SDP Capability Negotiation

Document Type Replaced Internet-Draft (individual)
Author Flemming Andreasen 
Last updated 2008-04-16 (latest revision 2006-10-22)
Replaced by RFC 5939
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Expired & archived
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IESG IESG state Replaced by draft-ietf-mmusic-sdp-capability-negotiation
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


The Session Description Protocol (SDP) was intended for describing multimedia sessions for the purposes of session announcement, session invitation, and other forms of multimedia session initiation. SDP was not intended to provide capability indication or capability negotiation, however over the years, SDP has seen widespread adoption and as a result it has been gradually extended to provide limited support for these. SDP and its current extensions however do not have the ability to negotiate one or more alternative transport protocols (e.g. RTP profiles) which makes it particularly difficult to deploy new RTP profiles such as secure RTP and RTP with RTCP-based feedback. The purpose of this document is to address that by identifying a set of requirements, evaluate existing work in this area, and provide a recommended solution for extending SDP with capability negotiation.


Flemming Andreasen (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)