HTTPbis M. Bishop
Internet-Draft Microsoft
Intended status: Standards Track July 24, 2017
Expires: January 25, 2018



[RFC7838] defines the ALTSVC frame for HTTP/2 [RFC7540]. This frame is equally applicable to HTTP/QUIC ([I-D.ietf-quic-http]), but needs to be separately registered. This document describes the ALTSVC frame for HTTP/QUIC.

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Table of Contents

1. Introduction

[RFC7838] defines HTTP Alternative Services, which allow an origin’s resources to be authoritatively available at a separate network location, possibly accessed with a different protocol configuration. It defines two mechanisms for transporting such information, an HTTP response header and an HTTP/2 frame type.

[I-D.ietf-quic-http] describes the required updates for HTTP/2 frames to be used with HTTP/QUIC. Only a few modifications are required for the ALTSVC frame. No modifications are required for the “Alt-Svc” header field.


The ALTSVC HTTP/QUIC frame advertises the availability of an alternative service to an HTTP/QUIC client.

An ALTSVC frame from a server to a client on stream 1 (not 0, as in HTTP/2) indicates that the conveyed alternative service is associated with the origin contained in the Origin field of the frame.

An ALTSVC frame from a server to a client on a stream other than stream 1 indicates that the conveyed alternative service is associated with the origin of that stream.

The layout and semantics of the frame are identical to those of the HTTP/2 frame defined in [RFC7838]. The ALTSVC frame type is 0xa (decimal 10), as in HTTP/2.

3. Security Considerations

This document introduces no new security considerations beyond those discussed in [RFC7838] and [I-D.ietf-quic-http].

4. IANA Considerations

This document registers the ALTSVC frame type in the “HTTP/QUIC Frame Type” registry ([I-D.ietf-quic-http]).

Frame Type:
This document

5. References

5.1. Normative References

[I-D.ietf-quic-http] Bishop, M., "Hypertext Transfer Protocol (HTTP) over QUIC", Internet-Draft draft-ietf-quic-http-04, June 2017.
[RFC7838] Nottingham, M., McManus, P. and J. Reschke, "HTTP Alternative Services", RFC 7838, DOI 10.17487/RFC7838, April 2016.

5.2. Informative References

[RFC7540] Belshe, M., Peon, R. and M. Thomson, "Hypertext Transfer Protocol Version 2 (HTTP/2)", RFC 7540, DOI 10.17487/RFC7540, May 2015.

Author's Address

Mike Bishop Microsoft EMail: