Network Working Group                                            E. Ivov
Internet-Draft                                                     Jitsi
Intended status: Standards Track                                A. Roach
Expires: February 25, 2014                                       Mozilla
                                                         August 24, 2013


       A Session Initiation Protocol (SIP) usage for Trickle ICE
                     draft-ivov-dispatch-sdpfrag-01

Abstract

   This document registers the application/sdpfrag Multipurpose Internet
   Mail Extensions (MIME) media type.  This type is similar to
   application/sdp, but allows certain subsets of well formed session
   descriptions, as per the Session Description Protocol (SDP), to be
   represented instead of requiring a complete SDP session description.
   The "a=candidate" lines that are incrementally exchanged between
   Trickle ICE agents are one example usage of the application/sdpfrag.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on February 25, 2014.

Copyright Notice

   Copyright (c) 2013 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   (http://trustee.ietf.org/license-info) in effect on the date of
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   to this document.  Code Components extracted from this document must



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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.   Definition: application/sdpfrag  . . . . . . . . . . . . . .   2
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   5.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   3
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   3
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   3
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   3
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   3

1.  Introduction

   The application/sdp MIME media type defined in [RFC4566] carries an
   entire well formed SDP session description.  Yet, creating such a
   description may sometimes require a relatively long time as, for
   example, would be the case when the Interactive Connectivity
   Establishment (ICE) [RFC5245] protocol is in use and candidates need
   to be acquire in different, often time consuming methods.  Some
   applications may therefore choose to use mechanisms like Trickle ICE
   [I-D.ivov-mmusic-trickle-ice] that would allow them to send initial
   session descriptions with only readily available information and then
   exchange candidates only when they become available.

   This document does NOT provide a mechanism to segment an SDP session
   description into multiple pieces for separate transport and later
   reassemble.

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 [RFC2119].

3.  Definition: application/sdpfrag

   A valid application/sdpfrag part is one that could be obtained by
   starting with some valid SDP session description and deleting any
   number of lines.

   [TODO maybe mention that we can only do frags with the declarative
   parts of an SDP offer/answer and not with the ones used in
   negotiations.]



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   [TODO maybe explain how attributes can be linked to an m line or at
   least say that this will be defined by usages.]

4.  Security Considerations

   [TODO]

5.  Acknowledgements

   [TODO]

6.  References

6.1.  Normative References

   [I-D.ivov-mmusic-trickle-ice]
              Ivov, E., Rescorla, E., and J. Uberti, "Trickle ICE:
              Incremental Provisioning of Candidates for the Interactive
              Connectivity Establishment (ICE) Protocol", draft-ivov-
              mmusic-trickle-ice-01 (work in progress), March 2013.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3264]  Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model
              with Session Description Protocol (SDP)", RFC 3264, June
              2002.

   [RFC4566]  Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
              Description Protocol", RFC 4566, July 2006.

   [RFC5245]  Rosenberg, J., "Interactive Connectivity Establishment
              (ICE): A Protocol for Network Address Translator (NAT)
              Traversal for Offer/Answer Protocols", RFC 5245, April
              2010.

6.2.  Informative References

   [RFC1918]  Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and
              E. Lear, "Address Allocation for Private Internets", BCP
              5, RFC 1918, February 1996.

Authors' Addresses








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   Emil Ivov
   Jitsi
   Strasbourg  67000
   France

   Phone: +33 6 72 81 15 55
   Email: emcho@jitsi.org


   Adam Roach
   Mozilla
   Dallas, TX
   US

   Email: adam@nostrum.com




































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