draft-ietf-quic-http-16.txt   draft-ietf-quic-http-latest.txt 
QUIC Working Group M. Bishop, Ed. QUIC Working Group M. Bishop, Ed.
Internet-Draft Akamai Internet-Draft Akamai
Intended status: Standards Track October 24, 2018 Intended status: Standards Track December 14, 2018
Expires: April 27, 2019 Expires: June 17, 2019
Hypertext Transfer Protocol (HTTP) over QUIC Hypertext Transfer Protocol Version 3 (HTTP/3)
draft-ietf-quic-http-16 draft-ietf-quic-http-latest
Abstract Abstract
The QUIC transport protocol has several features that are desirable The QUIC transport protocol has several features that are desirable
in a transport for HTTP, such as stream multiplexing, per-stream flow in a transport for HTTP, such as stream multiplexing, per-stream flow
control, and low-latency connection establishment. This document control, and low-latency connection establishment. This document
describes a mapping of HTTP semantics over QUIC. This document also describes a mapping of HTTP semantics over QUIC. This document also
identifies HTTP/2 features that are subsumed by QUIC, and describes identifies HTTP/2 features that are subsumed by QUIC, and describes
how HTTP/2 extensions can be ported to QUIC. how HTTP/2 extensions can be ported to HTTP/3.
Note to Readers Note to Readers
Discussion of this draft takes place on the QUIC working group Discussion of this draft takes place on the QUIC working group
mailing list (quic@ietf.org), which is archived at mailing list (quic@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/search/?email_list=quic [1]. https://mailarchive.ietf.org/arch/search/?email_list=quic [1].
Working Group information can be found at https://github.com/quicwg Working Group information can be found at https://github.com/quicwg
[2]; source code and issues list for this draft can be found at [2]; source code and issues list for this draft can be found at
https://github.com/quicwg/base-drafts/labels/-http [3]. https://github.com/quicwg/base-drafts/labels/-http [3].
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 27, 2019. This Internet-Draft will expire on June 17, 2019.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Notational Conventions . . . . . . . . . . . . . . . . . 4 1.1. Notational Conventions . . . . . . . . . . . . . . . . . 4
2. Connection Setup and Management . . . . . . . . . . . . . . . 5 2. Connection Setup and Management . . . . . . . . . . . . . . . 5
2.1. Draft Version Identification . . . . . . . . . . . . . . 5 2.1. Draft Version Identification . . . . . . . . . . . . . . 5
2.2. Discovering an HTTP/QUIC Endpoint . . . . . . . . . . . . 5 2.2. Discovering an HTTP/3 Endpoint . . . . . . . . . . . . . 5
2.2.1. QUIC Version Hints . . . . . . . . . . . . . . . . . 6 2.2.1. QUIC Version Hints . . . . . . . . . . . . . . . . . 6
2.3. Connection Establishment . . . . . . . . . . . . . . . . 6 2.3. Connection Establishment . . . . . . . . . . . . . . . . 6
2.4. Connection Reuse . . . . . . . . . . . . . . . . . . . . 7 2.4. Connection Reuse . . . . . . . . . . . . . . . . . . . . 7
3. Stream Mapping and Usage . . . . . . . . . . . . . . . . . . 7 3. Stream Mapping and Usage . . . . . . . . . . . . . . . . . . 7
3.1. Bidirectional Streams . . . . . . . . . . . . . . . . . . 8 3.1. Bidirectional Streams . . . . . . . . . . . . . . . . . . 8
3.2. Unidirectional Streams . . . . . . . . . . . . . . . . . 8 3.2. Unidirectional Streams . . . . . . . . . . . . . . . . . 8
3.2.1. Control Streams . . . . . . . . . . . . . . . . . . . 9 3.2.1. Control Streams . . . . . . . . . . . . . . . . . . . 9
3.2.2. Push Streams . . . . . . . . . . . . . . . . . . . . 9 3.2.2. Push Streams . . . . . . . . . . . . . . . . . . . . 9
3.2.3. Reserved Stream Types . . . . . . . . . . . . . . . . 10 3.2.3. Reserved Stream Types . . . . . . . . . . . . . . . . 10
4. HTTP Framing Layer . . . . . . . . . . . . . . . . . . . . . 10 4. HTTP Framing Layer . . . . . . . . . . . . . . . . . . . . . 10
4.1. Frame Layout . . . . . . . . . . . . . . . . . . . . . . 10 4.1. Frame Layout . . . . . . . . . . . . . . . . . . . . . . 10
4.2. Frame Definitions . . . . . . . . . . . . . . . . . . . . 11 4.2. Frame Definitions . . . . . . . . . . . . . . . . . . . . 11
4.2.1. DATA . . . . . . . . . . . . . . . . . . . . . . . . 11 4.2.1. DATA . . . . . . . . . . . . . . . . . . . . . . . . 11
4.2.2. HEADERS . . . . . . . . . . . . . . . . . . . . . . . 12 4.2.2. HEADERS . . . . . . . . . . . . . . . . . . . . . . . 12
4.2.3. PRIORITY . . . . . . . . . . . . . . . . . . . . . . 12 4.2.3. PRIORITY . . . . . . . . . . . . . . . . . . . . . . 12
4.2.4. CANCEL_PUSH . . . . . . . . . . . . . . . . . . . . . 14 4.2.4. CANCEL_PUSH . . . . . . . . . . . . . . . . . . . . . 14
4.2.5. SETTINGS . . . . . . . . . . . . . . . . . . . . . . 15 4.2.5. SETTINGS . . . . . . . . . . . . . . . . . . . . . . 15
4.2.6. PUSH_PROMISE . . . . . . . . . . . . . . . . . . . . 17 4.2.6. PUSH_PROMISE . . . . . . . . . . . . . . . . . . . . 18
4.2.7. GOAWAY . . . . . . . . . . . . . . . . . . . . . . . 18 4.2.7. GOAWAY . . . . . . . . . . . . . . . . . . . . . . . 18
4.2.8. MAX_PUSH_ID . . . . . . . . . . . . . . . . . . . . . 19 4.2.8. MAX_PUSH_ID . . . . . . . . . . . . . . . . . . . . . 19
4.2.9. Reserved Frame Types . . . . . . . . . . . . . . . . 19 4.2.9. DUPLICATE_PUSH . . . . . . . . . . . . . . . . . . . 20
5. HTTP Request Lifecycle . . . . . . . . . . . . . . . . . . . 20 4.2.10. Reserved Frame Types . . . . . . . . . . . . . . . . 21
5.1. HTTP Message Exchanges . . . . . . . . . . . . . . . . . 20 5. HTTP Request Lifecycle . . . . . . . . . . . . . . . . . . . 21
5.1.1. Header Formatting and Compression . . . . . . . . . . 21 5.1. HTTP Message Exchanges . . . . . . . . . . . . . . . . . 21
5.1.2. Request Cancellation . . . . . . . . . . . . . . . . 22 5.1.1. Header Formatting and Compression . . . . . . . . . . 22
5.2. The CONNECT Method . . . . . . . . . . . . . . . . . . . 22 5.1.2. Request Cancellation . . . . . . . . . . . . . . . . 23
5.3. Request Prioritization . . . . . . . . . . . . . . . . . 23
5.3.1. Placeholders . . . . . . . . . . . . . . . . . . . . 24 5.2. The CONNECT Method . . . . . . . . . . . . . . . . . . . 24
5.3.2. Priority Tree Maintenance . . . . . . . . . . . . . . 24 5.3. Request Prioritization . . . . . . . . . . . . . . . . . 25
5.4. Server Push . . . . . . . . . . . . . . . . . . . . . . . 25 5.3.1. Placeholders . . . . . . . . . . . . . . . . . . . . 26
6. Connection Closure . . . . . . . . . . . . . . . . . . . . . 26 5.3.2. Priority Tree Maintenance . . . . . . . . . . . . . . 26
6.1. Idle Connections . . . . . . . . . . . . . . . . . . . . 26 5.4. Server Push . . . . . . . . . . . . . . . . . . . . . . . 27
6.2. Connection Shutdown . . . . . . . . . . . . . . . . . . . 27 6. Connection Closure . . . . . . . . . . . . . . . . . . . . . 28
6.3. Immediate Application Closure . . . . . . . . . . . . . . 28 6.1. Idle Connections . . . . . . . . . . . . . . . . . . . . 28
6.4. Transport Closure . . . . . . . . . . . . . . . . . . . . 28 6.2. Connection Shutdown . . . . . . . . . . . . . . . . . . . 29
7. Extensions to HTTP/QUIC . . . . . . . . . . . . . . . . . . . 29 6.3. Immediate Application Closure . . . . . . . . . . . . . . 30
8. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 29 6.4. Transport Closure . . . . . . . . . . . . . . . . . . . . 30
8.1. HTTP/QUIC Error Codes . . . . . . . . . . . . . . . . . . 30 7. Extensions to HTTP/3 . . . . . . . . . . . . . . . . . . . . 31
9. Security Considerations . . . . . . . . . . . . . . . . . . . 31 8. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 31
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32 8.1. HTTP/3 Error Codes . . . . . . . . . . . . . . . . . . . 32
10.1. Registration of HTTP/QUIC Identification String . . . . 32 9. Security Considerations . . . . . . . . . . . . . . . . . . . 33
10.2. Registration of QUIC Version Hint Alt-Svc Parameter . . 32 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 34
10.3. Frame Types . . . . . . . . . . . . . . . . . . . . . . 32 10.1. Registration of HTTP/3 Identification String . . . . . . 34
10.4. Settings Parameters . . . . . . . . . . . . . . . . . . 33 10.2. Registration of QUIC Version Hint Alt-Svc Parameter . . 34
10.5. Error Codes . . . . . . . . . . . . . . . . . . . . . . 34 10.3. Frame Types . . . . . . . . . . . . . . . . . . . . . . 34
10.6. Stream Types . . . . . . . . . . . . . . . . . . . . . . 37 10.4. Settings Parameters . . . . . . . . . . . . . . . . . . 36
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 38 10.5. Error Codes . . . . . . . . . . . . . . . . . . . . . . 37
11.1. Normative References . . . . . . . . . . . . . . . . . . 38 10.6. Stream Types . . . . . . . . . . . . . . . . . . . . . . 39
11.2. Informative References . . . . . . . . . . . . . . . . . 39 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 40
11.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 39 11.1. Normative References . . . . . . . . . . . . . . . . . . 40
Appendix A. Considerations for Transitioning from HTTP/2 . . . . 39 11.2. Informative References . . . . . . . . . . . . . . . . . 41
A.1. Streams . . . . . . . . . . . . . . . . . . . . . . . . . 40 11.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 42
A.2. HTTP Frame Types . . . . . . . . . . . . . . . . . . . . 40 Appendix A. Considerations for Transitioning from HTTP/2 . . . . 42
A.3. HTTP/2 SETTINGS Parameters . . . . . . . . . . . . . . . 42 A.1. Streams . . . . . . . . . . . . . . . . . . . . . . . . . 42
A.4. HTTP/2 Error Codes . . . . . . . . . . . . . . . . . . . 43 A.2. HTTP Frame Types . . . . . . . . . . . . . . . . . . . . 42
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 44 A.3. HTTP/2 SETTINGS Parameters . . . . . . . . . . . . . . . 44
B.1. Since draft-ietf-quic-http-15 . . . . . . . . . . . . . . 44 A.4. HTTP/2 Error Codes . . . . . . . . . . . . . . . . . . . 45
B.2. Since draft-ietf-quic-http-14 . . . . . . . . . . . . . . 44 Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 46
B.3. Since draft-ietf-quic-http-13 . . . . . . . . . . . . . . 44 B.1. Since draft-ietf-quic-http-16 . . . . . . . . . . . . . . 46
B.4. Since draft-ietf-quic-http-12 . . . . . . . . . . . . . . 45 B.2. Since draft-ietf-quic-http-15 . . . . . . . . . . . . . . 47
B.5. Since draft-ietf-quic-http-11 . . . . . . . . . . . . . . 45 B.3. Since draft-ietf-quic-http-14 . . . . . . . . . . . . . . 47
B.6. Since draft-ietf-quic-http-10 . . . . . . . . . . . . . . 45 B.4. Since draft-ietf-quic-http-13 . . . . . . . . . . . . . . 47
B.7. Since draft-ietf-quic-http-09 . . . . . . . . . . . . . . 45 B.5. Since draft-ietf-quic-http-12 . . . . . . . . . . . . . . 48
B.8. Since draft-ietf-quic-http-08 . . . . . . . . . . . . . . 46 B.6. Since draft-ietf-quic-http-11 . . . . . . . . . . . . . . 48
B.9. Since draft-ietf-quic-http-07 . . . . . . . . . . . . . . 46 B.7. Since draft-ietf-quic-http-10 . . . . . . . . . . . . . . 48
B.10. Since draft-ietf-quic-http-06 . . . . . . . . . . . . . . 46 B.8. Since draft-ietf-quic-http-09 . . . . . . . . . . . . . . 48
B.11. Since draft-ietf-quic-http-05 . . . . . . . . . . . . . . 46 B.9. Since draft-ietf-quic-http-08 . . . . . . . . . . . . . . 48
B.12. Since draft-ietf-quic-http-04 . . . . . . . . . . . . . . 46 B.10. Since draft-ietf-quic-http-07 . . . . . . . . . . . . . . 48
B.13. Since draft-ietf-quic-http-03 . . . . . . . . . . . . . . 47 B.11. Since draft-ietf-quic-http-06 . . . . . . . . . . . . . . 49
B.14. Since draft-ietf-quic-http-02 . . . . . . . . . . . . . . 47 B.12. Since draft-ietf-quic-http-05 . . . . . . . . . . . . . . 49
B.15. Since draft-ietf-quic-http-01 . . . . . . . . . . . . . . 47 B.13. Since draft-ietf-quic-http-04 . . . . . . . . . . . . . . 49
B.16. Since draft-ietf-quic-http-00 . . . . . . . . . . . . . . 47 B.14. Since draft-ietf-quic-http-03 . . . . . . . . . . . . . . 49
B.17. Since draft-shade-quic-http2-mapping-00 . . . . . . . . . 48 B.15. Since draft-ietf-quic-http-02 . . . . . . . . . . . . . . 49
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 48 B.16. Since draft-ietf-quic-http-01 . . . . . . . . . . . . . . 49
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 48 B.17. Since draft-ietf-quic-http-00 . . . . . . . . . . . . . . 50
B.18. Since draft-shade-quic-http2-mapping-00 . . . . . . . . . 50
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 50
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 51
1. Introduction 1. Introduction
HTTP semantics are used for a broad range of services on the HTTP semantics are used for a broad range of services on the
Internet. These semantics have commonly been used with two different Internet. These semantics have commonly been used with two different
TCP mappings, HTTP/1.1 and HTTP/2. HTTP/2 introduced a framing and TCP mappings, HTTP/1.1 and HTTP/2. HTTP/2 introduced a framing and
multiplexing layer to improve latency without modifying the transport multiplexing layer to improve latency without modifying the transport
layer. However, TCP's lack of visibility into parallel requests in layer. However, TCP's lack of visibility into parallel requests in
both mappings limited the possible performance gains. both mappings limited the possible performance gains.
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Field definitions are given in Augmented Backus-Naur Form (ABNF), as Field definitions are given in Augmented Backus-Naur Form (ABNF), as
defined in [RFC5234]. defined in [RFC5234].
This document uses the variable-length integer encoding from This document uses the variable-length integer encoding from
[QUIC-TRANSPORT]. [QUIC-TRANSPORT].
Protocol elements called "frames" exist in both this document and Protocol elements called "frames" exist in both this document and
[QUIC-TRANSPORT]. Where frames from [QUIC-TRANSPORT] are referenced, [QUIC-TRANSPORT]. Where frames from [QUIC-TRANSPORT] are referenced,
the frame name will be prefaced with "QUIC." For example, "QUIC the frame name will be prefaced with "QUIC." For example, "QUIC
APPLICATION_CLOSE frames." References without this preface refer to CONNECTION_CLOSE frames." References without this preface refer to
frames defined in Section 4.2. frames defined in Section 4.2.
2. Connection Setup and Management 2. Connection Setup and Management
2.1. Draft Version Identification 2.1. Draft Version Identification
*RFC Editor's Note:* Please remove this section prior to *RFC Editor's Note:* Please remove this section prior to
publication of a final version of this document. publication of a final version of this document.
HTTP/QUIC uses the token "hq" to identify itself in ALPN and Alt-Svc. HTTP/3 uses the token "h3" to identify itself in ALPN and Alt-Svc.
Only implementations of the final, published RFC can identify Only implementations of the final, published RFC can identify
themselves as "hq". Until such an RFC exists, implementations MUST themselves as "h3". Until such an RFC exists, implementations MUST
NOT identify themselves using this string. NOT identify themselves using this string.
Implementations of draft versions of the protocol MUST add the string Implementations of draft versions of the protocol MUST add the string
"-" and the corresponding draft number to the identifier. For "-" and the corresponding draft number to the identifier. For
example, draft-ietf-quic-http-01 is identified using the string "hq- example, draft-ietf-quic-http-01 is identified using the string
01". "h3-01".
Non-compatible experiments that are based on these draft versions Non-compatible experiments that are based on these draft versions
MUST append the string "-" and an experiment name to the identifier. MUST append the string "-" and an experiment name to the identifier.
For example, an experimental implementation based on draft-ietf-quic- For example, an experimental implementation based on draft-ietf-quic-
http-09 which reserves an extra stream for unsolicited transmission http-09 which reserves an extra stream for unsolicited transmission
of 1980s pop music might identify itself as "hq-09-rickroll". Note of 1980s pop music might identify itself as "h3-09-rickroll". Note
that any label MUST conform to the "token" syntax defined in that any label MUST conform to the "token" syntax defined in
Section 3.2.6 of [RFC7230]. Experimenters are encouraged to Section 3.2.6 of [RFC7230]. Experimenters are encouraged to
coordinate their experiments on the quic@ietf.org mailing list. coordinate their experiments on the quic@ietf.org mailing list.
2.2. Discovering an HTTP/QUIC Endpoint 2.2. Discovering an HTTP/3 Endpoint
An HTTP origin advertises the availability of an equivalent HTTP/QUIC An HTTP origin advertises the availability of an equivalent HTTP/3
endpoint via the Alt-Svc HTTP response header field or the HTTP/2 endpoint via the Alt-Svc HTTP response header field or the HTTP/2
ALTSVC frame ([ALTSVC]), using the ALPN token defined in Section 2.3. ALTSVC frame ([ALTSVC]), using the ALPN token defined in Section 2.3.
For example, an origin could indicate in an HTTP/1.1 or HTTP/2 For example, an origin could indicate in an HTTP/1.1 or HTTP/2
response that HTTP/QUIC was available on UDP port 50781 at the same response that HTTP/3 was available on UDP port 50781 at the same
hostname by including the following header field in any response: hostname by including the following header field in any response:
Alt-Svc: hq=":50781" Alt-Svc: h3=":50781"
On receipt of an Alt-Svc record indicating HTTP/QUIC support, a On receipt of an Alt-Svc record indicating HTTP/3 support, a client
client MAY attempt to establish a QUIC connection to the indicated MAY attempt to establish a QUIC connection to the indicated host and
host and port and, if successful, send HTTP requests using the port and, if successful, send HTTP requests using the mapping
mapping described in this document. described in this document.
Connectivity problems (e.g. firewall blocking UDP) can result in QUIC Connectivity problems (e.g. firewall blocking UDP) can result in QUIC
connection establishment failure, in which case the client SHOULD connection establishment failure, in which case the client SHOULD
continue using the existing connection or try another alternative continue using the existing connection or try another alternative
endpoint offered by the origin. endpoint offered by the origin.
Servers MAY serve HTTP/QUIC on any UDP port, since an alternative Servers MAY serve HTTP/3 on any UDP port, since an alternative always
always includes an explicit port. includes an explicit port.
2.2.1. QUIC Version Hints 2.2.1. QUIC Version Hints
This document defines the "quic" parameter for Alt-Svc, which MAY be This document defines the "quic" parameter for Alt-Svc, which MAY be
used to provide version-negotiation hints to HTTP/QUIC clients. QUIC used to provide version-negotiation hints to HTTP/3 clients. QUIC
versions are four-octet sequences with no additional constraints on versions are four-byte sequences with no additional constraints on
format. Leading zeros SHOULD be omitted for brevity. format. Leading zeros SHOULD be omitted for brevity.
Syntax: Syntax:
quic = DQUOTE version-number [ "," version-number ] * DQUOTE quic = DQUOTE version-number [ "," version-number ] * DQUOTE
version-number = 1*8HEXDIG; hex-encoded QUIC version version-number = 1*8HEXDIG; hex-encoded QUIC version
Where multiple versions are listed, the order of the values reflects Where multiple versions are listed, the order of the values reflects
the server's preference (with the first value being the most the server's preference (with the first value being the most
preferred version). Reserved versions MAY be listed, but unreserved preferred version). Reserved versions MAY be listed, but unreserved
versions which are not supported by the alternative SHOULD NOT be versions which are not supported by the alternative SHOULD NOT be
present in the list. Origins MAY omit supported versions for any present in the list. Origins MAY omit supported versions for any
reason. reason.
Clients MUST ignore any included versions which they do not support. Clients MUST ignore any included versions which they do not support.
The "quic" parameter MUST NOT occur more than once; clients SHOULD The "quic" parameter MUST NOT occur more than once; clients SHOULD
process only the first occurrence. process only the first occurrence.
For example, suppose a server supported both version 0x00000001 and For example, suppose a server supported both version 0x00000001 and
the version rendered in ASCII as "Q034". If it also opted to include the version rendered in ASCII as "Q034". If it also opted to include
the reserved version (from Section 3 of [QUIC-TRANSPORT]) 0x1abadaba, the reserved version (from Section 15 of [QUIC-TRANSPORT])
it could specify the following header field: 0x1abadaba, it could specify the following header field:
Alt-Svc: hq=":49288";quic="1,1abadaba,51303334" Alt-Svc: h3=":49288";quic="1,1abadaba,51303334"
A client acting on this header field would drop the reserved version A client acting on this header field would drop the reserved version
(not supported), then attempt to connect to the alternative using the (not supported), then attempt to connect to the alternative using the
first version in the list which it does support, if any. first version in the list which it does support, if any.
2.3. Connection Establishment 2.3. Connection Establishment
HTTP/QUIC relies on QUIC as the underlying transport. The QUIC HTTP/3 relies on QUIC as the underlying transport. The QUIC version
version being used MUST use TLS version 1.3 or greater as its being used MUST use TLS version 1.3 or greater as its handshake
handshake protocol. HTTP/QUIC clients MUST indicate the target protocol. HTTP/3 clients MUST indicate the target domain name during
domain name during the TLS handshake. This may be done using the the TLS handshake. This may be done using the Server Name Indication
Server Name Indication (SNI) [RFC6066] extension to TLS or using some (SNI) [RFC6066] extension to TLS or using some other mechanism.
other mechanism.
QUIC connections are established as described in [QUIC-TRANSPORT]. QUIC connections are established as described in [QUIC-TRANSPORT].
During connection establishment, HTTP/QUIC support is indicated by During connection establishment, HTTP/3 support is indicated by
selecting the ALPN token "hq" in the TLS handshake. Support for selecting the ALPN token "hq" in the TLS handshake. Support for
other application-layer protocols MAY be offered in the same other application-layer protocols MAY be offered in the same
handshake. handshake.
While connection-level options pertaining to the core QUIC protocol While connection-level options pertaining to the core QUIC protocol
are set in the initial crypto handshake, HTTP/QUIC-specific settings are set in the initial crypto handshake, HTTP/3-specific settings are
are conveyed in the SETTINGS frame. After the QUIC connection is conveyed in the SETTINGS frame. After the QUIC connection is
established, a SETTINGS frame (Section 4.2.5) MUST be sent by each established, a SETTINGS frame (Section 4.2.5) MUST be sent by each
endpoint as the initial frame of their respective HTTP control stream endpoint as the initial frame of their respective HTTP control stream
(see Section 3.2.1). The server MUST NOT process any request streams (see Section 3.2.1).
or send responses until the client's SETTINGS frame has been
received.
2.4. Connection Reuse 2.4. Connection Reuse
Once a connection exists to a server endpoint, this connection MAY be Once a connection exists to a server endpoint, this connection MAY be
reused for requests with multiple different URI authority components. reused for requests with multiple different URI authority components.
The client MAY send any requests for which the client considers the The client MAY send any requests for which the client considers the
server authoritative. server authoritative.
An authoritative HTTP/QUIC endpoint is typically discovered because An authoritative HTTP/3 endpoint is typically discovered because the
the client has received an Alt-Svc record from the request's origin client has received an Alt-Svc record from the request's origin which
which nominates the endpoint as a valid HTTP Alternative Service for nominates the endpoint as a valid HTTP Alternative Service for that
that origin. As required by [RFC7838], clients MUST check that the origin. As required by [RFC7838], clients MUST check that the
nominated server can present a valid certificate for the origin nominated server can present a valid certificate for the origin
before considering it authoritative. Clients MUST NOT assume that an before considering it authoritative. Clients MUST NOT assume that an
HTTP/QUIC endpoint is authoritative for other origins without an HTTP/3 endpoint is authoritative for other origins without an
explicit signal. explicit signal.
A server that does not wish clients to reuse connections for a A server that does not wish clients to reuse connections for a
particular origin can indicate that it is not authoritative for a particular origin can indicate that it is not authoritative for a
request by sending a 421 (Misdirected Request) status code in request by sending a 421 (Misdirected Request) status code in
response to the request (see Section 9.1.2 of [RFC7540]). response to the request (see Section 9.1.2 of [RFC7540]).
The considerations discussed in Section 9.1 of [RFC7540] also apply The considerations discussed in Section 9.1 of [RFC7540] also apply
to the management of HTTP/QUIC connections. to the management of HTTP/3 connections.
3. Stream Mapping and Usage 3. Stream Mapping and Usage
A QUIC stream provides reliable in-order delivery of bytes, but makes A QUIC stream provides reliable in-order delivery of bytes, but makes
no guarantees about order of delivery with regard to bytes on other no guarantees about order of delivery with regard to bytes on other
streams. On the wire, data is framed into QUIC STREAM frames, but streams. On the wire, data is framed into QUIC STREAM frames, but
this framing is invisible to the HTTP framing layer. The transport this framing is invisible to the HTTP framing layer. The transport
layer buffers and orders received QUIC STREAM frames, exposing the layer buffers and orders received QUIC STREAM frames, exposing the
data contained within as a reliable byte stream to the application. data contained within as a reliable byte stream to the application.
QUIC streams can be either unidirectional, carrying data only from QUIC streams can be either unidirectional, carrying data only from
initiator to receiver, or bidirectional. Streams can be initiated by initiator to receiver, or bidirectional. Streams can be initiated by
either the client or the server. For more detail on QUIC streams, either the client or the server. For more detail on QUIC streams,
see [QUIC-TRANSPORT], Section 9. see Section 2 of [QUIC-TRANSPORT].
When HTTP headers and data are sent over QUIC, the QUIC layer handles When HTTP headers and data are sent over QUIC, the QUIC layer handles
most of the stream management. HTTP does not need to do any separate most of the stream management. HTTP does not need to do any separate
multiplexing when using QUIC - data sent over a QUIC stream always multiplexing when using QUIC - data sent over a QUIC stream always
maps to a particular HTTP transaction or connection context. maps to a particular HTTP transaction or connection context.
3.1. Bidirectional Streams 3.1. Bidirectional Streams
All client-initiated bidirectional streams are used for HTTP requests All client-initiated bidirectional streams are used for HTTP requests
and responses. A bidirectional stream ensures that the response can and responses. A bidirectional stream ensures that the response can
be readily correlated with the request. This means that the client's be readily correlated with the request. This means that the client's
first request occurs on QUIC stream 0, with subsequent requests on first request occurs on QUIC stream 0, with subsequent requests on
stream 4, 8, and so on. In order to permit these streams to open, an stream 4, 8, and so on. In order to permit these streams to open, an
HTTP/QUIC client SHOULD send non-zero values for the QUIC transport HTTP/3 client SHOULD send non-zero values for the QUIC transport
parameters "initial_max_stream_data_bidi_local". An HTTP/QUIC server parameters "initial_max_stream_data_bidi_local". An HTTP/3 server
SHOULD send non-zero values for the QUIC transport parameters SHOULD send non-zero values for the QUIC transport parameters
"initial_max_stream_data_bidi_remote" and "initial_max_bidi_streams". "initial_max_stream_data_bidi_remote" and "initial_max_bidi_streams".
It is recommended that "initial_max_bidi_streams" be no smaller than It is recommended that "initial_max_bidi_streams" be no smaller than
100, so as to not unnecessarily limit parallelism. 100, so as to not unnecessarily limit parallelism.
These streams carry frames related to the request/response (see These streams carry frames related to the request/response (see
Section 5.1). When a stream terminates cleanly, if the last frame on Section 5.1). When a stream terminates cleanly, if the last frame on
the stream was truncated, this MUST be treated as a connection error the stream was truncated, this MUST be treated as a connection error
(see HTTP_MALFORMED_FRAME in Section 8.1). Streams which terminate (see HTTP_MALFORMED_FRAME in Section 8.1). Streams which terminate
abruptly may be reset at any point in the frame. abruptly may be reset at any point in the frame.
HTTP/QUIC does not use server-initiated bidirectional streams; HTTP/3 does not use server-initiated bidirectional streams; clients
clients MUST omit or specify a value of zero for the QUIC transport MUST omit or specify a value of zero for the QUIC transport parameter
parameter "initial_max_bidi_streams". "initial_max_bidi_streams".
3.2. Unidirectional Streams 3.2. Unidirectional Streams
Unidirectional streams, in either direction, are used for a range of Unidirectional streams, in either direction, are used for a range of
purposes. The purpose is indicated by a stream type, which is sent purposes. The purpose is indicated by a stream type, which is sent
as a single octet header at the start of the stream. The format and as a single byte header at the start of the stream. The format and
structure of data that follows this header is determined by the structure of data that follows this header is determined by the
stream type. stream type.
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|Stream Type (8)| |Stream Type (8)|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
Figure 1: Unidirectional Stream Header Figure 1: Unidirectional Stream Header
Some stream types are reserved (Section 3.2.3). Two stream types are Some stream types are reserved (Section 3.2.3). Two stream types are
defined in this document: control streams (Section 3.2.1) and push defined in this document: control streams (Section 3.2.1) and push
streams (Section 3.2.2). Other stream types can be defined by streams (Section 3.2.2). Other stream types can be defined by
extensions to HTTP/QUIC. extensions to HTTP/3; see Section 7 for more details.
Both clients and servers SHOULD send a value of three or greater for Both clients and servers SHOULD send a value of three or greater for
the QUIC transport parameter "initial_max_uni_streams". the QUIC transport parameter "initial_max_uni_streams".
If the stream header indicates a stream type which is not supported If the stream header indicates a stream type which is not supported
by the recipient, the remainder of the stream cannot be consumed as by the recipient, the remainder of the stream cannot be consumed as
the semantics are unknown. Recipients of unknown stream types MAY the semantics are unknown. Recipients of unknown stream types MAY
trigger a QUIC STOP_SENDING frame with an error code of trigger a QUIC STOP_SENDING frame with an error code of
HTTP_UNKNOWN_STREAM_TYPE, but MUST NOT consider such streams to be an HTTP_UNKNOWN_STREAM_TYPE, but MUST NOT consider such streams to be an
error of any kind. error of any kind.
Implementations MAY send stream types before knowing whether the peer Implementations MAY send stream types before knowing whether the peer
supports them. However, stream types which could modify the state or supports them. However, stream types which could modify the state or
semantics of existing protocol components, including QPACK or other semantics of existing protocol components, including QPACK or other
extensions, MUST NOT be sent until the peer is known to support them. extensions, MUST NOT be sent until the peer is known to support them.
3.2.1. Control Streams 3.2.1. Control Streams
The control stream is indicated by a stream type of "0x43" (ASCII A control stream is indicated by a stream type of "0x43" (ASCII 'C').
'C'). Data on this stream consists of HTTP/QUIC frames, as defined Data on this stream consists of HTTP/3 frames, as defined in
in Section 4.2. Section 4.2.
Each side MUST initiate a single control stream at the beginning of Each side MUST initiate a single control stream at the beginning of
the connection and send its SETTINGS frame as the first frame on this the connection and send its SETTINGS frame as the first frame on this
stream. If the first frame of the control stream is any other frame stream. If the first frame of the control stream is any other frame
type, this MUST be treated as a connection error of type type, this MUST be treated as a connection error of type
HTTP_MISSING_SETTINGS. Only one control stream per peer is HTTP_MISSING_SETTINGS. Only one control stream per peer is
permitted; receipt of a second stream which claims to be a control permitted; receipt of a second stream which claims to be a control
stream MUST be treated as a connection error of type stream MUST be treated as a connection error of type
HTTP_WRONG_STREAM_COUNT. If the control stream is closed at any HTTP_WRONG_STREAM_COUNT. If the control stream is closed at any
point, this MUST be treated as a connection error of type point, this MUST be treated as a connection error of type
skipping to change at page 10, line 4 skipping to change at page 10, line 4
bidirectional stream. This allows either peer to send data as soon bidirectional stream. This allows either peer to send data as soon
they are able. Depending on whether 0-RTT is enabled on the they are able. Depending on whether 0-RTT is enabled on the
connection, either client or server might be able to send stream data connection, either client or server might be able to send stream data
first after the cryptographic handshake completes. first after the cryptographic handshake completes.
3.2.2. Push Streams 3.2.2. Push Streams
A push stream is indicated by a stream type of "0x50" (ASCII 'P'), A push stream is indicated by a stream type of "0x50" (ASCII 'P'),
followed by the Push ID of the promise that it fulfills, encoded as a followed by the Push ID of the promise that it fulfills, encoded as a
variable-length integer. The remaining data on this stream consists variable-length integer. The remaining data on this stream consists
of HTTP/QUIC frames, as defined in Section 4.2, and fulfills a of HTTP/3 frames, as defined in Section 4.2, and fulfills a promised
promised server push. Server push and Push IDs are described in server push. Server push and Push IDs are described in Section 5.4.
Section 5.4.
Only servers can push; if a server receives a client-initiated push Only servers can push; if a server receives a client-initiated push
stream, this MUST be treated as a stream error of type stream, this MUST be treated as a stream error of type
HTTP_WRONG_STREAM_DIRECTION. HTTP_WRONG_STREAM_DIRECTION.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Stream Type (8)| Push ID (i) ... |Stream Type (8)| Push ID (i) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 10, line 39 skipping to change at page 10, line 38
semantic meaning, and can be sent when application-layer padding is semantic meaning, and can be sent when application-layer padding is
desired. They MAY also be sent on connections where no request data desired. They MAY also be sent on connections where no request data
is currently being transferred. Endpoints MUST NOT consider these is currently being transferred. Endpoints MUST NOT consider these
streams to have any meaning upon receipt. streams to have any meaning upon receipt.
The payload and length of the stream are selected in any manner the The payload and length of the stream are selected in any manner the
implementation chooses. implementation chooses.
4. HTTP Framing Layer 4. HTTP Framing Layer
Frames are used on the control stream, request streams, and push Frames are used on control streams, request streams, and push
streams. This section describes HTTP framing in QUIC. For a streams. This section describes HTTP framing in QUIC. For a
comparison with HTTP/2 frames, see Appendix A.2. comparison with HTTP/2 frames, see Appendix A.2.
4.1. Frame Layout 4.1. Frame Layout
All frames have the following format: All frames have the following format:
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length (i) ... | Length (i) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (8) | Frame Payload (*) ... | Type (8) | Frame Payload (*) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: HTTP/QUIC frame format Figure 3: HTTP/3 frame format
A frame includes the following fields: A frame includes the following fields:
Length: A variable-length integer that describes the length of the Length: A variable-length integer that describes the length of the
Frame Payload. This length does not include the Type field. Frame Payload. This length does not include the Type field.
Type: An 8-bit type for the frame. Type: An 8-bit type for the frame.
Frame Payload: A payload, the semantics of which are determined by Frame Payload: A payload, the semantics of which are determined by
the Type field. the Type field.
Each frame's payload MUST contain exactly the identified fields. A Each frame's payload MUST contain exactly the identified fields. A
frame that contains additional octets after the identified fields or frame that contains additional bytes after the identified fields or a
a frame that terminates before the end of the identified fields MUST frame that terminates before the end of the identified fields MUST be
be treated as a connection error of type HTTP_MALFORMED_FRAME. treated as a connection error of type HTTP_MALFORMED_FRAME.
4.2. Frame Definitions 4.2. Frame Definitions
4.2.1. DATA 4.2.1. DATA
DATA frames (type=0x0) convey arbitrary, variable-length sequences of DATA frames (type=0x0) convey arbitrary, variable-length sequences of
octets associated with an HTTP request or response payload. bytes associated with an HTTP request or response payload.
DATA frames MUST be associated with an HTTP request or response. If DATA frames MUST be associated with an HTTP request or response. If
a DATA frame is received on either control stream, the recipient MUST a DATA frame is received on either control stream, the recipient MUST
respond with a connection error (Section 8) of type respond with a connection error (Section 8) of type
HTTP_WRONG_STREAM. HTTP_WRONG_STREAM.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload (*) ... | Payload (*) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: DATA frame payload Figure 4: DATA frame payload
DATA frames MUST contain a non-zero-length payload. If a DATA frame
is received with a payload length of zero, the recipient MUST respond
with a stream error (Section 8) of type HTTP_MALFORMED_FRAME.
4.2.2. HEADERS 4.2.2. HEADERS
The HEADERS frame (type=0x1) is used to carry a header block, The HEADERS frame (type=0x1) is used to carry a header block,
compressed using QPACK. See [QPACK] for more details. compressed using QPACK. See [QPACK] for more details.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Header Block (*) ... | Header Block (*) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: HEADERS frame payload Figure 5: HEADERS frame payload
HEADERS frames can only be sent on request / push streams. HEADERS frames can only be sent on request / push streams.
4.2.3. PRIORITY 4.2.3. PRIORITY
The PRIORITY (type=0x02) frame specifies the sender-advised priority The PRIORITY (type=0x02) frame specifies the client-advised priority
of a stream. In order to ensure that prioritization is processed in of a stream.
a consistent order, PRIORITY frames MUST be sent on the control
stream. A PRIORITY frame sent on any other stream MUST be treated as When opening a new request stream, a PRIORITY frame MAY be sent as
a connection error of type HTTP_WRONG_STREAM. the first frame of the stream creating a dependency on an existing
element. In order to ensure that prioritization is processed in a
consistent order, any subsequent PRIORITY frames MUST be sent on the
control stream. A PRIORITY frame received after other frames on a
request stream MUST be treated as a stream error of type
HTTP_UNEXPECTED_FRAME.
If, by the time a new request stream is opened, its priority
information has already been received via the control stream, the
PRIORITY frame sent on the request stream MUST be ignored.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|PT |DT |Empty|E| Prioritized Element ID (i) ... |PT |DT | Empty | [Prioritized Element ID (i)] ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Element Dependency ID (i) ... | [Element Dependency ID (i)] ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Weight (8) | | Weight (8) |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
Figure 6: PRIORITY frame payload Figure 6: PRIORITY frame payload
The PRIORITY frame payload has the following fields: The PRIORITY frame payload has the following fields:
Prioritized Type: A two-bit field indicating the type of element Prioritized Type: A two-bit field indicating the type of element
being prioritized. being prioritized. When sent on a request stream, this MUST be
set to "11". When sent on the control stream, this MUST NOT be
set to "11".
Dependency Type: A two-bit field indicating the type of element Dependency Type: A two-bit field indicating the type of element
being depended on. being depended on.
Empty: A three-bit field which MUST be zero when sent and MUST be Empty: A four-bit field which MUST be zero when sent and MUST be
ignored on receipt. ignored on receipt.
Exclusive: A flag which indicates that the stream dependency is
exclusive (see [RFC7540], Section 5.3).
Prioritized Element ID: A variable-length integer that identifies Prioritized Element ID: A variable-length integer that identifies
the element being prioritized. Depending on the value of the element being prioritized. Depending on the value of
Prioritized Type, this contains the Stream ID of a request stream, Prioritized Type, this contains the Stream ID of a request stream,
the Push ID of a promised resource, or a Placeholder ID of a the Push ID of a promised resource, a Placeholder ID of a
placeholder. placeholder, or is absent.
Element Dependency ID: A variable-length integer that identifies the Element Dependency ID: A variable-length integer that identifies the
element on which a dependency is being expressed. Depending on element on which a dependency is being expressed. Depending on
the value of Dependency Type, this contains the Stream ID of a the value of Dependency Type, this contains the Stream ID of a
request stream, the Push ID of a promised resource, the request stream, the Push ID of a promised resource, the
Placeholder ID of a placeholder, or is ignored. For details of Placeholder ID of a placeholder, or is absent. For details of
dependencies, see Section 5.3 and [RFC7540], Section 5.3. dependencies, see Section 5.3 and [RFC7540], Section 5.3.
Weight: An unsigned 8-bit integer representing a priority weight for Weight: An unsigned 8-bit integer representing a priority weight for
the stream (see [RFC7540], Section 5.3). Add one to the value to the prioritized element (see [RFC7540], Section 5.3). Add one to
obtain a weight between 1 and 256. the value to obtain a weight between 1 and 256.
A PRIORITY frame identifies an element to prioritize, and an element A PRIORITY frame identifies an element to prioritize, and an element
upon which it depends. A Prioritized ID or Dependency ID identifies upon which it depends. A Prioritized ID or Dependency ID identifies
a client-initiated request using the corresponding stream ID, a a client-initiated request using the corresponding stream ID, a
server push using a Push ID (see Section 4.2.6), or a placeholder server push using a Push ID (see Section 4.2.6), or a placeholder
using a Placeholder ID (see Section 5.3.1). using a Placeholder ID (see Section 5.3.1).
The values for the Prioritized Element Type and Element Dependency The values for the Prioritized Element Type and Element Dependency
Type imply the interpretation of the associated Element ID fields. Type imply the interpretation of the associated Element ID fields.
+-----------+------------------+---------------------+ +-----------+------------------+---------------------------------+
| Type Bits | Type Description | Element ID Contents | | Type Bits | Type Description | Prioritized Element ID Contents |
+-----------+------------------+---------------------+ +-----------+------------------+---------------------------------+
| 00 | Request stream | Stream ID | | 00 | Request stream | Stream ID |
| | | | | | | |
| 01 | Push stream | Push ID | | 01 | Push stream | Push ID |
| | | | | | | |
| 10 | Placeholder | Placeholder ID | | 10 | Placeholder | Placeholder ID |
| | | | | | | |
| 11 | Root of the tree | Ignored | | 11 | Current stream | Absent |
+-----------+------------------+---------------------+ +-----------+------------------+---------------------------------+
+-----------+------------------+--------------------------------+
| Type Bits | Type Description | Element Dependency ID Contents |
+-----------+------------------+--------------------------------+
| 00 | Request stream | Stream ID |
| | | |
| 01 | Push stream | Push ID |
| | | |
| 10 | Placeholder | Placeholder ID |
| | | |
| 11 | Root of the tree | Absent |
+-----------+------------------+--------------------------------+
Note that the root of the tree cannot be referenced using a Stream ID Note that the root of the tree cannot be referenced using a Stream ID
of 0, as in [RFC7540]; QUIC stream 0 carries a valid HTTP request. of 0, as in [RFC7540]; QUIC stream 0 carries a valid HTTP request.
The root of the tree cannot be reprioritized. A PRIORITY frame that The root of the tree cannot be reprioritized. A PRIORITY frame sent
prioritizes the root of the tree MUST be treated as a connection on a request stream with the Prioritized Element Type set to any
error of type HTTP_MALFORMED_FRAME. value other than "11" or which expresses a dependency on a request
with a greater Stream ID than the current stream MUST be treated as a
stream error of type HTTP_MALFORMED_FRAME. Likewise, a PRIORITY
frame sent on a control stream with the Prioritized Element Type set
to "11" MUST be treated as a connection error of type
HTTP_MALFORMED_FRAME.
When a PRIORITY frame claims to reference a request, the associated When a PRIORITY frame claims to reference a request, the associated
ID MUST identify a client-initiated bidirectional stream. A server ID MUST identify a client-initiated bidirectional stream. A server
MUST treat receipt of PRIORITY frame with a Stream ID of any other MUST treat receipt of PRIORITY frame with a Stream ID of any other
type as a connection error of type HTTP_MALFORMED_FRAME. type as a connection error of type HTTP_MALFORMED_FRAME.
A PRIORITY frame that references a non-existent Push ID or a A PRIORITY frame that references a non-existent Push ID or a
Placeholder ID greater than the server's limit MUST be treated as a Placeholder ID greater than the server's limit MUST be treated as an
HTTP_MALFORMED_FRAME error. HTTP_MALFORMED_FRAME error.
A PRIORITY frame received on any stream other than a request or
control stream MUST be treated as a connection error of type
HTTP_WRONG_STREAM.
PRIORITY frames received by a client MUST be treated as a stream
error of type HTTP_UNEXPECTED_FRAME.
4.2.4. CANCEL_PUSH 4.2.4. CANCEL_PUSH
The CANCEL_PUSH frame (type=0x3) is used to request cancellation of a The CANCEL_PUSH frame (type=0x3) is used to request cancellation of a
server push prior to the push stream being created. The CANCEL_PUSH server push prior to the push stream being created. The CANCEL_PUSH
frame identifies a server push by Push ID (see Section 4.2.6), frame identifies a server push by Push ID (see Section 4.2.6),
encoded as a variable-length integer. encoded as a variable-length integer.
When a server receives this frame, it aborts sending the response for When a server receives this frame, it aborts sending the response for
the identified server push. If the server has not yet started to the identified server push. If the server has not yet started to
send the server push, it can use the receipt of a CANCEL_PUSH frame send the server push, it can use the receipt of a CANCEL_PUSH frame
to avoid opening a push stream. If the push stream has been opened to avoid opening a push stream. If the push stream has been opened
by the server, the server SHOULD send a QUIC RST_STREAM frame on that by the server, the server SHOULD send a QUIC RESET_STREAM frame on
stream and cease transmission of the response. that stream and cease transmission of the response.
A server can send this frame to indicate that it will not be A server can send this frame to indicate that it will not be
fulfilling a promise prior to creation of a push stream. Once the fulfilling a promise prior to creation of a push stream. Once the
push stream has been created, sending CANCEL_PUSH has no effect on push stream has been created, sending CANCEL_PUSH has no effect on
the state of the push stream. A QUIC RST_STREAM frame SHOULD be used the state of the push stream. A QUIC RESET_STREAM frame SHOULD be
instead to abort transmission of the server push response. used instead to abort transmission of the server push response.
A CANCEL_PUSH frame is sent on the control stream. Sending a A CANCEL_PUSH frame is sent on the control stream. Sending a
CANCEL_PUSH frame on a stream other than the control stream MUST be CANCEL_PUSH frame on a stream other than the control stream MUST be
treated as a stream error of type HTTP_WRONG_STREAM. treated as a stream error of type HTTP_WRONG_STREAM.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Push ID (i) ... | Push ID (i) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 15, line 16 skipping to change at page 15, line 49
The SETTINGS frame (type=0x4) conveys configuration parameters that The SETTINGS frame (type=0x4) conveys configuration parameters that
affect how endpoints communicate, such as preferences and constraints affect how endpoints communicate, such as preferences and constraints
on peer behavior. Individually, a SETTINGS parameter can also be on peer behavior. Individually, a SETTINGS parameter can also be
referred to as a "setting"; the identifier and value of each setting referred to as a "setting"; the identifier and value of each setting
parameter can be referred to as a "setting identifier" and a "setting parameter can be referred to as a "setting identifier" and a "setting
value". value".
SETTINGS parameters are not negotiated; they describe characteristics SETTINGS parameters are not negotiated; they describe characteristics
of the sending peer, which can be used by the receiving peer. of the sending peer, which can be used by the receiving peer.
However, a negotiation can be implied by the use of SETTINGS - a peer However, a negotiation can be implied by the use of SETTINGS - each
uses SETTINGS to advertise a set of supported values. The recipient peer uses SETTINGS to advertise a set of supported values. The
can then choose which entries from this list are also acceptable and definition of the setting would describe how each peer combines the
proceed with the value it has chosen. (This choice could be two sets to conclude which choice will be used. SETTINGS does not
announced in a field of an extension frame, or in its own value in provide a mechanism to identify when the choice takes effect.
SETTINGS.)
Different values for the same parameter can be advertised by each Different values for the same parameter can be advertised by each
peer. For example, a client might be willing to consume a very large peer. For example, a client might be willing to consume a very large
response header, while servers are more cautious about request size. response header, while servers are more cautious about request size.
Parameters MUST NOT occur more than once. A receiver MAY treat the Parameters MUST NOT occur more than once. A receiver MAY treat the
presence of the same parameter more than once as a connection error presence of the same parameter more than once as a connection error
of type HTTP_MALFORMED_FRAME. of type HTTP_MALFORMED_FRAME.
The payload of a SETTINGS frame consists of zero or more parameters, The payload of a SETTINGS frame consists of zero or more parameters,
skipping to change at page 16, line 12 skipping to change at page 16, line 43
An implementation MUST ignore the contents for any SETTINGS An implementation MUST ignore the contents for any SETTINGS
identifier it does not understand. identifier it does not understand.
SETTINGS frames always apply to a connection, never a single stream. SETTINGS frames always apply to a connection, never a single stream.
A SETTINGS frame MUST be sent as the first frame of each control A SETTINGS frame MUST be sent as the first frame of each control
stream (see Section 3.2.1) by each peer, and MUST NOT be sent stream (see Section 3.2.1) by each peer, and MUST NOT be sent
subsequently or on any other stream. If an endpoint receives a subsequently or on any other stream. If an endpoint receives a
SETTINGS frame on a different stream, the endpoint MUST respond with SETTINGS frame on a different stream, the endpoint MUST respond with
a connection error of type HTTP_WRONG_STREAM. If an endpoint a connection error of type HTTP_WRONG_STREAM. If an endpoint
receives a second SETTINGS frame, the endpoint MUST respond with a receives a second SETTINGS frame, the endpoint MUST respond with a
connection error of type HTTP_MALFORMED_FRAME. connection error of type HTTP_UNEXPECTED_FRAME.
The SETTINGS frame affects connection state. A badly formed or The SETTINGS frame affects connection state. A badly formed or
incomplete SETTINGS frame MUST be treated as a connection error incomplete SETTINGS frame MUST be treated as a connection error
(Section 8) of type HTTP_MALFORMED_FRAME. (Section 8) of type HTTP_MALFORMED_FRAME.
4.2.5.1. Defined SETTINGS Parameters 4.2.5.1. Defined SETTINGS Parameters
The following settings are defined in HTTP/QUIC: The following settings are defined in HTTP/3:
SETTINGS_NUM_PLACEHOLDERS (0x3): This value SHOULD be non-zero. The
default value is 16.
SETTINGS_MAX_HEADER_LIST_SIZE (0x6): The default value is unlimited. SETTINGS_MAX_HEADER_LIST_SIZE (0x6): The default value is unlimited.
See Section 5.1.1 for usage.
SETTINGS_NUM_PLACEHOLDERS (0x8): The default value is 0. However,
this value SHOULD be set to a non-zero value by servers. See
Section 5.3.1 for usage.
Setting identifiers of the format "0x?a?a" are reserved to exercise Setting identifiers of the format "0x?a?a" are reserved to exercise
the requirement that unknown identifiers be ignored. Such settings the requirement that unknown identifiers be ignored. Such settings
have no defined meaning. Endpoints SHOULD include at least one such have no defined meaning. Endpoints SHOULD include at least one such
setting in their SETTINGS frame. Endpoints MUST NOT consider such setting in their SETTINGS frame. Endpoints MUST NOT consider such
settings to have any meaning upon receipt. settings to have any meaning upon receipt.
Because the setting has no defined meaning, the value of the setting Because the setting has no defined meaning, the value of the setting
can be any value the implementation selects. can be any value the implementation selects.
Additional settings MAY be defined by extensions to HTTP/QUIC. Additional settings can be defined by extensions to HTTP/3; see
Section 7 for more details.
4.2.5.2. Initialization 4.2.5.2. Initialization
When a 0-RTT QUIC connection is being used, the client's initial An HTTP implementation MUST NOT send frames or requests which would
requests will be sent before the arrival of the server's SETTINGS be invalid based on its current understanding of the peer's settings.
frame. Clients MUST store the settings the server provided in the All settings begin at an initial value, and are updated upon receipt
session being resumed and MUST comply with stored settings until the of a SETTINGS frame. For servers, the initial value of each client
server's current settings are received. Remembered settings apply to setting is the default value.
the new connection until the server's SETTINGS frame is received.
For clients using a 1-RTT QUIC connection, the initial value of each
server setting is the default value. When a 0-RTT QUIC connection is
being used, the initial value of each server setting is the value
used in the previous session. Clients MUST store the settings the
server provided in the session being resumed and MUST comply with
stored settings until the current server settings are received.
A server can remember the settings that it advertised, or store an A server can remember the settings that it advertised, or store an
integrity-protected copy of the values in the ticket and recover the integrity-protected copy of the values in the ticket and recover the
information when accepting 0-RTT data. A server uses the HTTP/QUIC information when accepting 0-RTT data. A server uses the HTTP/3
settings values in determining whether to accept 0-RTT data. settings values in determining whether to accept 0-RTT data.
A server MAY accept 0-RTT and subsequently provide different settings A server MAY accept 0-RTT and subsequently provide different settings
in its SETTINGS frame. If 0-RTT data is accepted by the server, its in its SETTINGS frame. If 0-RTT data is accepted by the server, its
SETTINGS frame MUST NOT reduce any limits or alter any values that SETTINGS frame MUST NOT reduce any limits or alter any values that
might be violated by the client with its 0-RTT data. might be violated by the client with its 0-RTT data.
When a 1-RTT QUIC connection is being used, the client MUST NOT send
requests prior to receiving and processing the server's SETTINGS
frame.
4.2.6. PUSH_PROMISE 4.2.6. PUSH_PROMISE
The PUSH_PROMISE frame (type=0x05) is used to carry a promised The PUSH_PROMISE frame (type=0x05) is used to carry a promised
request header set from server to client, as in HTTP/2. request header set from server to client, as in HTTP/2.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Push ID (i) ... | Push ID (i) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Header Block (*) ... | Header Block (*) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 9: PUSH_PROMISE frame payload Figure 9: PUSH_PROMISE frame payload
The payload consists of: The payload consists of:
Push ID: A variable-length integer that identifies the server push Push ID: A variable-length integer that identifies the server push
operation. A Push ID is used in push stream headers operation. A Push ID is used in push stream headers
(Section 5.4), CANCEL_PUSH frames (Section 4.2.4), and PRIORITY (Section 5.4), CANCEL_PUSH frames (Section 4.2.4), DUPLICATE_PUSH
frames (Section 4.2.3). frames (Section 4.2.9), and PRIORITY frames (Section 4.2.3).
Header Block: QPACK-compressed request header fields for the Header Block: QPACK-compressed request header fields for the
promised response. See [QPACK] for more details. promised response. See [QPACK] for more details.
A server MUST NOT use a Push ID that is larger than the client has A server MUST NOT use a Push ID that is larger than the client has
provided in a MAX_PUSH_ID frame (Section 4.2.8). A client MUST treat provided in a MAX_PUSH_ID frame (Section 4.2.8) and MUST NOT use the
same Push ID in multiple PUSH_PROMISE frames. A client MUST treat
receipt of a PUSH_PROMISE that contains a larger Push ID than the receipt of a PUSH_PROMISE that contains a larger Push ID than the
client has advertised as a connection error of type client has advertised or a Push ID which has already been promised as
HTTP_MALFORMED_FRAME. a connection error of type HTTP_MALFORMED_FRAME.
A server MAY use the same Push ID in multiple PUSH_PROMISE frames.
This allows the server to use the same server push in response to
multiple concurrent requests. Referencing the same server push
ensures that a PUSH_PROMISE can be made in relation to every response
in which server push might be needed without duplicating pushes.
A server that uses the same Push ID in multiple PUSH_PROMISE frames
MUST include the same header fields each time. The octets of the
header block MAY be different due to differing encoding, but the
header fields and their values MUST be identical. Note that ordering
of header fields is significant. A client MUST treat receipt of a
PUSH_PROMISE with conflicting header field values for the same Push
ID as a connection error of type HTTP_MALFORMED_FRAME.
Allowing duplicate references to the same Push ID is primarily to See Section 5.4 for a description of the overall server push
reduce duplication caused by concurrent requests. A server SHOULD mechanism.
avoid reusing a Push ID over a long period. Clients are likely to
consume server push responses and not retain them for reuse over
time. Clients that see a PUSH_PROMISE that uses a Push ID that they
have since consumed and discarded are forced to ignore the
PUSH_PROMISE.
4.2.7. GOAWAY 4.2.7. GOAWAY
The GOAWAY frame (type=0x7) is used to initiate graceful shutdown of The GOAWAY frame (type=0x7) is used to initiate graceful shutdown of
a connection by a server. GOAWAY allows a server to stop accepting a connection by a server. GOAWAY allows a server to stop accepting
new requests while still finishing processing of previously received new requests while still finishing processing of previously received
requests. This enables administrative actions, like server requests. This enables administrative actions, like server
maintenance. GOAWAY by itself does not close a connection. maintenance. GOAWAY by itself does not close a connection.
0 1 2 3 0 1 2 3
skipping to change at page 18, line 41 skipping to change at page 19, line 20
Figure 10: GOAWAY frame payload Figure 10: GOAWAY frame payload
The GOAWAY frame carries a QUIC Stream ID for a client-initiated The GOAWAY frame carries a QUIC Stream ID for a client-initiated
bidirectional stream encoded as a variable-length integer. A client bidirectional stream encoded as a variable-length integer. A client
MUST treat receipt of a GOAWAY frame containing a Stream ID of any MUST treat receipt of a GOAWAY frame containing a Stream ID of any
other type as a connection error of type HTTP_MALFORMED_FRAME. other type as a connection error of type HTTP_MALFORMED_FRAME.
Clients do not need to send GOAWAY to initiate a graceful shutdown; Clients do not need to send GOAWAY to initiate a graceful shutdown;
they simply stop making new requests. A server MUST treat receipt of they simply stop making new requests. A server MUST treat receipt of
a GOAWAY frame as a connection error (Section 8) of type a GOAWAY frame on any stream as a connection error (Section 8) of
HTTP_UNEXPECTED_GOAWAY. type HTTP_UNEXPECTED_FRAME.
The GOAWAY frame applies to the connection, not a specific stream. The GOAWAY frame applies to the connection, not a specific stream. A
An endpoint MUST treat a GOAWAY frame on a stream other than the client MUST treat a GOAWAY frame on a stream other than the control
control stream as a connection error (Section 8) of type stream as a connection error (Section 8) of type
HTTP_WRONG_STREAM. HTTP_UNEXPECTED_FRAME.
See Section 6.2 for more information on the use of the GOAWAY frame. See Section 6.2 for more information on the use of the GOAWAY frame.
4.2.8. MAX_PUSH_ID 4.2.8. MAX_PUSH_ID
The MAX_PUSH_ID frame (type=0xD) is used by clients to control the The MAX_PUSH_ID frame (type=0xD) is used by clients to control the
number of server pushes that the server can initiate. This sets the number of server pushes that the server can initiate. This sets the
maximum value for a Push ID that the server can use in a PUSH_PROMISE maximum value for a Push ID that the server can use in a PUSH_PROMISE
frame. Consequently, this also limits the number of push streams frame. Consequently, this also limits the number of push streams
that the server can initiate in addition to the limit set by the QUIC that the server can initiate in addition to the limit set by the QUIC
skipping to change at page 19, line 47 skipping to change at page 20, line 24
identifies the maximum value for a Push ID that the server can use identifies the maximum value for a Push ID that the server can use
(see Section 4.2.6). A MAX_PUSH_ID frame cannot reduce the maximum (see Section 4.2.6). A MAX_PUSH_ID frame cannot reduce the maximum
Push ID; receipt of a MAX_PUSH_ID that contains a smaller value than Push ID; receipt of a MAX_PUSH_ID that contains a smaller value than
previously received MUST be treated as a connection error of type previously received MUST be treated as a connection error of type
HTTP_MALFORMED_FRAME. HTTP_MALFORMED_FRAME.
A server MUST treat a MAX_PUSH_ID frame payload that does not contain A server MUST treat a MAX_PUSH_ID frame payload that does not contain
a single variable-length integer as a connection error of type a single variable-length integer as a connection error of type
HTTP_MALFORMED_FRAME. HTTP_MALFORMED_FRAME.
4.2.9. Reserved Frame Types 4.2.9. DUPLICATE_PUSH
The DUPLICATE_PUSH frame (type=0xE) is used by servers to indicate
that an existing pushed resource is related to multiple client
requests.
The DUPLICATE_PUSH frame is always sent on a request stream. Receipt
of a DUPLICATE_PUSH frame on any other stream MUST be treated as a
connection error of type HTTP_WRONG_STREAM.
A client MUST NOT send a DUPLICATE_PUSH frame. A server MUST treat
the receipt of a DUPLICATE_PUSH frame as a connection error of type
HTTP_MALFORMED_FRAME.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Push ID (i) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 12: DUPLICATE_PUSH frame payload
The DUPLICATE_PUSH frame carries a single variable-length integer
that identifies the Push ID of a resource that the server has
previously promised (see Section 4.2.6). A server MUST treat a
DUPLICATE_PUSH frame payload that does not contain a single variable-
length integer as a connection error of type HTTP_MALFORMED_FRAME.
This frame allows the server to use the same server push in response
to multiple concurrent requests. Referencing the same server push
ensures that a promise can be made in relation to every response in
which server push might be needed without duplicating request headers
or pushed responses.
Allowing duplicate references to the same Push ID is primarily to
reduce duplication caused by concurrent requests. A server SHOULD
avoid reusing a Push ID over a long period. Clients are likely to
consume server push responses and not retain them for reuse over
time. Clients that see a DUPLICATE_PUSH that uses a Push ID that
they have since consumed and discarded are forced to ignore the
DUPLICATE_PUSH.
4.2.10. Reserved Frame Types
Frame types of the format "0xb + (0x1f * N)" are reserved to exercise Frame types of the format "0xb + (0x1f * N)" are reserved to exercise
the requirement that unknown types be ignored (Section 7). These the requirement that unknown types be ignored (Section 7). These
frames have no semantic value, and can be sent when application-layer frames have no semantic value, and can be sent when application-layer
padding is desired. They MAY also be sent on connections where no padding is desired. They MAY also be sent on connections where no
request data is currently being transferred. Endpoints MUST NOT request data is currently being transferred. Endpoints MUST NOT
consider these frames to have any meaning upon receipt. consider these frames to have any meaning upon receipt.
The payload and length of the frames are selected in any manner the The payload and length of the frames are selected in any manner the
implementation chooses. implementation chooses.
skipping to change at page 20, line 37 skipping to change at page 22, line 10
present (see [RFC7230], Section 4.1.2). present (see [RFC7230], Section 4.1.2).
A server MAY interleave one or more PUSH_PROMISE frames (see A server MAY interleave one or more PUSH_PROMISE frames (see
Section 4.2.6) with the frames of a response message. These Section 4.2.6) with the frames of a response message. These
PUSH_PROMISE frames are not part of the response; see Section 5.4 for PUSH_PROMISE frames are not part of the response; see Section 5.4 for
more details. more details.
The "chunked" transfer encoding defined in Section 4.1 of [RFC7230] The "chunked" transfer encoding defined in Section 4.1 of [RFC7230]
MUST NOT be used. MUST NOT be used.
Trailing header fields are carried in an additional header block Trailing header fields are carried in an additional HEADERS frame
following the body. Senders MUST send only one header block in the following the body. Senders MUST send only one HEADERS frame in the
trailers section; receivers MUST discard any subsequent header trailers section; receivers MUST discard any subsequent HEADERS
blocks. frames.
A response MAY consist of multiple messages when and only when one or A response MAY consist of multiple messages when and only when one or
more informational responses (1xx, see [RFC7231], Section 6.2) more informational responses (1xx, see [RFC7231], Section 6.2)
precede a final response to the same request. Non-final responses do precede a final response to the same request. Non-final responses do
not contain a payload body or trailers. not contain a payload body or trailers.
An HTTP request/response exchange fully consumes a bidirectional QUIC An HTTP request/response exchange fully consumes a bidirectional QUIC
stream. After sending a request, a client closes the stream for stream. After sending a request, a client MUST close the stream for
sending; after sending a final response, the server closes the stream sending. Unless using the CONNECT method (see Section 5.2), clients
for sending and the QUIC stream is fully closed. Requests and MUST NOT make stream closure dependent on receiving a response to
responses are considered complete when the corresponding QUIC stream their request. After sending a final response, the server MUST close
is closed in the appropriate direction. the stream for sending. At this point, the QUIC stream is fully
closed.
When a stream is closed, this indicates the end of an HTTP message.
Because some messages are large or unbounded, endpoints SHOULD begin
processing partial HTTP messages once enough of the message has been
received to make progress. If a client stream terminates without
enough of the HTTP message to provide a complete response, the server
SHOULD abort its response with the error code
HTTP_INCOMPLETE_REQUEST.
A server can send a complete response prior to the client sending an A server can send a complete response prior to the client sending an
entire request if the response does not depend on any portion of the entire request if the response does not depend on any portion of the
request that has not been sent and received. When this is true, a request that has not been sent and received. When this is true, a
server MAY request that the client abort transmission of a request server MAY request that the client abort transmission of a request
without error by triggering a QUIC STOP_SENDING frame with error code without error by triggering a QUIC STOP_SENDING frame with error code
HTTP_EARLY_RESPONSE, sending a complete response, and cleanly closing HTTP_EARLY_RESPONSE, sending a complete response, and cleanly closing
its stream. Clients MUST NOT discard complete responses as a result its stream. Clients MUST NOT discard complete responses as a result
of having their request terminated abruptly, though clients can of having their request terminated abruptly, though clients can
always discard responses at their discretion for other reasons. always discard responses at their discretion for other reasons.
Changes to the state of a request stream, including receiving a
RST_STREAM with any error code, do not affect the state of the
server's response. Servers do not abort a response in progress
solely due to a state change on the request stream. However, if the
request stream terminates without containing a usable HTTP request,
the server SHOULD abort its response with the error code
HTTP_INCOMPLETE_REQUEST.
5.1.1. Header Formatting and Compression 5.1.1. Header Formatting and Compression
HTTP message headers carry information as a series of key-value HTTP message headers carry information as a series of key-value
pairs, called header fields. For a listing of registered HTTP header pairs, called header fields. For a listing of registered HTTP header
fields, see the "Message Header Field" registry maintained at fields, see the "Message Header Field" registry maintained at
https://www.iana.org/assignments/message-headers [4]. https://www.iana.org/assignments/message-headers [4].
Just as in previous versions of HTTP, header field names are strings Just as in previous versions of HTTP, header field names are strings
of ASCII characters that are compared in a case-insensitive fashion. of ASCII characters that are compared in a case-insensitive fashion.
Properties of HTTP header field names and values are discussed in Properties of HTTP header field names and values are discussed in
more detail in Section 3.2 of [RFC7230], though the wire rendering in more detail in Section 3.2 of [RFC7230], though the wire rendering in
HTTP/QUIC differs. As in HTTP/2, header field names MUST be HTTP/3 differs. As in HTTP/2, header field names MUST be converted
converted to lowercase prior to their encoding. A request or to lowercase prior to their encoding. A request or response
response containing uppercase header field names MUST be treated as containing uppercase header field names MUST be treated as malformed.
malformed.
As in HTTP/2, HTTP/QUIC uses special pseudo-header fields beginning As in HTTP/2, HTTP/3 uses special pseudo-header fields beginning with
with the ':' character (ASCII 0x3a) to convey the target URI, the the ':' character (ASCII 0x3a) to convey the target URI, the method
method of the request, and the status code for the response. These of the request, and the status code for the response. These pseudo-
pseudo-header fields are defined in Section 8.1.2.3 and 8.1.2.4 of header fields are defined in Section 8.1.2.3 and 8.1.2.4 of
[RFC7540]. Pseudo-header fields are not HTTP header fields. [RFC7540]. Pseudo-header fields are not HTTP header fields.
Endpoints MUST NOT generate pseudo-header fields other than those Endpoints MUST NOT generate pseudo-header fields other than those
defined in [RFC7540]. The restrictions on the use of pseudo-header defined in [RFC7540]. The restrictions on the use of pseudo-header
fields in Section 8.1.2.1 of [RFC7540] also apply to HTTP/QUIC. fields in Section 8.1.2.1 of [RFC7540] also apply to HTTP/3.
HTTP/QUIC uses QPACK header compression as described in [QPACK], a HTTP/3 uses QPACK header compression as described in [QPACK], a
variation of HPACK which allows the flexibility to avoid header- variation of HPACK which allows the flexibility to avoid header-
compression-induced head-of-line blocking. See that document for compression-induced head-of-line blocking. See that document for
additional details. additional details.
An HTTP/QUIC implementation MAY impose a limit on the maximum size of An HTTP/3 implementation MAY impose a limit on the maximum size of
the header it will accept on an individual HTTP message. This limit the header it will accept on an individual HTTP message; encountering
is conveyed as a number of octets in the a larger message header SHOULD be treated as a stream error of type
"HTTP_EXCESSIVE_LOAD". If an implementation wishes to advise its
peer of this limit, it can be conveyed as a number of bytes in the
"SETTINGS_MAX_HEADER_LIST_SIZE" parameter. The size of a header list "SETTINGS_MAX_HEADER_LIST_SIZE" parameter. The size of a header list
is calculated based on the uncompressed size of header fields, is calculated based on the uncompressed size of header fields,
including the length of the name and value in octets plus an overhead including the length of the name and value in bytes plus an overhead
of 32 octets for each header field. Encountering a message header of 32 bytes for each header field.
larger than this value SHOULD be treated as a stream error of type
"HTTP_EXCESSIVE_LOAD".
5.1.2. Request Cancellation 5.1.2. Request Cancellation
Either client or server can cancel requests by aborting the stream Either client or server can cancel requests by aborting the stream
(QUIC RST_STREAM and/or STOP_SENDING frames, as appropriate) with an (QUIC RESET_STREAM and/or STOP_SENDING frames, as appropriate) with
error code of HTTP_REQUEST_CANCELLED (Section 8.1). When the client an error code of HTTP_REQUEST_CANCELLED (Section 8.1). When the
cancels a response, it indicates that this response is no longer of client cancels a response, it indicates that this response is no
interest. Implementations SHOULD cancel requests by aborting both longer of interest. Implementations SHOULD cancel requests by
directions of a stream. aborting both directions of a stream.
When the server aborts its response stream using When the server aborts its response stream using
HTTP_REQUEST_CANCELLED, it indicates that no application processing HTTP_REQUEST_CANCELLED, it indicates that no application processing
was performed. The client can treat requests cancelled by the server was performed. The client can treat requests cancelled by the server
as though they had never been sent at all, thereby allowing them to as though they had never been sent at all, thereby allowing them to
be retried later on a new connection. Servers MUST NOT use the be retried later on a new connection. Servers MUST NOT use the
HTTP_REQUEST_CANCELLED status for requests which were partially or HTTP_REQUEST_CANCELLED status for requests which were partially or
fully processed. fully processed.
Note: In this context, "processed" means that some data from the Note: In this context, "processed" means that some data from the
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5.2. The CONNECT Method 5.2. The CONNECT Method
The pseudo-method CONNECT ([RFC7231], Section 4.3.6) is primarily The pseudo-method CONNECT ([RFC7231], Section 4.3.6) is primarily
used with HTTP proxies to establish a TLS session with an origin used with HTTP proxies to establish a TLS session with an origin
server for the purposes of interacting with "https" resources. In server for the purposes of interacting with "https" resources. In
HTTP/1.x, CONNECT is used to convert an entire HTTP connection into a HTTP/1.x, CONNECT is used to convert an entire HTTP connection into a
tunnel to a remote host. In HTTP/2, the CONNECT method is used to tunnel to a remote host. In HTTP/2, the CONNECT method is used to
establish a tunnel over a single HTTP/2 stream to a remote host for establish a tunnel over a single HTTP/2 stream to a remote host for
similar purposes. similar purposes.
A CONNECT request in HTTP/QUIC functions in the same manner as in A CONNECT request in HTTP/3 functions in the same manner as in
HTTP/2. The request MUST be formatted as described in [RFC7540], HTTP/2. The request MUST be formatted as described in [RFC7540],
Section 8.3. A CONNECT request that does not conform to these Section 8.3. A CONNECT request that does not conform to these
restrictions is malformed. The request stream MUST NOT be closed at restrictions is malformed. The request stream MUST NOT be closed at
the end of the request. the end of the request.
A proxy that supports CONNECT establishes a TCP connection A proxy that supports CONNECT establishes a TCP connection
([RFC0793]) to the server identified in the ":authority" pseudo- ([RFC0793]) to the server identified in the ":authority" pseudo-
header field. Once this connection is successfully established, the header field. Once this connection is successfully established, the
proxy sends a HEADERS frame containing a 2xx series status code to proxy sends a HEADERS frame containing a 2xx series status code to
the client, as defined in [RFC7231], Section 4.3.6. the client, as defined in [RFC7231], Section 4.3.6.
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The TCP connection can be closed by either peer. When the client The TCP connection can be closed by either peer. When the client
ends the request stream (that is, the receive stream at the proxy ends the request stream (that is, the receive stream at the proxy
enters the "Data Recvd" state), the proxy will set the FIN bit on its enters the "Data Recvd" state), the proxy will set the FIN bit on its
connection to the TCP server. When the proxy receives a packet with connection to the TCP server. When the proxy receives a packet with
the FIN bit set, it will terminate the send stream that it sends to the FIN bit set, it will terminate the send stream that it sends to
the client. TCP connections which remain half-closed in a single the client. TCP connections which remain half-closed in a single
direction are not invalid, but are often handled poorly by servers, direction are not invalid, but are often handled poorly by servers,
so clients SHOULD NOT close a stream for sending while they still so clients SHOULD NOT close a stream for sending while they still
expect to receive data from the target of the CONNECT. expect to receive data from the target of the CONNECT.
A TCP connection error is signaled with RST_STREAM. A proxy treats A TCP connection error is signaled with QUIC RESET_STREAM frame. A
any error in the TCP connection, which includes receiving a TCP proxy treats any error in the TCP connection, which includes
segment with the RST bit set, as a stream error of type receiving a TCP segment with the RST bit set, as a stream error of
HTTP_CONNECT_ERROR (Section 8.1). Correspondingly, a proxy MUST send type HTTP_CONNECT_ERROR (Section 8.1). Correspondingly, a proxy MUST
a TCP segment with the RST bit set if it detects an error with the send a TCP segment with the RST bit set if it detects an error with
stream or the QUIC connection. the stream or the QUIC connection.
5.3. Request Prioritization 5.3. Request Prioritization
HTTP/QUIC uses a priority scheme similar to that described in HTTP/3 uses a priority scheme similar to that described in [RFC7540],
[RFC7540], Section 5.3. In this priority scheme, a given stream can Section 5.3. In this priority scheme, a given stream can be
be designated as dependent upon another request, which expresses the designated as dependent upon another request, which expresses the
preference that the latter stream (the "parent" request) be allocated preference that the latter stream (the "parent" request) be allocated
resources before the former stream (the "dependent" request). Taken resources before the former stream (the "dependent" request). Taken
together, the dependencies across all requests in a connection form a together, the dependencies across all requests in a connection form a
dependency tree. The structure of the dependency tree changes as dependency tree.
PRIORITY frames add, remove, or change the dependency links between
requests.
The PRIORITY frame Section 4.2.3 identifies a prioritized element. When a client request is first sent, its parent and weight are
The elements which can be prioritized are: determined by the PRIORITY frame (see Section 4.2.3) which begins the
stream, if present. Otherwise, the element is dependent on the root
of the priority tree. Placeholders are also dependent on the root of
the priority tree when first allocated. Pushed streams are initially
dependent on the client request on which the PUSH_PROMISE frame was
sent. In all cases, elements are assigned an initial weight of 16
unless an PRIORITY frame begins the stream.
The structure of the dependency tree changes as PRIORITY frames on
the control stream modify the dependency links between requests. The
PRIORITY frame Section 4.2.3 identifies a prioritized element. The
elements which can be prioritized are:
o Requests, identified by the ID of the request stream o Requests, identified by the ID of the request stream
o Pushes, identified by the Push ID of the promised resource o Pushes, identified by the Push ID of the promised resource
(Section 4.2.6) (Section 4.2.6)
o Placeholders, identified by a Placeholder ID o Placeholders, identified by a Placeholder ID
An element can depend on another element or on the root of the tree. An element can depend on another element or on the root of the tree.
A reference to an element which is no longer in the tree is treated A reference to an element which is no longer in the tree is treated
as a reference to the root of the tree. as a reference to the root of the tree.
Due to reordering between streams, an element can also be prioritized
which is not yet in the tree. Such elements are added to the tree
with the requested priority.
5.3.1. Placeholders 5.3.1. Placeholders
In HTTP/2, certain implementations used closed or unused streams as In HTTP/2, certain implementations used closed or unused streams as
placeholders in describing the relative priority of requests. placeholders in describing the relative priority of requests. This
However, this created confusion as servers could not reliably created confusion as servers could not reliably identify which
identify which elements of the priority tree could safely be elements of the priority tree could be discarded safely. Clients
discarded. Clients could potentially reference closed streams long could potentially reference closed streams long after the server had
after the server had discarded state, leading to disparate views of discarded state, leading to disparate views of the prioritization the
the prioritization the client had attempted to express. client had attempted to express.
In HTTP/QUIC, a number of placeholders are explicitly permitted by In HTTP/3, a number of placeholders are explicitly permitted by the
the server using the "SETTINGS_NUM_PLACEHOLDERS" setting. Because server using the "SETTINGS_NUM_PLACEHOLDERS" setting. Because the
the server commits to maintain these IDs in the tree, clients can use server commits to maintaining these IDs in the tree, clients can use
them with confidence that the server will not have discarded the them with confidence that the server will not have discarded the
state. state. Clients MUST NOT send the "SETTINGS_NUM_PLACEHOLDERS"
setting; receipt of this setting by a server MUST be treated as a
connection error of type "HTTP_WRONG_SETTING_DIRECTION".
Placeholders are identified by an ID between zero and one less than Placeholders are identified by an ID between zero and one less than
the number of placeholders the server has permitted. the number of placeholders the server has permitted.
Like streams, placeholders have priority information associated with
them.
5.3.2. Priority Tree Maintenance 5.3.2. Priority Tree Maintenance
Servers can aggressively prune inactive regions from the priority Servers can aggressively prune inactive regions from the priority
tree, because placeholders will be used to "root" any persistent tree, because placeholders will be used to "root" any persistent
structure of the tree which the client cares about retaining. For structure of the tree which the client cares about retaining. For
prioritization purposes, a node in the tree is considered "inactive" prioritization purposes, a node in the tree is considered "inactive"
when the corresponding stream has been closed for at least two round- when the corresponding stream has been closed for at least two round-
trip times (using any reasonable estimate available on the server). trip times (using any reasonable estimate available on the server).
This delay helps mitigate race conditions where the server has pruned This delay helps mitigate race conditions where the server has pruned
a node the client believed was still active and used as a Stream a node the client believed was still active and used as a Stream
skipping to change at page 25, line 13 skipping to change at page 27, line 4
Dependency. Dependency.
Specifically, the server MAY at any time: Specifically, the server MAY at any time:
o Identify and discard branches of the tree containing only inactive o Identify and discard branches of the tree containing only inactive
nodes (i.e. a node with only other inactive nodes as descendants, nodes (i.e. a node with only other inactive nodes as descendants,
along with those descendants) along with those descendants)
o Identify and condense interior regions of the tree containing only o Identify and condense interior regions of the tree containing only
inactive nodes, allocating weight appropriately inactive nodes, allocating weight appropriately
x x x x x x
| | | | | |
P P P P P P
/ \ | | / \ | |
I I ==> I ==> A I I ==> I ==> A
/ \ | | / \ | |
A I A A A I A A
| | | |
A A A A
Figure 12: Example of Priority Tree Pruning Figure 13: Example of Priority Tree Pruning
In the example in Figure 12, "P" represents a Placeholder, "A" In the example in Figure 13, "P" represents a Placeholder, "A"
represents an active node, and "I" represents an inactive node. In represents an active node, and "I" represents an inactive node. In
the first step, the server discards two inactive branches (each a the first step, the server discards two inactive branches (each a
single node). In the second step, the server condenses an interior single node). In the second step, the server condenses an interior
inactive node. Note that these transformations will result in no inactive node. Note that these transformations will result in no
change in the resources allocated to a particular active stream. change in the resources allocated to a particular active stream.
Clients SHOULD assume the server is actively performing such pruning Clients SHOULD assume the server is actively performing such pruning
and SHOULD NOT declare a dependency on a stream it knows to have been and SHOULD NOT declare a dependency on a stream it knows to have been
closed. closed.
5.4. Server Push 5.4. Server Push
HTTP/QUIC server push is similar to what is described in HTTP/2 HTTP/3 server push is similar to what is described in HTTP/2
[RFC7540], but uses different mechanisms. [RFC7540], but uses different mechanisms.
Each server push is identified by a unique Push ID. The same Push ID Each server push is identified by a unique Push ID. This Push ID is
can be used in one or more PUSH_PROMISE frames (see Section 4.2.6), used in a single PUSH_PROMISE frame (see Section 4.2.6) which carries
then included with the push stream which ultimately fulfills those the request headers, possibly included in one or more DUPLICATE_PUSH
promises. frames (see Section 4.2.9), then included with the push stream which
ultimately fulfills those promises.
Server push is only enabled on a connection when a client sends a Server push is only enabled on a connection when a client sends a
MAX_PUSH_ID frame (see Section 4.2.8). A server cannot use server MAX_PUSH_ID frame (see Section 4.2.8). A server cannot use server
push until it receives a MAX_PUSH_ID frame. A client sends push until it receives a MAX_PUSH_ID frame. A client sends
additional MAX_PUSH_ID frames to control the number of pushes that a additional MAX_PUSH_ID frames to control the number of pushes that a
server can promise. A server SHOULD use Push IDs sequentially, server can promise. A server SHOULD use Push IDs sequentially,
starting at 0. A client MUST treat receipt of a push stream with a starting at 0. A client MUST treat receipt of a push stream with a
Push ID that is greater than the maximum Push ID as a connection Push ID that is greater than the maximum Push ID as a connection
error of type HTTP_PUSH_LIMIT_EXCEEDED. error of type HTTP_PUSH_LIMIT_EXCEEDED.
The header of the request message is carried by a PUSH_PROMISE frame The header of the request message is carried by a PUSH_PROMISE frame
(see Section 4.2.6) on the request stream which generated the push. (see Section 4.2.6) on the request stream which generated the push.
This allows the server push to be associated with a client request. This allows the server push to be associated with a client request.
Ordering of a PUSH_PROMISE in relation to certain parts of the Ordering of a PUSH_PROMISE in relation to certain parts of the
response is important (see Section 8.2.1 of [RFC7540]). Promised response is important (see Section 8.2.1 of [RFC7540]). Promised
requests MUST conform to the requirements in Section 8.2 of requests MUST conform to the requirements in Section 8.2 of
[RFC7540]. [RFC7540].
The same server push can be associated with additional client
requests using a DUPLICATE_PUSH frame (see Section 4.2.9). Ordering
of a DUPLICATE_PUSH in relation to certain parts of the response is
similarly important. Due to reordering, DUPLICATE_PUSH frames can
arrive before the corresponding PUSH_PROMISE frame, in which case the
request headers of the push would not be immediately available.
Clients which receive a DUPLICATE_PUSH frame for an as-yet-unknown
Push ID can either delay generating new requests for content
referenced following the DUPLICATE_PUSH frame until the request
headers become available, or can initiate requests for discovered
resources and cancel the requests if the requested resource is
already being pushed.
When a server later fulfills a promise, the server push response is When a server later fulfills a promise, the server push response is
conveyed on a push stream (see Section 3.2.2). The push stream conveyed on a push stream (see Section 3.2.2). The push stream
identifies the Push ID of the promise that it fulfills, then contains identifies the Push ID of the promise that it fulfills, then contains
a response to the promised request using the same format described a response to the promised request using the same format described
for responses in Section 5.1. for responses in Section 5.1.
If a promised server push is not needed by the client, the client If a promised server push is not needed by the client, the client
SHOULD send a CANCEL_PUSH frame. If the push stream is already open SHOULD send a CANCEL_PUSH frame. If the push stream is already open
or opens after sending the CANCEL_PUSH frame, a QUIC STOP_SENDING or opens after sending the CANCEL_PUSH frame, a QUIC STOP_SENDING
frame with an appropriate error code can also be used (e.g., frame with an appropriate error code can also be used (e.g.,
HTTP_PUSH_REFUSED, HTTP_PUSH_ALREADY_IN_CACHE; see Section 8). This HTTP_PUSH_REFUSED, HTTP_PUSH_ALREADY_IN_CACHE; see Section 8). This
asks the server not to transfer additional data and indicates that it asks the server not to transfer additional data and indicates that it
will be discarded upon receipt. will be discarded upon receipt.
6. Connection Closure 6. Connection Closure
Once established, an HTTP/QUIC connection can be used for many Once established, an HTTP/3 connection can be used for many requests
requests and responses over time until the connection is closed. and responses over time until the connection is closed. Connection
Connection closure can happen in any of several different ways. closure can happen in any of several different ways.
6.1. Idle Connections 6.1. Idle Connections
Each QUIC endpoint declares an idle timeout during the handshake. If Each QUIC endpoint declares an idle timeout during the handshake. If
the connection remains idle (no packets received) for longer than the connection remains idle (no packets received) for longer than
this duration, the peer will assume that the connection has been this duration, the peer will assume that the connection has been
closed. HTTP/QUIC implementations will need to open a new connection closed. HTTP/3 implementations will need to open a new connection
for new requests if the existing connection has been idle for longer for new requests if the existing connection has been idle for longer
than the server's advertised idle timeout, and SHOULD do so if than the server's advertised idle timeout, and SHOULD do so if
approaching the idle timeout. approaching the idle timeout.
HTTP clients are expected to use QUIC PING frames to keep connections HTTP clients are expected to use QUIC PING frames to keep connections
open while there are responses outstanding for requests or server open while there are responses outstanding for requests or server
pushes. If the client is not expecting a response from the server, pushes. If the client is not expecting a response from the server,
allowing an idle connection to time out is preferred over expending allowing an idle connection to time out is preferred over expending
effort maintaining a connection that might not be needed. A gateway effort maintaining a connection that might not be needed. A gateway
MAY use PING to maintain connections in anticipation of need rather MAY use PING to maintain connections in anticipation of need rather
skipping to change at page 28, line 29 skipping to change at page 30, line 32
an updated last Stream ID. This ensures that a connection can be an updated last Stream ID. This ensures that a connection can be
cleanly shut down without losing requests. cleanly shut down without losing requests.
Once all accepted requests have been processed, the server can permit Once all accepted requests have been processed, the server can permit
the connection to become idle, or MAY initiate an immediate closure the connection to become idle, or MAY initiate an immediate closure
of the connection. An endpoint that completes a graceful shutdown of the connection. An endpoint that completes a graceful shutdown
SHOULD use the HTTP_NO_ERROR code when closing the connection. SHOULD use the HTTP_NO_ERROR code when closing the connection.
6.3. Immediate Application Closure 6.3. Immediate Application Closure
An HTTP/QUIC implementation can immediately close the QUIC connection An HTTP/3 implementation can immediately close the QUIC connection at
at any time. This results in sending a QUIC APPLICATION_CLOSE frame any time. This results in sending a QUIC CONNECTION_CLOSE frame to
to the peer; the error code in this frame indicates to the peer why the peer; the error code in this frame indicates to the peer why the
the connection is being closed. See Section 8 for error codes which connection is being closed. See Section 8 for error codes which can
can be used when closing a connection. be used when closing a connection.
Before closing the connection, a GOAWAY MAY be sent to allow the Before closing the connection, a GOAWAY MAY be sent to allow the
client to retry some requests. Including the GOAWAY frame in the client to retry some requests. Including the GOAWAY frame in the
same packet as the QUIC APPLICATION_CLOSE frame improves the chances same packet as the QUIC CONNECTION_CLOSE frame improves the chances
of the frame being received by clients. of the frame being received by clients.
6.4. Transport Closure 6.4. Transport Closure
For various reasons, the QUIC transport could indicate to the For various reasons, the QUIC transport could indicate to the
application layer that the connection has terminated. This might be application layer that the connection has terminated. This might be
due to an explicit closure by the peer, a transport-level error, or a due to an explicit closure by the peer, a transport-level error, or a
change in network topology which interrupts connectivity. change in network topology which interrupts connectivity.
If a connection terminates without a GOAWAY frame, clients MUST If a connection terminates without a GOAWAY frame, clients MUST
assume that any request which was sent, whether in whole or in part, assume that any request which was sent, whether in whole or in part,
might have been processed. might have been processed.
7. Extensions to HTTP/QUIC 7. Extensions to HTTP/3
HTTP/QUIC permits extension of the protocol. Within the limitations HTTP/3 permits extension of the protocol. Within the limitations
described in this section, protocol extensions can be used to provide described in this section, protocol extensions can be used to provide
additional services or alter any aspect of the protocol. Extensions additional services or alter any aspect of the protocol. Extensions
are effective only within the scope of a single HTTP/QUIC connection. are effective only within the scope of a single HTTP/3 connection.
This applies to the protocol elements defined in this document. This This applies to the protocol elements defined in this document. This
does not affect the existing options for extending HTTP, such as does not affect the existing options for extending HTTP, such as
defining new methods, status codes, or header fields. defining new methods, status codes, or header fields.
Extensions are permitted to use new frame types (Section 4.2), new Extensions are permitted to use new frame types (Section 4.2), new
settings (Section 4.2.5.1), new error codes (Section 8), or new settings (Section 4.2.5.1), new error codes (Section 8), or new
unidirectional stream types (Section 3.2). Registries are unidirectional stream types (Section 3.2). Registries are
established for managing these extension points: frame types established for managing these extension points: frame types
(Section 10.3), settings (Section 10.4), error codes (Section 10.5), (Section 10.3), settings (Section 10.4), error codes (Section 10.5),
skipping to change at page 30, line 5 skipping to change at page 32, line 7
setting is omitted. setting is omitted.
8. Error Handling 8. Error Handling
QUIC allows the application to abruptly terminate (reset) individual QUIC allows the application to abruptly terminate (reset) individual
streams or the entire connection when an error is encountered. These streams or the entire connection when an error is encountered. These
are referred to as "stream errors" or "connection errors" and are are referred to as "stream errors" or "connection errors" and are
described in more detail in [QUIC-TRANSPORT]. An endpoint MAY choose described in more detail in [QUIC-TRANSPORT]. An endpoint MAY choose
to treat a stream error as a connection error. to treat a stream error as a connection error.
This section describes HTTP/QUIC-specific error codes which can be This section describes HTTP/3-specific error codes which can be used
used to express the cause of a connection or stream error. to express the cause of a connection or stream error.
8.1. HTTP/QUIC Error Codes
The following error codes are defined for use in QUIC RST_STREAM, 8.1. HTTP/3 Error Codes
STOP_SENDING, and APPLICATION_CLOSE frames when using HTTP/QUIC.
STOPPING (0x00): This value is reserved by the transport to be used The following error codes are defined for use in QUIC RESET_STREAM
in response to QUIC STOP_SENDING frames. frames, STOP_SENDING frames, and CONNECTION_CLOSE frames when using
HTTP/3.
HTTP_NO_ERROR (0x01): No error. This is used when the connection or HTTP_NO_ERROR (0x00): No error. This is used when the connection or
stream needs to be closed, but there is no error to signal. stream needs to be closed, but there is no error to signal.
HTTP_WRONG_SETTING_DIRECTION (0x01): A client-only setting was sent
by a server, or a server-only setting by a client.
HTTP_PUSH_REFUSED (0x02): The server has attempted to push content HTTP_PUSH_REFUSED (0x02): The server has attempted to push content
which the client will not accept on this connection. which the client will not accept on this connection.
HTTP_INTERNAL_ERROR (0x03): An internal error has occurred in the HTTP_INTERNAL_ERROR (0x03): An internal error has occurred in the
HTTP stack. HTTP stack.
HTTP_PUSH_ALREADY_IN_CACHE (0x04): The server has attempted to push HTTP_PUSH_ALREADY_IN_CACHE (0x04): The server has attempted to push
content which the client has cached. content which the client has cached.
HTTP_REQUEST_CANCELLED (0x05): The client no longer needs the HTTP_REQUEST_CANCELLED (0x05): The client no longer needs the
skipping to change at page 30, line 41 skipping to change at page 32, line 44
HTTP_INCOMPLETE_REQUEST (0x06): The client's stream terminated HTTP_INCOMPLETE_REQUEST (0x06): The client's stream terminated
without containing a fully-formed request. without containing a fully-formed request.
HTTP_CONNECT_ERROR (0x07): The connection established in response to HTTP_CONNECT_ERROR (0x07): The connection established in response to
a CONNECT request was reset or abnormally closed. a CONNECT request was reset or abnormally closed.
HTTP_EXCESSIVE_LOAD (0x08): The endpoint detected that its peer is HTTP_EXCESSIVE_LOAD (0x08): The endpoint detected that its peer is
exhibiting a behavior that might be generating excessive load. exhibiting a behavior that might be generating excessive load.
HTTP_VERSION_FALLBACK (0x09): The requested operation cannot be HTTP_VERSION_FALLBACK (0x09): The requested operation cannot be
served over HTTP/QUIC. The peer should retry over HTTP/1.1. served over HTTP/3. The peer should retry over HTTP/1.1.
HTTP_WRONG_STREAM (0x0A): A frame was received on a stream where it HTTP_WRONG_STREAM (0x0A): A frame was received on a stream where it
is not permitted. is not permitted.
HTTP_PUSH_LIMIT_EXCEEDED (0x0B): A Push ID greater than the current HTTP_PUSH_LIMIT_EXCEEDED (0x0B): A Push ID greater than the current
maximum Push ID was referenced. maximum Push ID was referenced.
HTTP_DUPLICATE_PUSH (0x0C): A Push ID was referenced in two HTTP_DUPLICATE_PUSH (0x0C): A Push ID was referenced in two
different stream headers. different stream headers.
skipping to change at page 31, line 24 skipping to change at page 33, line 27
HTTP_WRONG_STREAM_DIRECTION (0x0010): A unidirectional stream type HTTP_WRONG_STREAM_DIRECTION (0x0010): A unidirectional stream type
was used by a peer which is not permitted to do so. was used by a peer which is not permitted to do so.
HTTP_EARLY_RESPONSE (0x0011): The remainder of the client's request HTTP_EARLY_RESPONSE (0x0011): The remainder of the client's request
is not needed to produce a response. For use in STOP_SENDING is not needed to produce a response. For use in STOP_SENDING
only. only.
HTTP_MISSING_SETTINGS (0x0012): No SETTINGS frame was received at HTTP_MISSING_SETTINGS (0x0012): No SETTINGS frame was received at
the beginning of the control stream. the beginning of the control stream.
HTTP_UNEXPECTED_FRAME (0x0013): A frame was received which was not
permitted in the current state.
HTTP_GENERAL_PROTOCOL_ERROR (0x00FF): Peer violated protocol HTTP_GENERAL_PROTOCOL_ERROR (0x00FF): Peer violated protocol
requirements in a way which doesn't match a more specific error requirements in a way which doesn't match a more specific error
code, or endpoint declines to use the more specific error code. code, or endpoint declines to use the more specific error code.
HTTP_MALFORMED_FRAME (0x01XX): An error in a specific frame type. HTTP_MALFORMED_FRAME (0x01XX): An error in a specific frame type.
The frame type is included as the last octet of the error code. The frame type is included as the last byte of the error code.
For example, an error in a MAX_PUSH_ID frame would be indicated For example, an error in a MAX_PUSH_ID frame would be indicated
with the code (0x10D). with the code (0x10D).
9. Security Considerations 9. Security Considerations
The security considerations of HTTP/QUIC should be comparable to The security considerations of HTTP/3 should be comparable to those
those of HTTP/2 with TLS. Note that where HTTP/2 employs PADDING of HTTP/2 with TLS. Note that where HTTP/2 employs PADDING frames
frames and Padding fields in other frames to make a connection more and Padding fields in other frames to make a connection more
resistant to traffic analysis, HTTP/QUIC can rely on QUIC PADDING resistant to traffic analysis, HTTP/3 can rely on QUIC PADDING frames
frames or employ the reserved frame and stream types discussed in or employ the reserved frame and stream types discussed in
Section 4.2.9 and Section 3.2.3. Section 4.2.10 and Section 3.2.3.
When HTTP Alternative Services is used for discovery for HTTP/QUIC When HTTP Alternative Services is used for discovery for HTTP/3
endpoints, the security considerations of [ALTSVC] also apply. endpoints, the security considerations of [ALTSVC] also apply.
Several protocol elements contain nested length elements, typically Several protocol elements contain nested length elements, typically
in the form of frames with an explicit length containing variable- in the form of frames with an explicit length containing variable-
length integers. This could pose a security risk to an incautious length integers. This could pose a security risk to an incautious
implementer. An implementation MUST ensure that the length of a implementer. An implementation MUST ensure that the length of a
frame exactly matches the length of the fields it contains. frame exactly matches the length of the fields it contains.
10. IANA Considerations 10. IANA Considerations
10.1. Registration of HTTP/QUIC Identification String 10.1. Registration of HTTP/3 Identification String
This document creates a new registration for the identification of This document creates a new registration for the identification of
HTTP/QUIC in the "Application Layer Protocol Negotiation (ALPN) HTTP/3 in the "Application Layer Protocol Negotiation (ALPN) Protocol
Protocol IDs" registry established in [RFC7301]. IDs" registry established in [RFC7301].
The "hq" string identifies HTTP/QUIC: The "h3" string identifies HTTP/3:
Protocol: HTTP/QUIC Protocol: HTTP/3
Identification Sequence: 0x68 0x71 ("hq") Identification Sequence: 0x68 0x33 ("h3")
Specification: This document Specification: This document
10.2. Registration of QUIC Version Hint Alt-Svc Parameter 10.2. Registration of QUIC Version Hint Alt-Svc Parameter
This document creates a new registration for version-negotiation This document creates a new registration for version-negotiation
hints in the "Hypertext Transfer Protocol (HTTP) Alt-Svc Parameter" hints in the "Hypertext Transfer Protocol (HTTP) Alt-Svc Parameter"
registry established in [RFC7838]. registry established in [RFC7838].
Parameter: "quic" Parameter: "quic"
Specification: This document, Section 2.2.1 Specification: This document, Section 2.2.1
10.3. Frame Types 10.3. Frame Types
This document establishes a registry for HTTP/QUIC frame type codes. This document establishes a registry for HTTP/3 frame type codes.
The "HTTP/QUIC Frame Type" registry manages an 8-bit space. The The "HTTP/3 Frame Type" registry manages an 8-bit space. The "HTTP/3
"HTTP/QUIC Frame Type" registry operates under either of the "IETF Frame Type" registry operates under either of the "IETF Review" or
Review" or "IESG Approval" policies [RFC8126] for values from 0x00 up "IESG Approval" policies [RFC8126] for values from 0x00 up to and
to and including 0xef, with values from 0xf0 up to and including 0xff including 0xef, with values from 0xf0 up to and including 0xff being
being reserved for Experimental Use. reserved for Experimental Use.
While this registry is separate from the "HTTP/2 Frame Type" registry While this registry is separate from the "HTTP/2 Frame Type" registry
defined in [RFC7540], it is preferable that the assignments parallel defined in [RFC7540], it is preferable that the assignments parallel
each other. If an entry is present in only one registry, every each other. If an entry is present in only one registry, every
effort SHOULD be made to avoid assigning the corresponding value to effort SHOULD be made to avoid assigning the corresponding value to
an unrelated operation. an unrelated operation.
New entries in this registry require the following information: New entries in this registry require the following information:
Frame Type: A name or label for the frame type. Frame Type: A name or label for the frame type.
Code: The 8-bit code assigned to the frame type. Code: The 8-bit code assigned to the frame type.
Specification: A reference to a specification that includes a Specification: A reference to a specification that includes a
description of the frame layout and its semantics, including any description of the frame layout and its semantics, including any
parts of the frame that are conditionally present. parts of the frame that are conditionally present.
The entries in the following table are registered by this document. The entries in the following table are registered by this document.
+--------------+------+----------------+ +----------------+------+----------------+
| Frame Type | Code | Specification | | Frame Type | Code | Specification |
+--------------+------+----------------+ +----------------+------+----------------+
| DATA | 0x0 | Section 4.2.1 | | DATA | 0x0 | Section 4.2.1 |
| | | | | | | |
| HEADERS | 0x1 | Section 4.2.2 | | HEADERS | 0x1 | Section 4.2.2 |
| | | | | | | |
| PRIORITY | 0x2 | Section 4.2.3 | | PRIORITY | 0x2 | Section 4.2.3 |
| | | | | | | |
| CANCEL_PUSH | 0x3 | Section 4.2.4 | | CANCEL_PUSH | 0x3 | Section 4.2.4 |
| | | | | | | |
| SETTINGS | 0x4 | Section 4.2.5 | | SETTINGS | 0x4 | Section 4.2.5 |
| | | | | | | |
| PUSH_PROMISE | 0x5 | Section 4.2.6 | | PUSH_PROMISE | 0x5 | Section 4.2.6 |
| | | | | | | |
| Reserved | 0x6 | N/A | | Reserved | 0x6 | N/A |
| | | | | | | |
| GOAWAY | 0x7 | Section 4.2.7 | | GOAWAY | 0x7 | Section 4.2.7 |
| | | | | | | |
| Reserved | 0x8 | N/A | | Reserved | 0x8 | N/A |
| | | | | | | |
| Reserved | 0x9 | N/A | | Reserved | 0x9 | N/A |
| | | | | | | |
| MAX_PUSH_ID | 0xD | Section 4.2.8 | | MAX_PUSH_ID | 0xD | Section 4.2.8 |
+--------------+------+----------------+ | | | |
| DUPLICATE_PUSH | 0xE | Section 4.2.9 |
+----------------+------+----------------+
Additionally, each code of the format "0xb + (0x1f * N)" for values Additionally, each code of the format "0xb + (0x1f * N)" for values
of N in the range (0..7) (that is, "0xb", "0x2a", "0x49", "0x68", of N in the range (0..7) (that is, "0xb", "0x2a", "0x49", "0x68",
"0x87", "0xa6", "0xc5", and "0xe4"), the following values should be "0x87", "0xa6", "0xc5", and "0xe4"), the following values should be
registered: registered:
Frame Type: Reserved - GREASE Frame Type: Reserved - GREASE
Specification: Section 4.2.9 Specification: Section 4.2.10
10.4. Settings Parameters 10.4. Settings Parameters
This document establishes a registry for HTTP/QUIC settings. The This document establishes a registry for HTTP/3 settings. The
"HTTP/QUIC Settings" registry manages a 16-bit space. The "HTTP/QUIC "HTTP/3 Settings" registry manages a 16-bit space. The "HTTP/3
Settings" registry operates under the "Expert Review" policy Settings" registry operates under the "Expert Review" policy
[RFC8126] for values in the range from 0x0000 to 0xefff, with values [RFC8126] for values in the range from 0x0000 to 0xefff, with values
between and 0xf000 and 0xffff being reserved for Experimental Use. between and 0xf000 and 0xffff being reserved for Experimental Use.
The designated experts are the same as those for the "HTTP/2 The designated experts are the same as those for the "HTTP/2
Settings" registry defined in [RFC7540]. Settings" registry defined in [RFC7540].
While this registry is separate from the "HTTP/2 Settings" registry While this registry is separate from the "HTTP/2 Settings" registry
defined in [RFC7540], it is preferable that the assignments parallel defined in [RFC7540], it is preferable that the assignments parallel
each other. If an entry is present in only one registry, every each other. If an entry is present in only one registry, every
effort SHOULD be made to avoid assigning the corresponding value to effort SHOULD be made to avoid assigning the corresponding value to
an unrelated operation. an unrelated operation.
New registrations are advised to provide the following information: New registrations are advised to provide the following information:
skipping to change at page 34, line 31 skipping to change at page 36, line 38
Specification: An optional reference to a specification that Specification: An optional reference to a specification that
describes the use of the setting. describes the use of the setting.
The entries in the following table are registered by this document. The entries in the following table are registered by this document.
+----------------------+------+------------------+ +----------------------+------+------------------+
| Setting Name | Code | Specification | | Setting Name | Code | Specification |
+----------------------+------+------------------+ +----------------------+------+------------------+
| Reserved | 0x2 | N/A | | Reserved | 0x2 | N/A |
| | | | | | | |
| NUM_PLACEHOLDERS | 0x3 | Section 4.2.5.1 | | Reserved | 0x3 | N/A |
| | | | | | | |
| Reserved | 0x4 | N/A | | Reserved | 0x4 | N/A |
| | | | | | | |
| Reserved | 0x5 | N/A | | Reserved | 0x5 | N/A |
| | | | | | | |
| MAX_HEADER_LIST_SIZE | 0x6 | Section 4.2.5.1 | | MAX_HEADER_LIST_SIZE | 0x6 | Section 4.2.5.1 |
| | | |
| NUM_PLACEHOLDERS | 0x8 | Section 4.2.5.1 |
+----------------------+------+------------------+ +----------------------+------+------------------+
Additionally, each code of the format "0x?a?a" where each "?" is any Additionally, each code of the format "0x?a?a" where each "?" is any
four bits (that is, "0x0a0a", "0x0a1a", etc. through "0xfafa"), the four bits (that is, "0x0a0a", "0x0a1a", etc. through "0xfafa"), the
following values should be registered: following values should be registered:
Name: Reserved - GREASE Name: Reserved - GREASE
Specification: Section 4.2.5.1 Specification: Section 4.2.5.1
10.5. Error Codes 10.5. Error Codes
This document establishes a registry for HTTP/QUIC error codes. The This document establishes a registry for HTTP/3 error codes. The
"HTTP/QUIC Error Code" registry manages a 16-bit space. The "HTTP/ "HTTP/3 Error Code" registry manages a 16-bit space. The "HTTP/3
QUIC Error Code" registry operates under the "Expert Review" policy Error Code" registry operates under the "Expert Review" policy
[RFC8126]. [RFC8126].
Registrations for error codes are required to include a description Registrations for error codes are required to include a description
of the error code. An expert reviewer is advised to examine new of the error code. An expert reviewer is advised to examine new
registrations for possible duplication with existing error codes. registrations for possible duplication with existing error codes.
Use of existing registrations is to be encouraged, but not mandated. Use of existing registrations is to be encouraged, but not mandated.
New registrations are advised to provide the following information: New registrations are advised to provide the following information:
Name: A name for the error code. Specifying an error code name is Name: A name for the error code. Specifying an error code name is
skipping to change at page 35, line 27 skipping to change at page 37, line 36
Code: The 16-bit error code value. Code: The 16-bit error code value.
Description: A brief description of the error code semantics, longer Description: A brief description of the error code semantics, longer
if no detailed specification is provided. if no detailed specification is provided.
Specification: An optional reference for a specification that Specification: An optional reference for a specification that
defines the error code. defines the error code.
The entries in the following table are registered by this document. The entries in the following table are registered by this document.
+-------------------------+-------+---------------+-----------------+ +---------------------------+--------+---------------+--------------+
| Name | Code | Description | Specification | | Name | Code | Description | Specificatio |
+-------------------------+-------+---------------+-----------------+ | | | | n |
| STOPPING | 0x000 | Reserved by | [QUIC-TRANSPORT | +---------------------------+--------+---------------+--------------+
| | 0 | QUIC | ] | | HTTP_NO_ERROR | 0x0000 | No error | Section 8.1 |
| | | | | | | | | |
| HTTP_NO_ERROR | 0x000 | No error | Section 8.1 | | HTTP_WRONG_SETTING_DIRECT | 0x0001 | Setting sent | Section 8.1 |
| | 1 | | | | ION | | in wrong | |
| | | | | | | | direction | |
| HTTP_PUSH_REFUSED | 0x000 | Client | Section 8.1 | | | | | |
| | 2 | refused | | | HTTP_PUSH_REFUSED | 0x0002 | Client | Section 8.1 |
| | | pushed | | | | | refused | |
| | | content | | | | | pushed | |
| | | | | | | | content | |
| HTTP_INTERNAL_ERROR | 0x000 | Internal | Section 8.1 | | | | | |
| | 3 | error | | | HTTP_INTERNAL_ERROR | 0x0003 | Internal | Section 8.1 |
| | | | | | | | error | |
| HTTP_PUSH_ALREADY_IN_CA | 0x000 | Pushed | Section 8.1 | | | | | |
| CHE | 4 | content | | | HTTP_PUSH_ALREADY_IN_CACH | 0x0004 | Pushed | Section 8.1 |
| | | already | | | E | | content | |
| | | cached | | | | | already | |
| | | | | | | | cached | |
| HTTP_REQUEST_CANCELLED | 0x000 | Data no | Section 8.1 | | | | | |
| | 5 | longer needed | | | HTTP_REQUEST_CANCELLED | 0x0005 | Data no | Section 8.1 |
| | | | | | | | longer needed | |
| HTTP_INCOMPLETE_REQUEST | 0x000 | Stream | Section 8.1 | | | | | |
| | 6 | terminated | | | HTTP_INCOMPLETE_REQUEST | 0x0006 | Stream | Section 8.1 |
| | | early | | | | | terminated | |
| | | | | | | | early | |
| HTTP_CONNECT_ERROR | 0x000 | TCP reset or | Section 8.1 | | | | | |
| | 7 | error on | | | HTTP_CONNECT_ERROR | 0x0007 | TCP reset or | Section 8.1 |
| | | CONNECT | | | | | error on | |
| | | request | | | | | CONNECT | |
| | | | | | | | request | |
| HTTP_EXCESSIVE_LOAD | 0x000 | Peer | Section 8.1 | | | | | |
| | 8 | generating | | | HTTP_EXCESSIVE_LOAD | 0x0008 | Peer | Section 8.1 |
| | | excessive | | | | | generating | |
| | | load | | | | | excessive | |
| | | | | | | | load | |
| HTTP_VERSION_FALLBACK | 0x000 | Retry over | Section 8.1 | | | | | |
| | 9 | HTTP/1.1 | | | HTTP_VERSION_FALLBACK | 0x0009 | Retry over | Section 8.1 |
| | | | | | | | HTTP/1.1 | |
| HTTP_WRONG_STREAM | 0x000 | A frame was | Section 8.1 | | | | | |
| | A | sent on the | | | HTTP_WRONG_STREAM | 0x000A | A frame was | Section 8.1 |
| | | wrong stream | | | | | sent on the | |
| | | | | | | | wrong stream | |
| HTTP_PUSH_LIMIT_EXCEEDE | 0x000 | Maximum Push | Section 8.1 | | | | | |
| D | B | ID exceeded | | | HTTP_PUSH_LIMIT_EXCEEDED | 0x000B | Maximum Push | Section 8.1 |
| | | | | | | | ID exceeded | |
| HTTP_DUPLICATE_PUSH | 0x000 | Push ID was | Section 8.1 | | | | | |
| | C | fulfilled | | | HTTP_DUPLICATE_PUSH | 0x000C | Push ID was | Section 8.1 |
| | | multiple | | | | | fulfilled | |
| | | times | | | | | multiple | |
| | | | | | | | times | |
| HTTP_UNKNOWN_STREAM_TYP | 0x000 | Unknown unidi | Section 8.1 | | | | | |
| E | D | rectional | | | HTTP_UNKNOWN_STREAM_TYPE | 0x000D | Unknown unidi | Section 8.1 |
| | | stream type | | | | | rectional | |
| | | | | | | | stream type | |
| HTTP_WRONG_STREAM_COUNT | 0x000 | Too many unid | Section 8.1 | | | | | |
| | E | irectional | | | HTTP_WRONG_STREAM_COUNT | 0x000E | Too many unid | Section 8.1 |
| | | streams | | | | | irectional | |
| | | | | | | | streams | |
| HTTP_CLOSED_CRITICAL_ST | 0x000 | Critical | Section 8.1 | | | | | |
| REAM | F | stream was | | | HTTP_CLOSED_CRITICAL_STRE | 0x000F | Critical | Section 8.1 |
| | | closed | | | AM | | stream was | |
| | | | | | | | closed | |
| HTTP_WRONG_STREAM_DIREC | 0x001 | Unidirectiona | Section 8.1 | | | | | |
| TION | 0 | l stream in | | | HTTP_WRONG_STREAM_DIRECTI | 0x0010 | Unidirectiona | Section 8.1 |
| | | wrong | | | ON | | l stream in | |
| | | direction | | | | | wrong | |
| | | | | | | | direction | |
| HTTP_EARLY_RESPONSE | 0x001 | Remainder of | Section 8.1 | | | | | |
| | 1 | request not | | | HTTP_EARLY_RESPONSE | 0x0011 | Remainder of | Section 8.1 |
| | | needed | | | | | request not | |
| | | | | | | | needed | |
| HTTP_MISSING_SETTINGS | 0x001 | No SETTINGS | Section 8.1 | | | | | |
| | 2 | frame | | | HTTP_MISSING_SETTINGS | 0x0012 | No SETTINGS | Section 8.1 |
| | | received | | | | | frame | |
| | | | | | | | received | |
| HTTP_MALFORMED_FRAME | 0x01X | Error in | Section 8.1 | | | | | |
| | X | frame | | | HTTP_UNEXPECTED_FRAME | 0x0013 | Frame not | Section 8.1 |
| | | formatting or | | | | | permitted in | |
| | | use | | | | | the current | |
+-------------------------+-------+---------------+-----------------+ | | | state | |
| | | | |
| HTTP_MALFORMED_FRAME | 0x01XX | Error in | Section 8.1 |
| | | frame | |
| | | formatting | |
+---------------------------+--------+---------------+--------------+
10.6. Stream Types 10.6. Stream Types
This document establishes a registry for HTTP/QUIC unidirectional This document establishes a registry for HTTP/3 unidirectional stream
stream types. The "HTTP/QUIC Stream Type" registry manages an 8-bit types. The "HTTP/3 Stream Type" registry manages an 8-bit space.
space. The "HTTP/QUIC Stream Type" registry operates under either of The "HTTP/3 Stream Type" registry operates under either of the "IETF
the "IETF Review" or "IESG Approval" policies [RFC8126] for values Review" or "IESG Approval" policies [RFC8126] for values from 0x00 up
from 0x00 up to and including 0xef, with values from 0xf0 up to and to and including 0xef, with values from 0xf0 up to and including 0xff
including 0xff being reserved for Experimental Use. being reserved for Experimental Use.
New entries in this registry require the following information: New entries in this registry require the following information:
Stream Type: A name or label for the stream type. Stream Type: A name or label for the stream type.
Code: The 8-bit code assigned to the stream type. Code: The 8-bit code assigned to the stream type.
Specification: A reference to a specification that includes a Specification: A reference to a specification that includes a
description of the stream type, including the layout semantics of description of the stream type, including the layout semantics of
its payload. its payload.
skipping to change at page 38, line 21 skipping to change at page 40, line 34
11. References 11. References
11.1. Normative References 11.1. Normative References
[ALTSVC] Nottingham, M., McManus, P., and J. Reschke, "HTTP [ALTSVC] Nottingham, M., McManus, P., and J. Reschke, "HTTP
Alternative Services", RFC 7838, DOI 10.17487/RFC7838, Alternative Services", RFC 7838, DOI 10.17487/RFC7838,
April 2016, <https://www.rfc-editor.org/info/rfc7838>. April 2016, <https://www.rfc-editor.org/info/rfc7838>.
[QPACK] Krasic, C., Bishop, M., and A. Frindell, Ed., "QPACK: [QPACK] Krasic, C., Bishop, M., and A. Frindell, Ed., "QPACK:
Header Compression for HTTP over QUIC", draft-ietf-quic- Header Compression for HTTP over QUIC", draft-ietf-quic-
qpack-04 (work in progress), October 2018. qpack-latest (work in progress).
[QUIC-TRANSPORT] [QUIC-TRANSPORT]
Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
Multiplexed and Secure Transport", draft-ietf-quic- Multiplexed and Secure Transport", draft-ietf-quic-
transport-16 (work in progress). transport-latest (work in progress).
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7, [RFC0793] Postel, J., "Transmission Control Protocol", STD 7,
RFC 793, DOI 10.17487/RFC0793, September 1981, RFC 793, DOI 10.17487/RFC0793, September 1981,
<https://www.rfc-editor.org/info/rfc793>. <https://www.rfc-editor.org/info/rfc793>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
skipping to change at page 39, line 47 skipping to change at page 42, line 17
[1] https://mailarchive.ietf.org/arch/search/?email_list=quic [1] https://mailarchive.ietf.org/arch/search/?email_list=quic
[2] https://github.com/quicwg [2] https://github.com/quicwg
[3] https://github.com/quicwg/base-drafts/labels/-http [3] https://github.com/quicwg/base-drafts/labels/-http
[4] https://www.iana.org/assignments/message-headers [4] https://www.iana.org/assignments/message-headers
Appendix A. Considerations for Transitioning from HTTP/2 Appendix A. Considerations for Transitioning from HTTP/2
HTTP/QUIC is strongly informed by HTTP/2, and bears many HTTP/3 is strongly informed by HTTP/2, and bears many similarities.
similarities. This section describes the approach taken to design This section describes the approach taken to design HTTP/3, points
HTTP/QUIC, points out important differences from HTTP/2, and out important differences from HTTP/2, and describes how to map
describes how to map HTTP/2 extensions into HTTP/QUIC. HTTP/2 extensions into HTTP/3.
HTTP/QUIC begins from the premise that similarity to HTTP/2 is HTTP/3 begins from the premise that similarity to HTTP/2 is
preferable, but not a hard requirement. HTTP/QUIC departs from preferable, but not a hard requirement. HTTP/3 departs from HTTP/2
HTTP/2 primarily where necessary to accommodate the differences in primarily where necessary to accommodate the differences in behavior
behavior between QUIC and TCP (lack of ordering, support for between QUIC and TCP (lack of ordering, support for streams). We
streams). We intend to avoid gratuitous changes which make it intend to avoid gratuitous changes which make it difficult or
difficult or impossible to build extensions with the same semantics impossible to build extensions with the same semantics applicable to
applicable to both protocols at once. both protocols at once.
These departures are noted in this section. These departures are noted in this section.
A.1. Streams A.1. Streams
HTTP/QUIC permits use of a larger number of streams (2^62-1) than HTTP/3 permits use of a larger number of streams (2^62-1) than
HTTP/2. The considerations about exhaustion of stream identifier HTTP/2. The considerations about exhaustion of stream identifier
space apply, though the space is significantly larger such that it is space apply, though the space is significantly larger such that it is
likely that other limits in QUIC are reached first, such as the limit likely that other limits in QUIC are reached first, such as the limit
on the connection flow control window. on the connection flow control window.
A.2. HTTP Frame Types A.2. HTTP Frame Types
Many framing concepts from HTTP/2 can be elided away on QUIC, because Many framing concepts from HTTP/2 can be elided away on QUIC, because
the transport deals with them. Because frames are already on a the transport deals with them. Because frames are already on a
stream, they can omit the stream number. Because frames do not block stream, they can omit the stream number. Because frames do not block
multiplexing (QUIC's multiplexing occurs below this layer), the multiplexing (QUIC's multiplexing occurs below this layer), the
support for variable-maximum-length packets can be removed. Because support for variable-maximum-length packets can be removed. Because
stream termination is handled by QUIC, an END_STREAM flag is not stream termination is handled by QUIC, an END_STREAM flag is not
required. This permits the removal of the Flags field from the required. This permits the removal of the Flags field from the
generic frame layout. generic frame layout.
Frame payloads are largely drawn from [RFC7540]. However, QUIC Frame payloads are largely drawn from [RFC7540]. However, QUIC
includes many features (e.g. flow control) which are also present in includes many features (e.g. flow control) which are also present in
HTTP/2. In these cases, the HTTP mapping does not re-implement them. HTTP/2. In these cases, the HTTP mapping does not re-implement them.
As a result, several HTTP/2 frame types are not required in HTTP/ As a result, several HTTP/2 frame types are not required in HTTP/3.
QUIC. Where an HTTP/2-defined frame is no longer used, the frame ID Where an HTTP/2-defined frame is no longer used, the frame ID has
has been reserved in order to maximize portability between HTTP/2 and been reserved in order to maximize portability between HTTP/2 and
HTTP/QUIC implementations. However, even equivalent frames between HTTP/3 implementations. However, even equivalent frames between the
the two mappings are not identical. two mappings are not identical.
Many of the differences arise from the fact that HTTP/2 provides an Many of the differences arise from the fact that HTTP/2 provides an
absolute ordering between frames across all streams, while QUIC absolute ordering between frames across all streams, while QUIC
provides this guarantee on each stream only. As a result, if a frame provides this guarantee on each stream only. As a result, if a frame
type makes assumptions that frames from different streams will still type makes assumptions that frames from different streams will still
be received in the order sent, HTTP/QUIC will break them. be received in the order sent, HTTP/3 will break them.
For example, implicit in the HTTP/2 prioritization scheme is the For example, implicit in the HTTP/2 prioritization scheme is the
notion of in-order delivery of priority changes (i.e., dependency notion of in-order delivery of priority changes (i.e., dependency
tree mutations): since operations on the dependency tree such as tree mutations): since operations on the dependency tree such as
reparenting a subtree are not commutative, both sender and receiver reparenting a subtree are not commutative, both sender and receiver
must apply them in the same order to ensure that both sides have a must apply them in the same order to ensure that both sides have a
consistent view of the stream dependency tree. HTTP/2 specifies consistent view of the stream dependency tree. HTTP/2 specifies
priority assignments in PRIORITY frames and (optionally) in HEADERS priority assignments in PRIORITY frames and (optionally) in HEADERS
frames. To achieve in-order delivery of priority changes in HTTP/ frames. To achieve in-order delivery of priority changes in HTTP/3,
QUIC, PRIORITY frames are sent on the control stream and the PRIORITY PRIORITY frames are sent on the control stream and exclusive
section is removed from the HEADERS frame. prioritization has been removed.
Likewise, HPACK was designed with the assumption of in-order Likewise, HPACK was designed with the assumption of in-order
delivery. A sequence of encoded header blocks must arrive (and be delivery. A sequence of encoded header blocks must arrive (and be
decoded) at an endpoint in the same order in which they were encoded. decoded) at an endpoint in the same order in which they were encoded.
This ensures that the dynamic state at the two endpoints remains in This ensures that the dynamic state at the two endpoints remains in
sync. As a result, HTTP/QUIC uses a modified version of HPACK, sync. As a result, HTTP/3 uses a modified version of HPACK,
described in [QPACK]. described in [QPACK].
Frame type definitions in HTTP/QUIC often use the QUIC variable- Frame type definitions in HTTP/3 often use the QUIC variable-length
length integer encoding. In particular, Stream IDs use this integer encoding. In particular, Stream IDs use this encoding, which
encoding, which allow for a larger range of possible values than the allow for a larger range of possible values than the encoding used in
encoding used in HTTP/2. Some frames in HTTP/QUIC use an identifier HTTP/2. Some frames in HTTP/3 use an identifier rather than a Stream
rather than a Stream ID (e.g. Push IDs in PRIORITY frames). ID (e.g. Push IDs in PRIORITY frames). Redefinition of the encoding
Redefinition of the encoding of extension frame types might be of extension frame types might be necessary if the encoding includes
necessary if the encoding includes a Stream ID. a Stream ID.
Because the Flags field is not present in generic HTTP/QUIC frames, Because the Flags field is not present in generic HTTP/3 frames,
those frames which depend on the presence of flags need to allocate those frames which depend on the presence of flags need to allocate
space for flags as part of their frame payload. space for flags as part of their frame payload.
Other than this issue, frame type HTTP/2 extensions are typically Other than this issue, frame type HTTP/2 extensions are typically
portable to QUIC simply by replacing Stream 0 in HTTP/2 with a portable to QUIC simply by replacing Stream 0 in HTTP/2 with a
control stream in HTTP/QUIC. HTTP/QUIC extensions will not assume control stream in HTTP/3. HTTP/3 extensions will not assume
ordering, but would not be harmed by ordering, and would be portable ordering, but would not be harmed by ordering, and would be portable
to HTTP/2 in the same manner. to HTTP/2 in the same manner.
Below is a listing of how each HTTP/2 frame type is mapped: Below is a listing of how each HTTP/2 frame type is mapped:
DATA (0x0): Padding is not defined in HTTP/QUIC frames. See DATA (0x0): Padding is not defined in HTTP/3 frames. See
Section 4.2.1. Section 4.2.1.
HEADERS (0x1): As described above, the PRIORITY region of HEADERS is HEADERS (0x1): As described above, the PRIORITY region of HEADERS is
not supported. A separate PRIORITY frame MUST be used. Padding not supported. A separate PRIORITY frame MUST be used. Padding
is not defined in HTTP/QUIC frames. See Section 4.2.2. is not defined in HTTP/3 frames. See Section 4.2.2.
PRIORITY (0x2): As described above, the PRIORITY frame is sent on PRIORITY (0x2): As described above, the PRIORITY frame is sent on
the control stream and can reference a variety of identifiers. the control stream and can reference a variety of identifiers.
See Section 4.2.3. See Section 4.2.3.
RST_STREAM (0x3): RST_STREAM frames do not exist, since QUIC RST_STREAM (0x3): RST_STREAM frames do not exist, since QUIC
provides stream lifecycle management. The same code point is used provides stream lifecycle management. The same code point is used
for the CANCEL_PUSH frame (Section 4.2.4). for the CANCEL_PUSH frame (Section 4.2.4).
SETTINGS (0x4): SETTINGS frames are sent only at the beginning of SETTINGS (0x4): SETTINGS frames are sent only at the beginning of
skipping to change at page 42, line 25 skipping to change at page 44, line 42
GOAWAY (0x7): GOAWAY is sent only from server to client and does not GOAWAY (0x7): GOAWAY is sent only from server to client and does not
contain an error code. See Section 4.2.7. contain an error code. See Section 4.2.7.
WINDOW_UPDATE (0x8): WINDOW_UPDATE frames do not exist, since QUIC WINDOW_UPDATE (0x8): WINDOW_UPDATE frames do not exist, since QUIC
provides flow control. provides flow control.
CONTINUATION (0x9): CONTINUATION frames do not exist; instead, CONTINUATION (0x9): CONTINUATION frames do not exist; instead,
larger HEADERS/PUSH_PROMISE frames than HTTP/2 are permitted. larger HEADERS/PUSH_PROMISE frames than HTTP/2 are permitted.
Frame types defined by extensions to HTTP/2 need to be separately Frame types defined by extensions to HTTP/2 need to be separately
registered for HTTP/QUIC if still applicable. The IDs of frames registered for HTTP/3 if still applicable. The IDs of frames defined
defined in [RFC7540] have been reserved for simplicity. See in [RFC7540] have been reserved for simplicity. See Section 10.3.
Section 10.3.
A.3. HTTP/2 SETTINGS Parameters A.3. HTTP/2 SETTINGS Parameters
An important difference from HTTP/2 is that settings are sent once, An important difference from HTTP/2 is that settings are sent once,
at the beginning of the connection, and thereafter cannot change. at the beginning of the connection, and thereafter cannot change.
This eliminates many corner cases around synchronization of changes. This eliminates many corner cases around synchronization of changes.
Some transport-level options that HTTP/2 specifies via the SETTINGS Some transport-level options that HTTP/2 specifies via the SETTINGS
frame are superseded by QUIC transport parameters in HTTP/QUIC. The frame are superseded by QUIC transport parameters in HTTP/3. The
HTTP-level options that are retained in HTTP/QUIC have the same value HTTP-level options that are retained in HTTP/3 have the same value as
as in HTTP/2. in HTTP/2.
Below is a listing of how each HTTP/2 SETTINGS parameter is mapped: Below is a listing of how each HTTP/2 SETTINGS parameter is mapped:
SETTINGS_HEADER_TABLE_SIZE: See [QPACK]. SETTINGS_HEADER_TABLE_SIZE: See [QPACK].
SETTINGS_ENABLE_PUSH: This is removed in favor of the MAX_PUSH_ID SETTINGS_ENABLE_PUSH: This is removed in favor of the MAX_PUSH_ID
which provides a more granular control over server push. which provides a more granular control over server push.
SETTINGS_MAX_CONCURRENT_STREAMS: QUIC controls the largest open SETTINGS_MAX_CONCURRENT_STREAMS: QUIC controls the largest open
Stream ID as part of its flow control logic. Specifying Stream ID as part of its flow control logic. Specifying
SETTINGS_MAX_CONCURRENT_STREAMS in the SETTINGS frame is an error. SETTINGS_MAX_CONCURRENT_STREAMS in the SETTINGS frame is an error.
SETTINGS_INITIAL_WINDOW_SIZE: QUIC requires both stream and SETTINGS_INITIAL_WINDOW_SIZE: QUIC requires both stream and
connection flow control window sizes to be specified in the connection flow control window sizes to be specified in the
initial transport handshake. Specifying initial transport handshake. Specifying
SETTINGS_INITIAL_WINDOW_SIZE in the SETTINGS frame is an error. SETTINGS_INITIAL_WINDOW_SIZE in the SETTINGS frame is an error.
SETTINGS_MAX_FRAME_SIZE: This setting has no equivalent in HTTP/ SETTINGS_MAX_FRAME_SIZE: This setting has no equivalent in HTTP/3.
QUIC. Specifying it in the SETTINGS frame is an error. Specifying it in the SETTINGS frame is an error.
SETTINGS_MAX_HEADER_LIST_SIZE: See Section 4.2.5.1. SETTINGS_MAX_HEADER_LIST_SIZE: See Section 4.2.5.1.
In HTTP/QUIC, setting values are variable-length integers (6, 14, 30, In HTTP/3, setting values are variable-length integers (6, 14, 30, or
or 62 bits long) rather than fixed-length 32-bit fields as in HTTP/2. 62 bits long) rather than fixed-length 32-bit fields as in HTTP/2.
This will often produce a shorter encoding, but can produce a longer This will often produce a shorter encoding, but can produce a longer
encoding for settings which use the full 32-bit space. Settings encoding for settings which use the full 32-bit space. Settings
ported from HTTP/2 might choose to redefine the format of their ported from HTTP/2 might choose to redefine the format of their
settings to avoid using the 62-bit encoding. settings to avoid using the 62-bit encoding.
Settings need to be defined separately for HTTP/2 and HTTP/QUIC. The Settings need to be defined separately for HTTP/2 and HTTP/3. The
IDs of settings defined in [RFC7540] have been reserved for IDs of settings defined in [RFC7540] have been reserved for
simplicity. See Section 10.4. simplicity. See Section 10.4.
A.4. HTTP/2 Error Codes A.4. HTTP/2 Error Codes
QUIC has the same concepts of "stream" and "connection" errors that QUIC has the same concepts of "stream" and "connection" errors that
HTTP/2 provides. However, there is no direct portability of HTTP/2 HTTP/2 provides. However, there is no direct portability of HTTP/2
error codes. error codes.
The HTTP/2 error codes defined in Section 7 of [RFC7540] map to the The HTTP/2 error codes defined in Section 7 of [RFC7540] map to the
HTTP/QUIC error codes as follows: HTTP/3 error codes as follows:
NO_ERROR (0x0): HTTP_NO_ERROR in Section 8.1. NO_ERROR (0x0): HTTP_NO_ERROR in Section 8.1.
PROTOCOL_ERROR (0x1): No single mapping. See new PROTOCOL_ERROR (0x1): No single mapping. See new
HTTP_MALFORMED_FRAME error codes defined in Section 8.1. HTTP_MALFORMED_FRAME error codes defined in Section 8.1.
INTERNAL_ERROR (0x2): HTTP_INTERNAL_ERROR in Section 8.1. INTERNAL_ERROR (0x2): HTTP_INTERNAL_ERROR in Section 8.1.
FLOW_CONTROL_ERROR (0x3): Not applicable, since QUIC handles flow FLOW_CONTROL_ERROR (0x3): Not applicable, since QUIC handles flow
control. Would provoke a QUIC_FLOW_CONTROL_RECEIVED_TOO_MUCH_DATA control. Would provoke a QUIC_FLOW_CONTROL_RECEIVED_TOO_MUCH_DATA
skipping to change at page 44, line 22 skipping to change at page 46, line 38
CONNECT_ERROR (0xa): HTTP_CONNECT_ERROR in Section 8.1. CONNECT_ERROR (0xa): HTTP_CONNECT_ERROR in Section 8.1.
ENHANCE_YOUR_CALM (0xb): HTTP_EXCESSIVE_LOAD in Section 8.1. ENHANCE_YOUR_CALM (0xb): HTTP_EXCESSIVE_LOAD in Section 8.1.
INADEQUATE_SECURITY (0xc): Not applicable, since QUIC is assumed to INADEQUATE_SECURITY (0xc): Not applicable, since QUIC is assumed to
provide sufficient security on all connections. provide sufficient security on all connections.
HTTP_1_1_REQUIRED (0xd): HTTP_VERSION_FALLBACK in Section 8.1. HTTP_1_1_REQUIRED (0xd): HTTP_VERSION_FALLBACK in Section 8.1.
Error codes need to be defined for HTTP/2 and HTTP/QUIC separately. Error codes need to be defined for HTTP/2 and HTTP/3 separately. See
See Section 10.5. Section 10.5.
Appendix B. Change Log Appendix B. Change Log
*RFC Editor's Note:* Please remove this section prior to *RFC Editor's Note:* Please remove this section prior to
publication of a final version of this document. publication of a final version of this document.
B.1. Since draft-ietf-quic-http-15 B.1. Since draft-ietf-quic-http-16
o Rename "HTTP/QUIC" to "HTTP/3" (#1973)
o Changes to PRIORITY frame (#1865, #2075)
* Permitted as first frame of request streams
* Remove exclusive reprioritization
* Changes to Prioritized Element Type bits
o Define DUPLICATE_PUSH frame to refer to another PUSH_PROMISE
(#2072)
o Set defaults for settings, allow request before receiving SETTINGS
(#1809, #1846, #2038)
o Clarify message processing rules for streams that aren't closed
(#1972, #2003)
o Removed reservation of error code 0 and moved HTTP_NO_ERROR to
this value (#1922)
o Removed prohibition of zero-length DATA frames (#2098)
B.2. Since draft-ietf-quic-http-15
Substantial editorial reorganization; no technical changes. Substantial editorial reorganization; no technical changes.
B.2. Since draft-ietf-quic-http-14 B.3. Since draft-ietf-quic-http-14
o Recommend sensible values for QUIC transport parameters o Recommend sensible values for QUIC transport parameters
(#1720,#1806) (#1720,#1806)
o Define error for missing SETTINGS frame (#1697,#1808) o Define error for missing SETTINGS frame (#1697,#1808)
o Setting values are variable-length integers (#1556,#1807) and do o Setting values are variable-length integers (#1556,#1807) and do
not have separate maximum values (#1820) not have separate maximum values (#1820)
o Expanded discussion of connection closure (#1599,#1717,#1712) o Expanded discussion of connection closure (#1599,#1717,#1712)
o HTTP_VERSION_FALLBACK falls back to HTTP/1.1 (#1677,#1685) o HTTP_VERSION_FALLBACK falls back to HTTP/1.1 (#1677,#1685)
B.3. Since draft-ietf-quic-http-13 B.4. Since draft-ietf-quic-http-13
o Reserved some frame types for grease (#1333, #1446) o Reserved some frame types for grease (#1333, #1446)
o Unknown unidirectional stream types are tolerated, not errors; o Unknown unidirectional stream types are tolerated, not errors;
some reserved for grease (#1490, #1525) some reserved for grease (#1490, #1525)
o Require settings to be remembered for 0-RTT, prohibit reductions o Require settings to be remembered for 0-RTT, prohibit reductions
(#1541, #1641) (#1541, #1641)
o Specify behavior for truncated requests (#1596, #1643) o Specify behavior for truncated requests (#1596, #1643)
B.4. Since draft-ietf-quic-http-12 B.5. Since draft-ietf-quic-http-12
o TLS SNI extension isn't mandatory if an alternative method is used o TLS SNI extension isn't mandatory if an alternative method is used
(#1459, #1462, #1466) (#1459, #1462, #1466)
o Removed flags from HTTP/QUIC frames (#1388, #1398) o Removed flags from HTTP/3 frames (#1388, #1398)
o Reserved frame types and settings for use in preserving o Reserved frame types and settings for use in preserving
extensibility (#1333, #1446) extensibility (#1333, #1446)
o Added general error code (#1391, #1397) o Added general error code (#1391, #1397)
o Unidirectional streams carry a type byte and are extensible o Unidirectional streams carry a type byte and are extensible
(#910,#1359) (#910,#1359)
o Priority mechanism now uses explicit placeholders to enable o Priority mechanism now uses explicit placeholders to enable
persistent structure in the tree (#441,#1421,#1422) persistent structure in the tree (#441,#1421,#1422)
B.5. Since draft-ietf-quic-http-11 B.6. Since draft-ietf-quic-http-11
o Moved QPACK table updates and acknowledgments to dedicated streams o Moved QPACK table updates and acknowledgments to dedicated streams
(#1121, #1122, #1238) (#1121, #1122, #1238)
B.6. Since draft-ietf-quic-http-10 B.7. Since draft-ietf-quic-http-10
o Settings need to be remembered when attempting and accepting 0-RTT o Settings need to be remembered when attempting and accepting 0-RTT
(#1157, #1207) (#1157, #1207)
B.7. Since draft-ietf-quic-http-09 B.8. Since draft-ietf-quic-http-09
o Selected QCRAM for header compression (#228, #1117) o Selected QCRAM for header compression (#228, #1117)
o The server_name TLS extension is now mandatory (#296, #495) o The server_name TLS extension is now mandatory (#296, #495)
o Specified handling of unsupported versions in Alt-Svc (#1093, o Specified handling of unsupported versions in Alt-Svc (#1093,
#1097) #1097)
B.8. Since draft-ietf-quic-http-08 B.9. Since draft-ietf-quic-http-08
o Clarified connection coalescing rules (#940, #1024) o Clarified connection coalescing rules (#940, #1024)
B.9. Since draft-ietf-quic-http-07 B.10. Since draft-ietf-quic-http-07
o Changes for integer encodings in QUIC (#595,#905) o Changes for integer encodings in QUIC (#595,#905)
o Use unidirectional streams as appropriate (#515, #240, #281, #886) o Use unidirectional streams as appropriate (#515, #240, #281, #886)
o Improvement to the description of GOAWAY (#604, #898) o Improvement to the description of GOAWAY (#604, #898)
o Improve description of server push usage (#947, #950, #957) o Improve description of server push usage (#947, #950, #957)
B.10. Since draft-ietf-quic-http-06 B.11. Since draft-ietf-quic-http-06
o Track changes in QUIC error code usage (#485) o Track changes in QUIC error code usage (#485)
B.11. Since draft-ietf-quic-http-05 B.12. Since draft-ietf-quic-http-05
o Made push ID sequential, add MAX_PUSH_ID, remove o Made push ID sequential, add MAX_PUSH_ID, remove
SETTINGS_ENABLE_PUSH (#709) SETTINGS_ENABLE_PUSH (#709)
o Guidance about keep-alive and QUIC PINGs (#729) o Guidance about keep-alive and QUIC PINGs (#729)
o Expanded text on GOAWAY and cancellation (#757) o Expanded text on GOAWAY and cancellation (#757)
B.12. Since draft-ietf-quic-http-04 B.13. Since draft-ietf-quic-http-04
o Cite RFC 5234 (#404) o Cite RFC 5234 (#404)
o Return to a single stream per request (#245,#557) o Return to a single stream per request (#245,#557)
o Use separate frame type and settings registries from HTTP/2 (#81) o Use separate frame type and settings registries from HTTP/2 (#81)
o SETTINGS_ENABLE_PUSH instead of SETTINGS_DISABLE_PUSH (#477) o SETTINGS_ENABLE_PUSH instead of SETTINGS_DISABLE_PUSH (#477)
o Restored GOAWAY (#696) o Restored GOAWAY (#696)
o Identify server push using Push ID rather than a stream ID o Identify server push using Push ID rather than a stream ID
(#702,#281) (#702,#281)
o DATA frames cannot be empty (#700) o DATA frames cannot be empty (#700)
B.13. Since draft-ietf-quic-http-03 B.14. Since draft-ietf-quic-http-03
None. None.
B.14. Since draft-ietf-quic-http-02 B.15. Since draft-ietf-quic-http-02
o Track changes in transport draft o Track changes in transport draft
B.15. Since draft-ietf-quic-http-01 B.16. Since draft-ietf-quic-http-01
o SETTINGS changes (#181): o SETTINGS changes (#181):
* SETTINGS can be sent only once at the start of a connection; no * SETTINGS can be sent only once at the start of a connection; no
changes thereafter changes thereafter
* SETTINGS_ACK removed * SETTINGS_ACK removed
* Settings can only occur in the SETTINGS frame a single time * Settings can only occur in the SETTINGS frame a single time
* Boolean format updated * Boolean format updated
o Alt-Svc parameter changed from "v" to "quic"; format updated o Alt-Svc parameter changed from "v" to "quic"; format updated
(#229) (#229)
o Closing the connection control stream or any message control o Closing the connection control stream or any message control
stream is a fatal error (#176) stream is a fatal error (#176)
o HPACK Sequence counter can wrap (#173) o HPACK Sequence counter can wrap (#173)
o 0-RTT guidance added o 0-RTT guidance added
o Guide to differences from HTTP/2 and porting HTTP/2 extensions o Guide to differences from HTTP/2 and porting HTTP/2 extensions
added (#127,#242) added (#127,#242)
B.16. Since draft-ietf-quic-http-00 B.17. Since draft-ietf-quic-http-00
o Changed "HTTP/2-over-QUIC" to "HTTP/QUIC" throughout (#11,#29) o Changed "HTTP/2-over-QUIC" to "HTTP/QUIC" throughout (#11,#29)
o Changed from using HTTP/2 framing within Stream 3 to new framing o Changed from using HTTP/2 framing within Stream 3 to new framing
format and two-stream-per-request model (#71,#72,#73) format and two-stream-per-request model (#71,#72,#73)
o Adopted SETTINGS format from draft-bishop-httpbis-extended- o Adopted SETTINGS format from draft-bishop-httpbis-extended-
settings-01 settings-01
o Reworked SETTINGS_ACK to account for indeterminate inter-stream o Reworked SETTINGS_ACK to account for indeterminate inter-stream
skipping to change at page 48, line 4 skipping to change at page 50, line 35
o Changed from using HTTP/2 framing within Stream 3 to new framing o Changed from using HTTP/2 framing within Stream 3 to new framing
format and two-stream-per-request model (#71,#72,#73) format and two-stream-per-request model (#71,#72,#73)
o Adopted SETTINGS format from draft-bishop-httpbis-extended- o Adopted SETTINGS format from draft-bishop-httpbis-extended-
settings-01 settings-01
o Reworked SETTINGS_ACK to account for indeterminate inter-stream o Reworked SETTINGS_ACK to account for indeterminate inter-stream
order (#75) order (#75)
o Described CONNECT pseudo-method (#95) o Described CONNECT pseudo-method (#95)
o Updated ALPN token and Alt-Svc guidance (#13,#87) o Updated ALPN token and Alt-Svc guidance (#13,#87)
o Application-layer-defined error codes (#19,#74) o Application-layer-defined error codes (#19,#74)
B.17. Since draft-shade-quic-http2-mapping-00 B.18. Since draft-shade-quic-http2-mapping-00
o Adopted as base for draft-ietf-quic-http o Adopted as base for draft-ietf-quic-http
o Updated authors/editors list o Updated authors/editors list
Acknowledgements Acknowledgements
The original authors of this specification were Robbie Shade and Mike The original authors of this specification were Robbie Shade and Mike
Warres. Warres.
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