A General Mechanism for RTP Header Extensions
RFC 8285
Document | Type |
RFC - Proposed Standard
(October 2017; No errata)
Obsoletes RFC 5285
|
|
---|---|---|---|
Authors | David Singer , HariKishan Desineni , Roni Even | ||
Last updated | 2017-10-25 | ||
Replaces | draft-even-avtcore-rfc5285-bis | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Magnus Westerlund | ||
Shepherd write-up | Show (last changed 2017-03-07) | ||
IESG | IESG state | RFC 8285 (Proposed Standard) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Ben Campbell | ||
Send notices to | "Magnus Westerlund" <magnus.westerlund@ericsson.com> | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | RFC-Ed-Ack |
Internet Engineering Task Force (IETF) D. Singer Request for Comments: 8285 Apple, Inc. Obsoletes: 5285 H. Desineni Category: Standards Track Qualcomm ISSN: 2070-1721 R. Even, Ed. Huawei Technologies October 2017 A General Mechanism for RTP Header Extensions Abstract This document provides a general mechanism to use the header extension feature of RTP (the Real-time Transport Protocol). It provides the option to use a small number of small extensions in each RTP packet, where the universe of possible extensions is large and registration is decentralized. The actual extensions in use in a session are signaled in the setup information for that session. This document obsoletes RFC 5285. 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 https://www.rfc-editor.org/info/rfc8285. Singer, et al. Standards Track [Page 1] RFC 8285 RTP Header Extensions October 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 (https://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. Table of Contents 1. Introduction ....................................................3 2. Requirements Notation ...........................................3 3. Design Goals ....................................................3 4. Packet Design ...................................................4 4.1. General ....................................................4 4.1.1. Transmission Considerations .........................5 4.1.2. Header Extension Type Considerations ................6 4.2. One-Byte Header ............................................8 4.3. Two-Byte Header ............................................9 5. SDP Signaling Design ...........................................10 6. SDP Signaling for Support of Mixed One-Byte and Two-Byte Header Extensions ..........................................12 7. SDP Offer/Answer ...............................................13 8. BNF Syntax .....................................................17 9. Security Considerations ........................................17 10. IANA Considerations ...........................................18 10.1. Identifier Space for IANA to Manage ......................18 10.2. Registration of the SDP "extmap" Attribute ...............20 10.3. Registration of the SDP "extmap-allow-mixed" Attribute ...20 11. Changes from RFC 5285 .........................................21 12. References ....................................................21 12.1. Normative References .....................................21 12.2. Informative References ...................................23 Acknowledgments ...................................................24 Authors' Addresses ................................................25 Singer, et al. Standards Track [Page 2] RFC 8285 RTP Header Extensions October 2017 1. Introduction The RTP specification [RFC3550] provides a capability to extend the RTP header. Section 5.3.1 of [RFC3550] defines the header extension format and rules for its use. The existing header extension method permits at most one extension per RTP packet, identified by a 16-bit identifier and a 16-bit length field specifying the length of the header extension in 32-bit words. This mechanism has two conspicuous drawbacks. First, it permits only one header extension in a single RTP packet. Second, theShow full document text