Network Working Group E. Ivov Internet-Draft Jitsi Intended status: Standards Track A. Roach Expires: August 23, 2013 Mozilla February 19, 2013 A Session Initiation Protocol (SIP) usage for Trickle ICE draft-ivov-dispatch-sdpfrag-00 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 Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on August 23, 2013. 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 Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must Ivov & Roach Expires August 23, 2013 [Page 1] Internet-Draft Trickle ICE for SIP February 2013 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 . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Definition: application/sdpfrag . . . . . . . . . . . . . . . . 3 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 3 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 3 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 4 6.1. Normative References . . . . . . . . . . . . . . . . . . . 4 6.2. Informative References . . . . . . . . . . . . . . . . . . 4 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 4 Ivov & Roach Expires August 23, 2013 [Page 2] Internet-Draft Trickle ICE for SIP February 2013 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.] [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] Ivov & Roach Expires August 23, 2013 [Page 3] Internet-Draft Trickle ICE for SIP February 2013 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-00 (work in progress), January 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 Emil Ivov Jitsi Strasbourg 67000 France Phone: +33 6 72 81 15 55 Email: emcho@jitsi.org Ivov & Roach Expires August 23, 2013 [Page 4] Internet-Draft Trickle ICE for SIP February 2013 Adam Roach Mozilla Dallas, TX US Email: adam@nostrum.com Ivov & Roach Expires August 23, 2013 [Page 5]