Differentiated Services Code Point (DSCP) Packet Markings for WebRTC QoS
RFC 8837

Document Type RFC - Proposed Standard (January 2021; No errata)
Authors Paul Jones  , Subha Dhesikan  , Cullen Jennings  , Dan Druta 
Last updated 2021-01-18
Replaces draft-dhesikan-tsvwg-rtcweb-qos
Stream IETF
Formats plain text html xml pdf htmlized bibtex
Stream WG state Submitted to IESG for Publication
Document shepherd David Black
Shepherd write-up Show (last changed 2016-05-11)
IESG IESG state RFC 8837 (Proposed Standard)
Action Holders
Consensus Boilerplate Yes
Telechat date
Responsible AD Magnus Westerlund
Send notices to "David L. Black" <david.black@emc.com>
IANA IANA review state Version Changed - Review Needed
IANA action state No IANA Actions

Internet Engineering Task Force (IETF)                          P. Jones
Request for Comments: 8837                                 Cisco Systems
Category: Standards Track                                    S. Dhesikan
ISSN: 2070-1721                                               Individual
                                                             C. Jennings
                                                           Cisco Systems
                                                                D. Druta
                                                            January 2021

Differentiated Services Code Point (DSCP) Packet Markings for WebRTC QoS


   Networks can provide different forwarding treatments for individual
   packets based on Differentiated Services Code Point (DSCP) values on
   a per-hop basis.  This document provides the recommended DSCP values
   for web browsers to use for various classes of Web Real-Time
   Communication (WebRTC) traffic.

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

Copyright Notice

   Copyright (c) 2021 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
   2.  Terminology
   3.  Relation to Other Specifications
   4.  Inputs
   5.  DSCP Mappings
   6.  Security Considerations
   7.  IANA Considerations
   8.  Downward References
   9.  References
     9.1.  Normative References
     9.2.  Informative References
   Authors' Addresses

1.  Introduction

   Differentiated Services Code Point (DSCP) [RFC2474] packet marking
   can help provide QoS in some environments.  This specification
   provides default packet marking for browsers that support WebRTC
   applications, but does not change any advice or requirements in other
   RFCs.  The contents of this specification are intended to be a simple
   set of implementation recommendations based on previous RFCs.

   Networks in which these DSCP markings are beneficial (likely to
   improve QoS for WebRTC traffic) include:

   1.  Private, wide-area networks.  Network administrators have control
       over remarking packets and treatment of packets.

   2.  Residential Networks.  If the congested link is the broadband
       uplink in a cable or DSL scenario, residential routers/NAT often
       support preferential treatment based on DSCP.

   3.  Wireless Networks.  If the congested link is a local wireless
       network, marking may help.

   There are cases where these DSCP markings do not help but, aside from
   possible priority inversion for "Less-than-Best-Effort traffic" (see
   Section 5), they seldom make things worse if packets are marked

   DSCP values are, in principle, site specific with each site selecting
   its own code points for controlling per-hop behavior to influence the
   QoS for transport-layer flows.  However, in the WebRTC use cases, the
   browsers need to set them to something when there is no site-specific
   information.  This document describes a subset of DSCP code point
   values drawn from existing RFCs and common usage for use with WebRTC
   applications.  These code points are intended to be the default
   values used by a WebRTC application.  While other values could be
   used, using a non-default value may result in unexpected per-hop
   behavior.  It is RECOMMENDED that WebRTC applications use non-default
   values only in private networks that are configured to use different

   This specification defines inputs that are provided by the WebRTC
   application hosted in the browser that aid the browser in determining
   how to set the various packet markings.  The specification also
   defines the mapping from abstract QoS policies (flow type, priority
   level) to those packet markings.
Show full document text