Network Working Group                                        D. Schinazi
Internet-Draft                                                Google LLC
Intended status: Experimental                           October 21, 2019
Expires: April 23, 2020


                    Using QUIC Datagrams with HTTP/3
                   draft-schinazi-quic-h3-datagram-00

Abstract

   The QUIC DATAGRAM extension provides application protocols running
   over QUIC with a way 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 using them.  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.

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   This Internet-Draft will expire on April 23, 2020.

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   the Trust Legal Provisions and are provided without warranty as
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Table of Contents

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

.  Introduction

   The QUIC DATAGRAM extension [I-D.pauly-quic-datagram] provides
   application protocols running over QUIC [I-D.ietf-quic-transport]
   with a way 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 using
   them.  This document defines how to use QUIC DATAGRAM frames when the
   application protocol running over QUIC is HTTP/3
   [I-D.ietf-quic-http], 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.

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
   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:








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    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 effectively equivalent to UDP
   ports, that allow basic demultiplexing of application data.  The
   primary role of slow 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 will
   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
   incoming DATAGRAM frames and use it to deliver the frame to the
   appropriate application.

.  Security Considerations

   This document currently does not have additional security
   considerations on top of the ones defined in
   [I-D.ietf-quic-transport] and [I-D.pauly-quic-datagram].




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.  IANA Considerations

   This document has no IANA actions.

.  Normative References

   [I-D.ietf-quic-http]
              Bishop, M., "Hypertext Transfer Protocol Version 3
              (HTTP/3)", draft-ietf-quic-http-23 (work in progress),
              September 2019.

   [I-D.ietf-quic-transport]
              Iyengar, J. and M. Thomson, "QUIC: A UDP-Based Multiplexed
              and Secure Transport", draft-ietf-quic-transport-23 (work
              in progress), September 2019.

   [I-D.pauly-quic-datagram]
              Pauly, T., Kinnear, E., and D. Schinazi, "An Unreliable
              Datagram Extension to QUIC", draft-pauly-quic-datagram-03
              (work in progress), July 2019.

   [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>.

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





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