Multimedia Congestion Control: Circuit Breakers for Unicast RTP Sessions
draft-ietf-avtcore-rtp-circuit-breakers-18

Document Type Active Internet-Draft (avtcore WG)
Last updated 2016-08-18
Replaces draft-perkins-avtcore-rtp-circuit-breakers
Stream IETF
Intended RFC status Proposed Standard
Formats plain text pdf html bibtex
Stream WG state Submitted to IESG for Publication Dec 2015
Document shepherd Magnus Westerlund
Shepherd write-up Show (last changed 2016-02-17)
IESG IESG state RFC Ed Queue
Consensus Boilerplate Yes
Telechat date
Responsible AD Ben Campbell
Send notices to (None)
IANA IANA review state Version Changed - Review Needed
IANA action state No IC
RFC Editor RFC Editor state EDIT
AVTCORE Working Group                                         C. Perkins
Internet-Draft                                     University of Glasgow
Updates: 3550 (if approved)                                     V. Singh
Intended status: Standards Track                            callstats.io
Expires: February 19, 2017                               August 18, 2016

Multimedia Congestion Control: Circuit Breakers for Unicast RTP Sessions
               draft-ietf-avtcore-rtp-circuit-breakers-18

Abstract

   The Real-time Transport Protocol (RTP) is widely used in telephony,
   video conferencing, and telepresence applications.  Such applications
   are often run on best-effort UDP/IP networks.  If congestion control
   is not implemented in these applications, then network congestion can
   lead to uncontrolled packet loss, and a resulting deterioration of
   the user's multimedia experience.  The congestion control algorithm
   acts as a safety measure, stopping RTP flows from using excessive
   resources, and protecting the network from overload.  At the time of
   this writing, however, while there are several proprietary solutions,
   there is no standard algorithm for congestion control of interactive
   RTP flows.

   This document does not propose a congestion control algorithm.  It
   instead defines a minimal set of RTP circuit breakers: conditions
   under which an RTP sender needs to stop transmitting media data, to
   protect the network from excessive congestion.  It is expected that,
   in the absence of long-lived excessive congestion, RTP applications
   running on best-effort IP networks will be able to operate without
   triggering these circuit breakers.  To avoid triggering the RTP
   circuit breaker, any standards-track congestion control algorithms
   defined for RTP will need to operate within the envelope set by these
   RTP circuit breaker algorithms.

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
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any

Perkins & Singh         Expires February 19, 2017               [Page 1]
Internet-Draft            RTP Circuit Breakers               August 2016

   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 February 19, 2017.

Copyright Notice

   Copyright (c) 2016 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
   (http://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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Background  . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   6
   4.  RTP Circuit Breakers for Systems Using the RTP/AVP Profile  .   7
     4.1.  RTP/AVP Circuit Breaker #1: RTCP Timeout  . . . . . . . .  10
     4.2.  RTP/AVP Circuit Breaker #2: Media Timeout . . . . . . . .  11
     4.3.  RTP/AVP Circuit Breaker #3: Congestion  . . . . . . . . .  12
     4.4.  RTP/AVP Circuit Breaker #4: Media Usability . . . . . . .  16
     4.5.  Ceasing Transmission  . . . . . . . . . . . . . . . . . .  17
   5.  RTP Circuit Breakers and the RTP/AVPF and RTP/SAVPF Profiles   17
   6.  Impact of RTCP Extended Reports (XR)  . . . . . . . . . . . .  19
   7.  Impact of Explicit Congestion Notification (ECN)  . . . . . .  19
   8.  Impact of Bundled Media and Layered Coding  . . . . . . . . .  19
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  20
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  20
   11. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  21
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  21
     12.1.  Normative References . . . . . . . . . . . . . . . . . .  21
     12.2.  Informative References . . . . . . . . . . . . . . . . .  22
Show full document text