RFC 3407 (rfc3407) - Page 1 of 10

Session Description Protocol (SDP) Simple Capability Declaration

Alternative Format: Original Text Document
Next >
Network Working Group                                       F. Andreasen
Request for Comments: 3407                                 Cisco Systems
Category: Standards Track                                   October 2002


   Session Description Protocol (SDP) Simple Capability Declaration

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 defines a set of Session Description Protocol (SDP)
   attributes that enables SDP to provide a minimal and backwards
   compatible capability declaration mechanism.  Such capability
   declarations can be used as input to a subsequent session
   negotiation, which is done by means outside the scope of this
   document.  This provides a simple and limited solution to the general
   capability negotiation problem being addressed by the next generation
   of SDP, also known as SDPng.

1. Conventions Used in this Document

   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 [2].

2. Introduction

   The Session Description Protocol (SDP) [3] describes multimedia
   sessions for the purposes of session announcement, session
   invitation, and other forms of multimedia session initiation.  SDP
   was not intended to provide capability negotiation.  However, as the
   need for this has become increasingly important, work has begun on a
   "next generation SDP" (SDPng) [4,5] that supports both session
   description and capability negotiation.  SDPng is not anticipated to
   be backwards compatible with SDP and work on SDPng is currently in
   the early stages.  However, several other protocols, e.g. SIP [6] and
   Media Gateway Control Protocol (MGCP) [7], use SDP and are likely to



Andreasen                   Standards Track
Next >