Using Simulcast in SDP and RTP Sessions
draft-ietf-mmusic-sdp-simulcast-12
| Document | Type | Active Internet-Draft (mmusic WG) | |
|---|---|---|---|
| Last updated | 2018-05-21 (latest revision 2018-04-10) | ||
| Replaces | draft-burman-mmusic-sdp-simulcast | ||
| Stream | IETF | ||
| Intended RFC status | Proposed Standard | ||
| Formats | plain text xml pdf html bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication (wg milestone: Oct 2017 - Submit Using Simulca... ) | |
| Document shepherd | Flemming Andreasen | ||
| Shepherd write-up | Show (last changed 2018-03-06) | ||
| IESG | IESG state | IESG Evaluation | |
| Consensus Boilerplate | Yes | ||
| Telechat date |
On agenda of 2018-06-21 IESG telechat
Needs 8 more YES or NO OBJECTION positions to pass. |
||
| Responsible AD | Ben Campbell | ||
| Send notices to | (None) | ||
| IANA | IANA review state | IANA OK - Actions Needed | |
| IANA action state | None | ||
Network Working Group B. Burman
Internet-Draft M. Westerlund
Intended status: Standards Track Ericsson
Expires: October 12, 2018 S. Nandakumar
M. Zanaty
Cisco
April 10, 2018
Using Simulcast in SDP and RTP Sessions
draft-ietf-mmusic-sdp-simulcast-12
Abstract
In some application scenarios it may be desirable to send multiple
differently encoded versions of the same media source in different
RTP streams. This is called simulcast. This document describes how
to accomplish simulcast in RTP and how to signal it in SDP. The
described solution uses an RTP/RTCP identification method to identify
RTP streams belonging to the same media source, and makes an
extension to SDP to relate those RTP streams as being different
simulcast formats of that media source. The SDP extension consists
of a new media level SDP attribute that expresses capability to send
and/or receive simulcast RTP streams.
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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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 October 12, 2018.
Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved.
Burman, et al. Expires October 12, 2018 [Page 1]
Internet-Draft Simulcast April 2018
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Requirements Language . . . . . . . . . . . . . . . . . . 5
3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Reaching a Diverse Set of Receivers . . . . . . . . . . . 6
3.2. Application Specific Media Source Handling . . . . . . . 7
3.3. Receiver Media Source Preferences . . . . . . . . . . . . 7
4. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5. Detailed Description . . . . . . . . . . . . . . . . . . . . 9
5.1. Simulcast Attribute . . . . . . . . . . . . . . . . . . . 10
5.2. Simulcast Capability . . . . . . . . . . . . . . . . . . 11
5.3. Offer/Answer Use . . . . . . . . . . . . . . . . . . . . 13
5.3.1. Generating the Initial SDP Offer . . . . . . . . . . 13
5.3.2. Creating the SDP Answer . . . . . . . . . . . . . . . 13
5.3.3. Offerer Processing the SDP Answer . . . . . . . . . . 14
5.3.4. Modifying the Session . . . . . . . . . . . . . . . . 15
5.4. Use with Declarative SDP . . . . . . . . . . . . . . . . 15
5.5. Relating Simulcast Streams . . . . . . . . . . . . . . . 15
5.6. Signaling Examples . . . . . . . . . . . . . . . . . . . 16
5.6.1. Single-Source Client . . . . . . . . . . . . . . . . 16
5.6.2. Multi-Source Client . . . . . . . . . . . . . . . . . 18
5.6.3. Simulcast and Redundancy . . . . . . . . . . . . . . 20
6. RTP Aspects . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.1. Outgoing from Endpoint with Media Source . . . . . . . . 23
6.2. RTP Middlebox to Receiver . . . . . . . . . . . . . . . . 23
6.2.1. Media-Switching Mixer . . . . . . . . . . . . . . . . 24
6.2.2. Selective Forwarding Middlebox . . . . . . . . . . . 26
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