Codec Control Messages in the RTP Audio-Visual Profile with Feedback (AVPF)
RFC 5104
| Document | Type |
RFC - Proposed Standard
(February 2008; No errata)
Updated by RFC 7728
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Replaces | draft-wenger-avt-avpf-ccm | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 5104 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Cullen Jennings | ||
| Send notices to | (None) | ||
Network Working Group S. Wenger
Request for Comments: 5104 U. Chandra
Category: Standards Track Nokia
M. Westerlund
B. Burman
Ericsson
February 2008
Codec Control Messages in the
RTP Audio-Visual Profile with Feedback (AVPF)
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.
Abstract
This document specifies a few extensions to the messages defined in
the Audio-Visual Profile with Feedback (AVPF). They are helpful
primarily in conversational multimedia scenarios where centralized
multipoint functionalities are in use. However, some are also usable
in smaller multicast environments and point-to-point calls.
The extensions discussed are messages related to the ITU-T Rec. H.271
Video Back Channel, Full Intra Request, Temporary Maximum Media
Stream Bit Rate, and Temporal-Spatial Trade-off.
Wenger, et al. Standards Track [Page 1]
RFC 5104 Codec Control Messages in AVPF February 2008
Table of Contents
1. Introduction ....................................................4
2. Definitions .....................................................5
2.1. Glossary ...................................................5
2.2. Terminology ................................................5
2.3. Topologies .................................................8
3. Motivation ......................................................8
3.1. Use Cases ..................................................9
3.2. Using the Media Path ......................................11
3.3. Using AVPF ................................................11
3.3.1. Reliability ........................................12
3.4. Multicast .................................................12
3.5. Feedback Messages .........................................12
3.5.1. Full Intra Request Command .........................12
3.5.1.1. Reliability ...............................13
3.5.2. Temporal-Spatial Trade-off Request and
Notification .......................................14
3.5.2.1. Point-to-Point ............................15
3.5.2.2. Point-to-Multipoint Using
Multicast or Translators ..................15
3.5.2.3. Point-to-Multipoint Using RTP Mixer .......15
3.5.2.4. Reliability ...............................16
3.5.3. H.271 Video Back Channel Message ...................16
3.5.3.1. Reliability ...............................19
3.5.4. Temporary Maximum Media Stream Bit Rate
Request and Notification ...........................19
3.5.4.1. Behavior for Media Receivers Using TMMBR ..21
3.5.4.2. Algorithm for Establishing Current
Limitations ...............................23
3.5.4.3. Use of TMMBR in a Mixer-Based
Multipoint Operation ......................29
3.5.4.4. Use of TMMBR in Point-to-Multipoint Using
Multicast or Translators ..................30
3.5.4.5. Use of TMMBR in Point-to-Point Operation ..31
3.5.4.6. Reliability ...............................31
4. RTCP Receiver Report Extensions ................................32
4.1. Design Principles of the Extension Mechanism ..............32
4.2. Transport Layer Feedback Messages .........................33
4.2.1. Temporary Maximum Media Stream Bit Rate
Request (TMMBR) ....................................34
4.2.1.1. Message Format ............................34
4.2.1.2. Semantics .................................35
4.2.1.3. Timing Rules ..............................39
4.2.1.4. Handling in Translators and Mixers ........39
4.2.2. Temporary Maximum Media Stream Bit Rate
Notification (TMMBN) ...............................39
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