Support for IPv6 in Session Description Protocol (SDP)

Network Working Group                                           S. Olson
Request for Comments: 3266                                     Microsoft
Updates: 2327                                               G. Camarillo
Category: Standards Track                                       Ericsson
                                                             A. B. Roach
                                                             dynamicsoft
                                                               June 2002


         Support for IPv6 in Session Description Protocol (SDP)

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   This document describes the use of Internet Protocol Version 6 (IPv6)
   addresses in conjunction with the Session Description Protocol (SDP).
   Specifically, this document clarifies existing text in SDP with
   regards to the syntax of IPv6 addresses.

1. Introduction

   SDP is intended for describing multimedia sessions for the purposes
   of session announcement, session invitation, and other forms of
   multimedia session initiation.  It is a text format description that
   provides many details of a multimedia session including: the
   originator of the session, a URL related to the session, the
   connection address for the session media(s), and optional attributes
   for the session media(s).  Each of these pieces of information may
   involve one or more IPv6 addresses.  The ABNF for IP addresses in SDP
   currently leaves the syntax for IPv6 addresses undefined.  This
   document attempts to complete the ABNF to include IPv6 addresses.

   Accordingly, the address type "IP6" indicating an IPv6 address,
   should be allowed in the connection field, "c=", of the SDP.  The
   ABNF already reflects this, though the "Connection Data" text under
   section 6 of RFC 2328 currently only defines the "IP4" address type.

2. Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [5].

3. Syntax

   RFC 2373 [1] gives an ABNF for the text representation of IPv6
   addresses in Appendix B.  RFC 2732 [3] covers the text representation
   of IPv6 addresses when used within a URL.  Using the ABNF described
   in these documents, the following updated ABNF for SDP is proposed.

      uri =                 ; defined in RFC1630 and RFC2732

      multicast-address =   IP4-multicast / IP6-multicast

      IP4-multicast =       m1 3*( "." decimal-uchar )
                            "/" ttl [ "/" integer ]
                            ; IPv4 multicast addresses may be in the
                            ; range 224.0.0.0 to 239.255.255.255

      m1 =                  ("22" ("4"/"5"/"6"/"7"/"8"/"9")) /
                            ("23" DIGIT ))

      IP6-multicast =       hexpart
                            ; IPv6 address starting with FF

      addr =                FQDN / unicast-address

      FQDN =                4*(alpha-numeric/"-"/".")
                            ; fully qualified domain name as specified
                            ; in RFC1035
      unicast-address =     IP4-address / IP6-address

      IP4-address =         b1 3*("." decimal-uchar) / "0.0.0.0"

      b1 =                  decimal-uchar
                            ; less than "224"; not "0" or "127"

      ; The following is from RFC2373 Appendix B. It is a direct copy.
      IP6-address =         hexpart [ ":" IP4-address ]

      hexpart =             hexseq / hexseq "::" [ hexseq ] /
                            "::" [ hexseq ]

      hexseq  =             hex4 *( ":" hex4)

      hex4    =             1*4HEXDIG

4. Example SDP description with IPv6 addresses

   The following is an example SDP description using the above ABNF for
   IPv6 addresses.  In particular, the origin and connection fields
   contain IPv6 addresses.

      v=0
      o=nasa1 971731711378798081 0 IN IP6 2201:056D::112E:144A:1E24
      s=(Almost) live video feed from Mars-II satellite
      p=+1 713 555 1234
      c=IN IP6 FF1E:03AD::7F2E:172A:1E24
      t=3338481189 3370017201
      m=audio 6000 RTP/AVP 2
      a=rtpmap:2 G726-32/8000
      m=video 6024 RTP/AVP 107
      a=rtpmap:107 H263-1998/90000

5. Note for implementors

   An implementation may receive an SDP session description with an IPv6
   address whose format [1] is internally that of an IPv4 mapped
   address.  Note that such an address is actually the address of an
   IPv4-only node, and implementors are warned to interpret IPv4 mapped
   addresses as equivalent to IP4.

6. IANA Considerations

   This document updates the definition of the IP6 addrtype parameter
   found in RFC 2327.

7. Security Considerations

   No additional considerations above what is stated in section 7 of RFC
   2327.

8. References

   [1]   Hinden, R. and S. Deering, "IP Version 6 Addressing
         Architecture", RFC 2373, July 1998.

   [2]   Handley, M. and V. Jacobson, "SDP: Session Description
         Protocol", RFC 2327, April 1998.

   [3]   Hinden, R., Carpenter, B. and L. Masinter, "Format for Literal
         IPv6 Addresses in URL's", RFC 2732, December 1999.

   [4]   Crocker, D. and P. Overell, "Augmented BNF for Syntax
         Specifications: ABNF", RFC 2234, November 1997.

   [5]   Bradner, S., "Key words for Use in RFCs to Indicate Requirement
         Levels", BCP 14, RFC 2119, March 1997.

9. Authors' Addresses

   Sean Olson
   Microsoft
   One Microsoft Way
   Redmond, WA 98052
   USA

   EMail: seanol@microsoft.com


   Gonzalo Camarillo
   Ericsson
   Advanced Signalling Research Lab.
   FIN-02420 Jorvas
   Finland

   Phone: +358 9 299 3371
   Fax: +358 9 299 3118
   EMail: Gonzalo.Camarillo@ericsson.com


   Adam Roach
   dynamicsoft
   5100 Tennyson Parkway
   Suite 1200
   Plano, TX 75024
   USA

   EMail: adam@dynamicsoft.com
   Voice: <sip:adam@dynamicsoft.com>

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Acknowledgement

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