Negotiating Media Multiplexing Using the Session Description Protocol (SDP)

Document Type Active Internet-Draft (individual)
Authors Christer Holmberg  , Harald Alvestrand  , Cullen Jennings 
Last updated 2021-03-31
Stream (None)
Intended RFC status (None)
Formats plain text html xml pdf htmlized (tools) htmlized bibtex
Stream Stream state (No stream defined)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date
Responsible AD (None)
Send notices to (None)

MMUSIC Working Group                                         C. Holmberg
Internet-Draft                                                  Ericsson
Obsoletes: 8843 (if approved)                              H. Alvestrand
Updates: 3264, 5888, 7941 (if approved)                           Google
Intended status: Standards Track                             C. Jennings
Expires: 2 October 2021                                            Cisco
                                                           31 March 2021

 Negotiating Media Multiplexing Using the Session Description Protocol


   This specification defines a new Session Description Protocol (SDP)
   Grouping Framework extension called 'BUNDLE'.  The extension can be
   used with the SDP offer/answer mechanism to negotiate the usage of a
   single transport (5-tuple) for sending and receiving media described
   by multiple SDP media descriptions ("m=" sections).  Such transport
   is referred to as a BUNDLE transport, and the media is referred to as
   bundled media.  The "m=" sections that use the BUNDLE transport form
   a BUNDLE group.

   This specification defines a new RTP Control Protocol (RTCP) Source
   Description (SDES) item and a new RTP header extension.

   This specification updates RFCs 3264, 5888, and 7941.

   This specification obsoletes RFC 8843.

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

   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 2 October 2021.

Copyright Notice

   Copyright (c) 2021 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 (
   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 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.

   This document may contain material from IETF Documents or IETF
   Contributions published or made publicly available before November
   10, 2008.  The person(s) controlling the copyright in some of this
   material may not have granted the IETF Trust the right to allow
   modifications of such material outside the IETF Standards Process.
   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.

Table of Contents

   1.  Introduction
     1.1.  Background
     1.2.  BUNDLE Mechanism
     1.3.  Protocol Extensions
     1.4.  Changes from RFC 8843
   2.  Terminology
   3.  Conventions
   4.  Applicability Statement
   5.  SDP Grouping Framework BUNDLE Extension
   6.  SDP 'bundle-only' Attribute
   7.  SDP Offer/Answer Procedures
     7.1.  Generic SDP Considerations
       7.1.1.  Connection Data ("c=")
       7.1.2.  Bandwidth ("b=")
       7.1.3.  Attributes ("a=")
     7.2.  Generating the Initial SDP Offer
       7.2.1.  Suggesting the Offerer-Tagged 'm=' Section
       7.2.2.  Example: Initial SDP Offer
     7.3.  Generating the SDP Answer
       7.3.1.  Answerer Selection of Tagged 'm=' Sections
       7.3.2.  Moving a Media Description Out of a BUNDLE Group
       7.3.3.  Rejecting a Media Description in a BUNDLE Group
       7.3.4.  Example: SDP Answer
     7.4.  Offerer Processing of the SDP Answer
     7.5.  Modifying the Session
       7.5.1.  Adding a Media Description to a BUNDLE Group
       7.5.2.  Moving a Media Description Out of a BUNDLE Group
       7.5.3.  Disabling a Media Description in a BUNDLE Group
   8.  Protocol Identification
     8.1.  STUN, DTLS, and SRTP
   9.  RTP Considerations
     9.1.  Single RTP Session
       9.1.1.  Payload Type (PT) Value Reuse
     9.2.  Associating RTP/RTCP Streams with the Correct SDP Media
     9.3.  RTP/RTCP Multiplexing
Show full document text