name
the null label of the root, a domain name is terminated by a length ends with the null label of the root, a domain name is terminated by
byte of zero. The high order two bits of every length octet MUST be a length byte of zero. The high order two bits of every length octet
zero, and the remaining six bits of the length field limit the label MUST be zero, and the remaining six bits of the length field limit
to 63 octets or less. To simplify implementations, the total length the label to 63 octets or less. To simplify implementations, the
of a domain name (i.e., label octets and label length octets) is total length of a domain name (i.e., label octets and label length
restricted to 255 octets or less. octets) is restricted to 255 octets or less.
For DHCPv4 only: If the length of the domain name exceeds the
maximum permissible within a single option (i.e., 254 octets), then
the domain name MUST be represented in the DHCP message as specified
in [RFC3396].
4. LoST Server DHCPv4 Option 4. LoST Server DHCPv4 Option
The LoST server DHCPv4 option carries a DNS (RFC 1035 [RFC1035]) The LoST server DHCPv4 option carries a DNS (RFC 1035 [RFC1035])
fully-qualified domain name to be used by the LoST client to locate a fully-qualified domain name to be used by the LoST client to locate a
LoST server. LoST server.
The DHCP option for this encoding has the following format: The DHCP option for this encoding has the following format:
Code Len LoST Server Domain Name Code Len LoST Server Domain Name
+-----+-----+-----+-----+-----+-----+-----+---- +-----+-----+-----+-----+-----+-----+-----+----
| TBD | n | s1 | s2 | s3 | s4 | s5 | ... | TBD1| n | s1 | s2 | s3 | s4 | s5 | ...
+-----+-----+-----+-----+-----+-----+-----+---- +-----+-----+-----+-----+-----+-----+-----+----
Figure 1: LoST FQDN DHCPv4 Option Figure 1: LoST FQDN DHCPv4 Option
The values s1, s2, s3, etc. represent the domain name labels in the
domain name encoding. Note that the length field in the DHCPv4
option represents the length of the entire domain name encoding,
whereas the length fields in the domain name encoding (see Section 3)
is the length of a single domain name label.
Code: OPTION_V4_LOST (TBD1) Code: OPTION_V4_LOST (TBD1)
Len: Length of the 'LoST Server Domain Name' field Len: Length of the 'LoST Server Domain Name' field
in octets; variable. in octets; variable.
LoST server Domain Name: The domain name of the LoST LoST server Domain Name: The domain name of the LoST
server for the client to use. server for the client to use.
A DHCPv4 client MAY request a LoST server domain name in an Parameter
Request List option, as described in [RFC2131].
The encoding of the domain name is described in Section 3. The encoding of the domain name is described in Section 3.
Only a single domain name MUST be present in the DHCPv4 option. This option contains a single doamin name, and as such MUST contain
precisely one root label.
5. LoST Server DHCPv6 Option 5. LoST Server DHCPv6 Option
This document defines a DHCPv6 options to carry a domain name. This section defines a DHCPv6 option to carry a domain name.
The DHCPv6 option has the format shown in Figure 3. The DHCPv6 option has the format shown in Figure 2.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_V6_LOST | option-length | | OPTION_V6_LOST | option-length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LoST Server Domain Name | | LoST Server Domain Name |
| ... | | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: DHCPv6 Option for LoST Server Domain Name List Figure 2: DHCPv6 Option for LoST Server Domain Name List
option-code: OPTION_V6_LOST (TBD2) option-code: OPTION_V6_LOST (TBD2)
option-length: Length of the 'LoST Server Domain Name' field option-length: Length of the 'LoST Server Domain Name' field
in octets; variable. in octets; variable.
LoST server Domain Name: The domain name of the LoST LoST server Domain Name: The domain name of the LoST
server for the client to use. server for the client to use.
A DHCPv6 client MAY request a LoST server domain name in an Options A DHCPv6 client MAY request a LoST server domain name in an Options
Request Option (ORO), as described in [RFC3315]. Request Option (ORO), as described in [RFC3315].
A DHCPv4 client MAY request a LoST server domain name in an Parameter
Request List option, as described in [RFC2131].
The encoding of the domain name is described in Section 3. The encoding of the domain name is described in Section 3.
Only a single domain name MUST be present in the DHCPv6 option. This option contains a single doamin name, and as such MUST contain
precisely one root label.
6. Example 6. Example
This section shows an example of a DHCPv4 option where the DHCP This section shows an example of a DHCPv4 option where the DHCP
server wants to offer the "example.com" domain name to the client as server wants to offer the "example.com" domain name to the client as
input to the U-NAPTR LoST discovery procedure. This domain name input to the U-NAPTR LoST discovery procedure. This domain name
would be encoded as follows: would be encoded as follows:
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|TBD|13 | 7 |'e'|'x'|'a'|'m'|'p'|'l'|'e'| 3 |'c'|'o'|'m'| 0 | |TBD1|13 | 7 |'e'|'x'|'a'|'m'|'p'|'l'|'e'| 3 |'c'|'o'|'m'| 0 |
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
Figure 5: Example for a LoST FQDN DHCPv4 Option Figure 3: Example for a LoST FQDN DHCPv4 Option
7. IANA Considerations 7. IANA Considerations
7.1. IANA Consideration for DHCPv4 Option 7.1. IANA Consideration for DHCPv4 Option
The following DHCPv4 option code for the Location-to-Service The following DHCPv4 option code for the Location-to-Service
Translation Protocol (LoST) server option must be assigned by IANA: Translation Protocol (LoST) server option must be assigned by IANA:
Option Name Value Described in Option Name Value Described in
----------------------------------------------- -----------------------------------------------
OPTION_V4_LOST TBD Section 4 OPTION_V4_LOST TBD1 Section 4
7.2. IANA Consideration for DHCPv6 Option 7.2. IANA Consideration for DHCPv6 Option
IANA is requested to assign the following DHCPv6 option codes for the IANA is requested to assign the following DHCPv6 option codes for the
Location-to-Service Translation Protocol (LoST) options: Location-to-Service Translation Protocol (LoST) options:
Option Name Value Described in Option Name Value Described in
------------------------------------------------ ------------------------------------------------
OPTION_V6_LOST TBD Section 5 OPTION_V6_LOST TBD2 Section 5
8. Security Considerations 8. Security Considerations
If an adversary manages to modify the response from a DHCP server or If an adversary manages to modify the response from a DHCP server or
insert its own response, a LoST client could be led to contact a insert its own response, a LoST client could be led to contact a
rogue LoST server under the control of the adversary or be given an rogue LoST server under the control of the adversary or be given an
invalid address. These threats are documented in invalid address. These threats are documented in [RFC5069]. The
[I-D.ietf-ecrit-security-threats]. The security considerations in security considerations in [RFC2131], [RFC2132] and [RFC3315] are
[RFC2131], [RFC2132] and [RFC3315] are applicable to this document. applicable to this document.
With respect to the LoST security mechanisms please refer to
[I-D.ietf-ecrit-lost].
9. Acknowledgements 9. Acknowledgements
The authors would like to thank Andrew Newton and Leslie Daigle for The authors would like to thank Andrew Newton and Leslie Daigle for
their draft review. We would like to particularly thank Andrew their draft review and Andy for the proposed simplifications.
Newton for the simplifications he proposed.
Mark Stapp did the document review of this document for the DHC Mark Stapp and David W. Hankins did the document review for the DHC
working group as part of the joint working group last call. working group as part of the joint working group last call.
We would like to thank Vijay K. Gurbani for the Gen-ART review.
Furthermore, we would like to thank Russ Housley, Tim Polk, Jari
Arkko, and Christian Vogt.
10. References 10. References
10.1. Normative References 10.1. Normative References
[RFC1034] Mockapetris, P., "Domain names - concepts and facilities", [RFC1034] Mockapetris, P., "Domain names - concepts and facilities",
STD 13, RFC 1034, November 1987. STD 13, RFC 1034, November 1987.
[RFC1035] Mockapetris, P., "Domain names - implementation and [RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987. specification", STD 13, RFC 1035, November 1987.
skipping to change at page 7, line 33 skipping to change at page 7, line 35
and M. Carney, "Dynamic Host Configuration Protocol for and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003. IPv6 (DHCPv6)", RFC 3315, July 2003.
[RFC3396] Lemon, T. and S. Cheshire, "Encoding Long Options in the [RFC3396] Lemon, T. and S. Cheshire, "Encoding Long Options in the
Dynamic Host Configuration Protocol (DHCPv4)", RFC 3396, Dynamic Host Configuration Protocol (DHCPv4)", RFC 3396,
November 2002. November 2002.
10.2. Informative References 10.2. Informative References
[I-D.ietf-ecrit-lost] [I-D.ietf-ecrit-lost]
Hardie, T., "LoST: A Location-to-Service Translation Hardie, T., Newton, A., Schulzrinne, H., and H.
Protocol", draft-ietf-ecrit-lost-05 (work in progress), Tschofenig, "LoST: A Location-to-Service Translation
March 2007. Protocol", draft-ietf-ecrit-lost-10 (work in progress),
May 2008.
[I-D.ietf-ecrit-requirements]
Schulzrinne, H. and R. Marshall, "Requirements for
Emergency Context Resolution with Internet Technologies",
draft-ietf-ecrit-requirements-13 (work in progress),
March 2007.
[I-D.ietf-ecrit-security-threats]
Taylor, T., "Security Threats and Requirements for
Emergency Call Marking and Mapping",
draft-ietf-ecrit-security-threats-04 (work in progress),
April 2007.
[RFC4848] Daigle, L., "Domain-Based Application Service Location [RFC4848] Daigle, L., "Domain-Based Application Service Location
Using URIs and the Dynamic Delegation Discovery Service Using URIs and the Dynamic Delegation Discovery Service
(DDDS)", RFC 4848, April 2007. (DDDS)", RFC 4848, April 2007.
[RFC5012] Schulzrinne, H. and R. Marshall, "Requirements for
Emergency Context Resolution with Internet Technologies",
RFC 5012, January 2008.
[RFC5069] Taylor, T., Tschofenig, H., Schulzrinne, H., and M.
Shanmugam, "Security Threats and Requirements for
Emergency Call Marking and Mapping", RFC 5069,
January 2008.
Authors' Addresses Authors' Addresses
Henning Schulzrinne Henning Schulzrinne
Columbia University Columbia University
Department of Computer Science Department of Computer Science
450 Computer Science Building 450 Computer Science Building
New York, NY 10027 New York, NY 10027
US US
Phone: +1 212 939 7004 Phone: +1 212 939 7004
skipping to change at page 8, line 28 skipping to change at page 8, line 28
James Polk James Polk
Cisco Cisco
2200 East President George Bush Turnpike 2200 East President George Bush Turnpike
Richardson, Texas 75082 Richardson, Texas 75082
US US
Email: jmpolk@cisco.com Email: jmpolk@cisco.com
Hannes Tschofenig Hannes Tschofenig
Nokia Siemens Networks Nokia Siemens Networks
Otto-Hahn-Ring 6 Linnoitustie 6
Munich, Bavaria 81739 Espoo 02600
Germany Finland
Phone: +49 89 636 40390 Phone: +358 (50) 4871445
Email: Hannes.Tschofenig@nsn.com Email: Hannes.Tschofenig@nsn.com
URI: http://www.tschofenig.com URI: http://www.tschofenig.priv.at
Full Copyright Statement Full Copyright Statement
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors contained in BCP 78, and except as set forth therein, the authors
retain all their rights. retain all their rights.
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
skipping to change at page 9, line 44 skipping to change at line 369
attempt made to obtain a general license or permission for the use of attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this such proprietary rights by implementers or users of this
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http://www.ietf.org/ipr. http://www.ietf.org/ipr.
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Acknowledgment
Funding for the RFC Editor function is provided by the IETF
Administrative Support Activity (IASA).
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