MASQUE extension for signaling media bitrate
draft-ihlar-masque-sconepro-mediabitrate-00

Multiplexed Application Substrate over QUIC Encryption          M. Ihlar
Internet-Draft                                              M. Kühlewind
Intended status: Standards Track                                Ericsson
Expires: 12 August 2024                                  9 February 2024

              MASQUE extension for signaling media bitrate
              draft-ihlar-masque-sconepro-mediabitrate-00

Abstract

   This document specifies a new Capsule (RFC9297) that can be used with
   CONNECT-UDP (RFC9298), CONNECT-IP (RFC9484), or other future CONNECT
   extensions to signal the available bitrate for media traffic that is
   proxied through an HTTP server.  This information can be used by a
   media application to regulate its media bitrate in accordance with a
   network policy, as an alternative to in-network traffic shaping.

About This Document

   This note is to be removed before publishing as an RFC.

   Status information for this document may be found at
   https://datatracker.ietf.org/doc/draft-ihlar-masque-sconepro-
   mediabitrate/.

   Discussion of this document takes place on the Multiplexed
   Application Substrate over QUIC Encryption Working Group mailing list
   (mailto:masque@ietf.org), which is archived at
   https://mailarchive.ietf.org/arch/browse/masque/.  Subscribe at
   https://www.ietf.org/mailman/listinfo/masque/.

   Source for this draft and an issue tracker can be found at
   https://github.com/mirjak/draft-masque-mediabitrate.

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 https://datatracker.ietf.org/drafts/current/.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions and Definitions . . . . . . . . . . . . . . . . .   3
   3.  Indicating Support for Media Bitrate Signaling  . . . . . . .   3
   4.  MEDIA_BITRATE Capsule Type Format . . . . . . . . . . . . . .   3
   5.  Client Behaviour  . . . . . . . . . . . . . . . . . . . . . .   4
   6.  Proxy Behaviour . . . . . . . . . . . . . . . . . . . . . . .   4
   7.  Performance Considerations  . . . . . . . . . . . . . . . . .   4
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
     9.1.  Capsule types . . . . . . . . . . . . . . . . . . . . . .   4
     9.2.  HTTP headers  . . . . . . . . . . . . . . . . . . . . . .   5
   10. Normative References  . . . . . . . . . . . . . . . . . . . .   5
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   This document specifies a new Capsule (RFC9297) that can be used with
   CONNECT-UDP (RFC9298), CONNECT-IP (RFC9484), or other future CONNECT
   extensions to signal the available bitrate for media traffic that is
   proxied through an HTTP server.  This information can be used by a
   media application to regulate its media bitrate in accordance with a
   network policy, as an alternative to in-network traffic shaping.

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   The extension can be used with the HTTP CONNECT method when the
   :protocol pseudo header is equal to "connect-udp" or "connect-ip" and
   with future CONNECT protocols that use the Capsule Protocol.

2.  Conventions and Definitions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  Indicating Support for Media Bitrate Signaling

   A client who wishes to receive media bitrate capsules can indicate
   support by sending a request header with the boolean-valued Item
   Structured Field "Media-Bitrate: ?1".  The HTTP proxy indicates
   support by sending a response header with the boolean-valued Item
   Structured Field "Media-Bitrate: ?1" See Section 3.3.6 of [RFC8941]
   for information about the boolean format.

   Once support has been established, a proxy MAY send MEDIA_BITRATE
   capsules at any time during the lifetime of the stream that
   originated the request.

4.  MEDIA_BITRATE Capsule Type Format

   The MEDIA_BITRATE Capsule has the following format:

   MEDIA_BITRATE Capsule {
     Type (i) = MEDIA_BITRATE,
     Length (i)
     Media Bitrate (i)
     [Average Window (i)]
   }

   The capsule has the following fields:

   Media Bitrate: Indicates the average bitrate that is supported by the
   network without traffic shaping.

   Average Window: Indicates the duration over which the bitrate is
   enforced.  The largest allowed burst is given by Media Bitrate *
   Average window.  This field is optional.

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5.  Client Behaviour

   A client that receives media bitrate capsules needs to make the
   information available to a media application, this is implementation
   specific and out of scope for this document.  A media application can
   use the information to select a media track that conforms with the
   specified bitrate.  How this is done and whether an application
   client needs to explicitly coordinate with an application server is
   out of scope for this document.

6.  Proxy Behaviour

   A proxy that sends media bitrate capsules needs to be tightly
   integrated with the access network infrastructure and policy
   framework.  A proxy that sends media bitrate capsules does so as an
   alternative to traffic shaping, the policies that govern shaping
   behaviour can be used to determine the values sent with media bitrate
   capsules.

   A proxy might still apply shaping or policing to traffic that is
   breaching the policy in order to ensure that the bitrate policy is
   respected.  In this case, it is RECOMMENDED that the proxy uses an
   averaging window that is sufficiently long to allow data transmission
   bursts that make full use of the available network capacity.  A proxy
   can SHOULD the Average Window field in the media bitrate capsule to
   inform the client about how it enforces bitrates.

7.  Performance Considerations

   This protocol is intended to provide policy indications to
   applications traversing a network.  Using HTTP proxying for this
   purpose does add overhead in terms of CPU, memory and MTU.  It is
   RECOMMENDED that this solution is used together with QUIC-Aware
   proxying [I-D.ietf-masque-quic-proxy] whenever possible.

8.  Security Considerations

   TODO Security

9.  IANA Considerations

9.1.  Capsule types

   This document adds following entries to the "HTTP Capsule Types"
   registry:

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                +===============+=======+=================+
                | Capsule Type  | Value | Specification   |
                +===============+=======+=================+
                | MEDIA-BITRATE | TBD   | (This document) |
                +---------------+-------+-----------------+

                   Table 1: New Capsule Type to register

9.2.  HTTP headers

   This document adds following entry to the "Hypertext Transfer
   Protocol (HTTP) Field Name Registry":

   +===============+==========+===========+=================+==========+
   | Field Name    | Template | Status    | Reference       | Comments |
   +===============+==========+===========+=================+==========+
   | Media-Bitrate |          | permanent | (This           |          |
   |               |          |           | document)       |          |
   +---------------+----------+-----------+-----------------+----------+

                    Table 2: HTTP Field Name to register

10.  Normative References

   [I-D.ietf-masque-quic-proxy]
              Pauly, T., Rosenberg, E., and D. Schinazi, "QUIC-Aware
              Proxying Using HTTP", Work in Progress, Internet-Draft,
              draft-ietf-masque-quic-proxy-00, 17 August 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-masque-
              quic-proxy-00>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/rfc/rfc2119>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.

   [RFC8941]  Nottingham, M. and P. Kamp, "Structured Field Values for
              HTTP", RFC 8941, DOI 10.17487/RFC8941, February 2021,
              <https://www.rfc-editor.org/rfc/rfc8941>.

Acknowledgments

   TODO acknowledge.

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Authors' Addresses

   Marcus Ihlar
   Ericsson
   Email: marcus.ihlar@ericsson.com

   Mirja Kühlewind
   Ericsson
   Email: mirja.kuehlewind@ericsson.com

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