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HTTP Datagrams and the Capsule Protocol
RFC 9297

Approval announcement
Draft of message to be sent after approval:


From: The IESG <>
To: IETF-Announce <>
Cc: The IESG <>,,,,,,
Subject: Protocol Action: 'HTTP Datagrams and the Capsule Protocol' to Proposed Standard (draft-ietf-masque-h3-datagram-11.txt)

The IESG has approved the following document:
- 'HTTP Datagrams and the Capsule Protocol'
  (draft-ietf-masque-h3-datagram-11.txt) as Proposed Standard

This document is the product of the Multiplexed Application Substrate over
QUIC Encryption Working Group.

The IESG contact persons are Zaheduzzaman Sarker and Martin Duke.

A URL of this Internet Draft is:

Ballot Text

Technical Summary

This document describes HTTP Datagrams, a convention for conveying multiplexed, potentially unreliable datagrams inside an HTTP connection.

In HTTP/3, HTTP Datagrams can be conveyed natively using the QUIC DATAGRAM extension. When the QUIC DATAGRAM frame is unavailable or undesirable, they can be sent using the Capsule Protocol, a more general convention for conveying data in HTTP connections.

HTTP Datagrams and the Capsule Protocol are intended for use by HTTP extensions, not applications.

Working Group Summary

There was some initial controversy around the role of HTTP intermediaries in
the protocol (are they explicit? what role do they play? what are they allowed
to do or not do with messages sent up or downstream?), though these concerns
were resolved as a byproduct of a Design Team that worked on the document.

Document Quality

Yes, there are several interoperable implementations of the document. Some of
them are open source [1,2] whereas others are closed source. Other
implementations can be provided upon request.


This document is relevant to the QUIC and WebTransport WGs, and both WGs were
included on the WGLC thread, so we believe this review has occurred.


   The Document Shepherd is Christopher A. Wood. The Responsible
   AD is Martin Duke.

RFC Editor Note