RTP Retransmission Payload Format
RFC 4588
Document | Type | RFC - Proposed Standard (July 2006; No errata) | |
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Authors | David Leon , Rolf Hakenberg , Jose Rey , Akihiro Miyazaki , Victor Varsa | ||
Last updated | 2020-07-29 | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 4588 (Proposed Standard) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Allison Mankin | ||
Send notices to | <csp@csperkins.org>, <magnus.westerlund@ericsson.com> |
Network Working Group J. Rey Request for Comments: 4588 Panasonic Category: Standards Track D. Leon Consultant A. Miyazaki Panasonic V. Varsa Nokia R. Hakenberg Panasonic July 2006 RTP Retransmission Payload Format 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. Copyright Notice Copyright (C) The Internet Society (2006). Abstract RTP retransmission is an effective packet loss recovery technique for real-time applications with relaxed delay bounds. This document describes an RTP payload format for performing retransmissions. Retransmitted RTP packets are sent in a separate stream from the original RTP stream. It is assumed that feedback from receivers to senders is available. In particular, it is assumed that Real-time Transport Control Protocol (RTCP) feedback as defined in the extended RTP profile for RTCP-based feedback (denoted RTP/AVPF) is available in this memo. Rey, et al. Standards Track [Page 1] RFC 4588 RTP Retransmission Payload Format July 2006 Table of Contents 1. Introduction ....................................................3 2. Terminology .....................................................3 3. Requirements and Design Rationale for a Retransmission Scheme ...4 3.1. Multiplexing Scheme Choice .................................6 4. Retransmission Payload Format ...................................7 5. Association of Retransmission and Original Streams ..............9 5.1. Retransmission Session Sharing .............................9 5.2. CNAME Use ..................................................9 5.3. Association at the Receiver ................................9 6. Use with the Extended RTP Profile for RTCP-based Feedback ......11 6.1. RTCP at the Sender ........................................11 6.2. RTCP Receiver Reports .....................................11 6.3. Retransmission Requests ...................................12 6.4. Timing Rules ..............................................13 7. Congestion Control .............................................13 8. Retransmission Payload Format MIME Type Registration ...........15 8.1. Introduction ..............................................15 8.2. Registration of audio/rtx .................................16 8.3. Registration of video/rtx .................................17 8.4. Registration of text/rtx ..................................18 8.5. Registration of application/rtx ...........................19 8.6. Mapping to SDP ............................................20 8.7. SDP Description with Session-Multiplexing .................20 8.8. SDP Description with SSRC-Multiplexing ....................21 9. RTSP Considerations ............................................22 9.1. RTSP Control with SSRC-Multiplexing .......................22 9.2. RTSP Control with Session-Multiplexing ....................22 9.3. RTSP Control of the Retransmission Stream .................23 9.4. Cache Control .............................................23 10. Implementation Examples .......................................23 10.1. A Minimal Receiver Implementation Example ................24 10.2. Retransmission of Layered Encoded Media in Multicast .....25 11. IANA Considerations ...........................................26 12. Security Considerations .......................................26 13. Acknowledgements ..............................................27 14. References ....................................................27 14.1. Normative References .....................................27 14.2. Informative References ...................................28 Appendix A. How to Control the Number of Rtxs. per Packet .........29 Rey, et al. Standards Track [Page 2]Show full document text