RFC 9297 - HTTP Datagrams and the Capsule Protocol

Published: August 2022
Status: Standards Track
Authors: D. Schinazi (Google LLC), L. Pardue (Cloudflare)

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Abstract

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

In HTTP/3, HTTP Datagrams can be sent unreliably using the QUIC DATAGRAM extension. When the QUIC DATAGRAM frame is unavailable or undesirable, HTTP Datagrams can be sent using the Capsule Protocol, which is 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.

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Table of Contents

• 1. Introduction
  • 1.1 Conventions and Definitions
• 2. HTTP Datagrams
  • 2.1 HTTP/3 Datagrams
    • 2.1.1 The SETTINGS_H3_DATAGRAM HTTP/3 Setting
  • 2.2 HTTP Datagrams Using Capsules
• 3. Capsules
  • 3.1 HTTP Data Streams
  • 3.2 The Capsule Protocol
  • 3.3 Error Handling
  • 3.4 The Capsule-Protocol Header Field
  • 3.5 The DATAGRAM Capsule
• 4. Security Considerations
• 5. IANA Considerations
  • 5.1 HTTP/3 Setting
  • 5.2 HTTP/3 Error Code
  • 5.3 HTTP Header Field Name
  • 5.4 Capsule Types
• 6. References
  • 6.1 Normative References
  • 6.2 Informative References
• Acknowledgments
• Authors' Addresses

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Related Resources

• Official RFC: RFC 9297
• Datatracker: RFC 9297 Info
• Errata: RFC Editor Errata

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