Network Working Group                                        D. Schinazi
Internet-Draft                                                Google LLC
Intended status: Experimental                             March 12, 2020
Expires: September 13, 2020


                    Using QUIC Datagrams with HTTP/3
                   draft-schinazi-quic-h3-datagram-03

Abstract

   The QUIC DATAGRAM extension provides application protocols running
   over QUIC with a mechanism to send unreliable data while leveraging
   the security and congestion-control properties of QUIC.  However,
   QUIC DATAGRAM frames do not provide a means to demultiplex
   application contexts.  This document defines how to use QUIC DATAGRAM
   frames when the application protocol running over QUIC is HTTP/3 by
   adding an identifier at the start of the frame payload.

   Discussion of this work is encouraged to happen on the QUIC IETF
   mailing list quic@ietf.org [1] or on the GitHub repository which
   contains the draft: https://github.com/DavidSchinazi/draft-
   h3-datagram [2].

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/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   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 September 13, 2020.

Copyright Notice

   Copyright (c) 2020 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



Schinazi               Expires September 13, 2020               [Page 1]

 
Internet-Draft              HTTP/3 Datagrams                  March 2020


   (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
     1.1.  Conventions and Definitions . . . . . . . . . . . . . . .   2
   2.  HTTP/3 DATAGRAM Frame Format  . . . . . . . . . . . . . . . .   3
     2.1.  Flow Identifiers  . . . . . . . . . . . . . . . . . . . .   3
   3.  Flow Identifier Allocation  . . . . . . . . . . . . . . . . .   3
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     6.2.  URIs  . . . . . . . . . . . . . . . . . . . . . . . . . .   5
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   5
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   5

.  Introduction

   The QUIC DATAGRAM extension [DGRAM] provides application protocols
   running over QUIC [QUIC] with a mechanism to send unreliable data
   while leveraging the security and congestion-control properties of
   QUIC.  However, QUIC DATAGRAM frames do not provide a means to
   demultiplex application contexts.  This document defines how to use
   QUIC DATAGRAM frames when the application protocol running over QUIC
   is HTTP/3 [H3] by adding an identifier at the start of the frame
   payload.

   This design mimics the use of Stream Types in HTTP/3, which provide a
   demultiplexing identifier at the start of each unidirectional stream.

   Discussion of this work is encouraged to happen on the QUIC IETF
   mailing list quic@ietf.org [3] or on the GitHub repository which
   contains the draft: https://github.com/DavidSchinazi/draft-
   h3-datagram [4].

1.1.  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




Schinazi               Expires September 13, 2020               [Page 2]

 
Internet-Draft              HTTP/3 Datagrams                  March 2020


   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

.  HTTP/3 DATAGRAM Frame Format

   When used with HTTP/3, the Datagram Data field of QUIC DATAGRAM
   frames uses the following format:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     Flow Identifier (i)                     ...
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                 HTTP/3 Datagram Payload (*)                 ...
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 1: HTTP/3 DATAGRAM Frame Format

   Flow Identifier:  A variable-length integer indicating the Flow
      Identifier of the datagram (see Section 2.1).

   HTTP/3 Datagram Payload:  The payload of the datagram, whose
      semantics are defined by individual applications.

2.1.  Flow Identifiers

   Flow identifiers represent bidirectional flows of datagrams within a
   single QUIC connection.  These are conceptually similar to UDP ports
   and allow basic demultiplexing of application data.  The primary role
   of flow identifiers is to provide a standard mechanism for
   demultiplexing application data flows, which may be destined for
   different processing threads in the application, akin to UDP sockets.

   Beyond this, a sender SHOULD ensure that DATAGRAM frames within a
   single flow are transmitted in order relative to one another.  If
   multiple DATAGRAM frames can be packed into a single QUIC packet, the
   sender SHOULD group them by flow identifier to promote fate-sharing
   within a specific flow and improve the ability to process batches of
   datagram messages efficiently on the receiver.

.  Flow Identifier Allocation

   Implementations of HTTP/3 that support the DATAGRAM extension MUST
   provide a flow identifier allocation service.  That service will
   allow applications co-located with HTTP/3 to request a unique flow
   identifier that they can subsequently use for their own purposes.
   The HTTP/3 implementation will then parse the flow identifier of




Schinazi               Expires September 13, 2020               [Page 3]

 
Internet-Draft              HTTP/3 Datagrams                  March 2020


   incoming DATAGRAM frames and use it to deliver the frame to the
   appropriate application.

   Even flow identifiers are client-initiated, while odd flow
   identifiers are server-initiated.  This means that an HTTP/3 client
   implementation of the flow identifier allocation service MUST only
   provide even identifiers, while a server implementation MUST only
   provide odd identifiers.  Note that, once allocated, any flow
   identifier can be used by both client and server - only allocation
   carries separate namespaces to avoid requiring synchronization.

.  Security Considerations

   This document currently does not have additional security
   considerations beyond those defined in [QUIC] and [DGRAM].

.  IANA Considerations

   This document has no IANA actions.

.  References

6.1.  Normative References

   [DGRAM]    Pauly, T., Kinnear, E., and D. Schinazi, "An Unreliable
              Datagram Extension to QUIC", draft-ietf-quic-datagram-00
              (work in progress), February 2020.

   [H3]       Bishop, M., "Hypertext Transfer Protocol Version 3
              (HTTP/3)", draft-ietf-quic-http-27 (work in progress),
              February 2020.

   [QUIC]     Iyengar, J. and M. Thomson, "QUIC: A UDP-Based Multiplexed
              and Secure Transport", draft-ietf-quic-transport-27 (work
              in progress), February 2020.

   [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/info/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/info/rfc8174>.







Schinazi               Expires September 13, 2020               [Page 4]

 
Internet-Draft              HTTP/3 Datagrams                  March 2020


6.2.  URIs

   [] mailto:quic@ietf.org

   [] https://github.com/DavidSchinazi/draft-h3-datagram

   [] mailto:quic@ietf.org

   [] https://github.com/DavidSchinazi/draft-h3-datagram

Acknowledgments

   The DATAGRAM frame identifier was previously part of the DATAGRAM
   frame definition itself, the author would like to acknowledge the
   authors of that document and the members of the IETF QUIC working
   group for their suggestions.

Author's Address

   David Schinazi
   Google LLC
   1600 Amphitheatre Parkway
   Mountain View, California 94043
   United States of America

   Email: dschinazi.ietf@gmail.com

























Schinazi               Expires September 13, 2020               [Page 5]