Sending Multiple RTP Streams in a Single RTP Session
RFC 8108
|
| Document |
Type |
|
RFC - Proposed Standard
(March 2017; No errata)
|
|
Last updated |
|
2017-03-07
|
|
Replaces |
|
draft-lennox-avtcore-rtp-multi-stream
|
|
Stream |
|
IETF
|
|
Formats |
|
plain text
pdf
html
bibtex
|
| Stream |
WG state
|
|
Submitted to IESG for Publication
|
|
Document shepherd |
|
Roni Even
|
|
Shepherd write-up |
|
Show
(last changed 2015-10-08)
|
| IESG |
IESG state |
|
RFC 8108 (Proposed Standard)
|
|
Consensus Boilerplate |
|
Yes
|
|
Telechat date |
|
|
|
Responsible AD |
|
Ben Campbell
|
|
Send notices to |
|
(None)
|
| IANA |
IANA review state |
|
Version Changed - Review Needed
|
|
IANA action state |
|
No IANA Actions
|
Internet Engineering Task Force (IETF) J. Lennox
Request for Comments: 8108 Vidyo
Updates: 3550, 4585 M. Westerlund
Category: Standards Track Ericsson
ISSN: 2070-1721 Q. Wu
Huawei
C. Perkins
University of Glasgow
March 2017
Sending Multiple RTP Streams in a Single RTP Session
Abstract
This memo expands and clarifies the behavior 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
regard to handling multiple SSRCs per endpoint in RTP sessions, with
a particular focus on RTP Control Protocol (RTCP) behavior. It also
updates RFC 4585 to change and clarify the calculation of the timeout
of SSRCs and the inclusion of feedback messages.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc8108.
Lennox, et al. Standards Track [Page 1]
RFC 8108 Multiple Media Streams in an RTP Session March 2017
Copyright Notice
Copyright (c) 2017 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
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.
Lennox, et al. Standards Track [Page 2]
RFC 8108 Multiple Media Streams in an RTP Session March 2017
Table of Contents
1. Introduction ....................................................4
2. Terminology .....................................................4
3. Use Cases for Multi-Stream Endpoints ............................4
3.1. Endpoints with Multiple Capture Devices ....................4
3.2. Multiple Media Types in a Single RTP Session ...............5
3.3. Multiple Stream Mixers .....................................5
3.4. Multiple SSRCs for a Single Media Source ...................5
4. Use of RTP by Endpoints That Send Multiple Media Streams ........6
5. Use of RTCP by Endpoints That Send Multiple Media Streams .......6
5.1. RTCP Reporting Requirement .................................7
5.2. Initial Reporting Interval .................................7
5.3. Aggregation of Reports into Compound RTCP Packets ..........8
5.3.1. Maintaining AVG_RTCP_SIZE ...........................9
5.3.2. Scheduling RTCP when Aggregating Multiple SSRCs ....10
5.4. Use of RTP/AVPF or RTP/SAVPF Feedback .....................13
5.4.1. Choice of SSRC for Feedback Packets ................13
5.4.2. Scheduling an RTCP Feedback Packet .................14
6. Adding and Removing SSRCs ......................................15
6.1. Adding RTP Streams ........................................16
6.2. Removing RTP Streams ......................................16
7. RTCP Considerations for Streams with Disparate Rates ...........17
7.1. Timing Out SSRCs ..........................................19
7.1.1. Problems with the RTP/AVPF T_rr_interval
Parameter ..........................................19
7.1.2. Avoiding Premature Timeout .........................20
7.1.3. Interoperability between RTP/AVP and RTP/AVPF ......21
7.1.4. Updated SSRC Timeout Rules .........................22
7.2. Tuning RTCP Transmissions .................................22
7.2.1. RTP/AVP and RTP/SAVP ...............................22
Show full document text