Codec Control Messages in the RTP Audio-Visual Profile with Feedback (AVPF)
RFC 5104
Document | Type | RFC - Proposed Standard (February 2008; No errata) | |
---|---|---|---|
Authors | Bo Burman , Stephan Wenger , Magnus Westerlund , Umesh Chandra | ||
Last updated | 2018-12-20 | ||
Replaces | draft-wenger-avt-avpf-ccm | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 5104 (Proposed Standard) | |
Action Holders |
(None)
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||
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 4.2.2.1. Message Format ............................39 Wenger, et al. Standards Track [Page 2]Show full document text