Sending Multiple RTP Streams in a Single RTP Session
draft-ietf-avtcore-rtp-multi-stream-11

The information below is for an old version of the document that is already published as an RFC
Document Type RFC Internet-Draft (avtcore WG)
Authors Jonathan Lennox  , Magnus Westerlund  , Qin Wu  , Colin Perkins 
Last updated 2017-03-07 (latest revision 2015-12-11)
Replaces draft-lennox-avtcore-rtp-multi-stream
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Details
AVTCORE                                                        J. Lennox
Internet-Draft                                                     Vidyo
Updates: 3550, 4585 (if approved)                          M. Westerlund
Intended status: Standards Track                                Ericsson
Expires: June 13, 2016                                             Q. Wu
                                                                  Huawei
                                                              C. Perkins
                                                   University of Glasgow
                                                       December 11, 2015

          Sending Multiple RTP Streams in a Single RTP Session
                 draft-ietf-avtcore-rtp-multi-stream-11

Abstract

   This memo expands and clarifies the behaviour of Real-time Transport
   Protocol (RTP) endpoints that use multiple synchronization sources
   (SSRCs).  This occurs, for example, when an endpoint sends multiple
   RTP streams in a single RTP session.  This memo updates RFC 3550 with
   regards to handling multiple SSRCs per endpoint in RTP sessions, with
   a particular focus on RTCP behaviour.  It also updates RFC 4585 to
   update and clarify the calculation of the timeout of SSRCs and the
   inclusion of feedback messages.

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
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   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 June 13, 2016.

Copyright Notice

   Copyright (c) 2015 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

Lennox, et al.            Expires June 13, 2016                 [Page 1]
Internet-Draft  Multiple Media Streams in an RTP Session   December 2015

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Use Cases For Multi-Stream Endpoints  . . . . . . . . . . . .   3
     3.1.  Endpoints with Multiple Capture Devices . . . . . . . . .   3
     3.2.  Multiple Media Types in a Single RTP Session  . . . . . .   4
     3.3.  Multiple Stream Mixers  . . . . . . . . . . . . . . . . .   4
     3.4.  Multiple SSRCs for a Single Media Source  . . . . . . . .   4
   4.  Use of RTP by endpoints that send multiple media streams  . .   5
   5.  Use of RTCP by Endpoints that send multiple media streams . .   5
     5.1.  RTCP Reporting Requirement  . . . . . . . . . . . . . . .   5
     5.2.  Initial Reporting Interval  . . . . . . . . . . . . . . .   6
     5.3.  Aggregation of Reports into Compound RTCP Packets . . . .   7
       5.3.1.  Maintaining AVG_RTCP_SIZE . . . . . . . . . . . . . .   7
       5.3.2.  Scheduling RTCP when Aggregating Multiple SSRCs . . .   9
     5.4.  Use of RTP/AVPF or RTP/SAVPF Feedback . . . . . . . . . .  11
       5.4.1.  Choice of SSRC for Feedback Packets . . . . . . . . .  11
       5.4.2.  Scheduling an RTCP Feedback Packet  . . . . . . . . .  12
   6.  Adding and Removing SSRCs . . . . . . . . . . . . . . . . . .  14
     6.1.  Adding RTP Streams  . . . . . . . . . . . . . . . . . . .  14
     6.2.  Removing RTP Streams  . . . . . . . . . . . . . . . . . .  15
   7.  RTCP Considerations for Streams with Disparate Rates  . . . .  16
     7.1.  Timing out SSRCs  . . . . . . . . . . . . . . . . . . . .  17
       7.1.1.  Problems with the RTP/AVPF T_rr_interval Parameter  .  18
       7.1.2.  Avoiding Premature Timeout  . . . . . . . . . . . . .  19
       7.1.3.  Interoperability Between RTP/AVP and RTP/AVPF . . . .  19
       7.1.4.  Updated SSRC Timeout Rules  . . . . . . . . . . . . .  20
     7.2.  Tuning RTCP transmissions . . . . . . . . . . . . . . . .  20
       7.2.1.  RTP/AVP and RTP/SAVP  . . . . . . . . . . . . . . . .  21
       7.2.2.  RTP/AVPF and RTP/SAVPF  . . . . . . . . . . . . . . .  22
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