QPACK: Header Compression for HTTP over QUIC
draft-ietf-quic-qpack-02
QUIC C. Krasic
Internet-Draft Netflix
Intended status: Standards Track M. Bishop
Expires: February 16, 2019 Akamai Technologies
A. Frindell, Ed.
Facebook
August 15, 2018
QPACK: Header Compression for HTTP over QUIC
draft-ietf-quic-qpack-02
Abstract
This specification defines QPACK, a compression format for
efficiently representing HTTP header fields, to be used in HTTP over
QUIC. This is a variation of HPACK header compression that seeks to
reduce head-of-line blocking.
Note to Readers
Discussion of this draft takes place on the QUIC working group
mailing list (quic@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/search/?email_list=quic [1].
Working Group information can be found at https://github.com/quicwg
[2]; source code and issues list for this draft can be found at
https://github.com/quicwg/base-drafts/labels/-qpack [3].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on February 16, 2019.
Krasic, et al. Expires February 16, 2019 [Page 1]
Internet-Draft QPACK August 2018
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Header Tables . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Static Table . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Dynamic Table . . . . . . . . . . . . . . . . . . . . . . 4
2.2.1. Absolute and Relative Indexing . . . . . . . . . . . 5
2.2.2. Post-Base Indexing . . . . . . . . . . . . . . . . . 6
2.3. Avoiding Head-of-Line Blocking in HTTP/QUIC . . . . . . . 7
2.3.1. State Synchronization . . . . . . . . . . . . . . . . 8
3. Conventions and Definitions . . . . . . . . . . . . . . . . . 9
3.1. Notational Conventions . . . . . . . . . . . . . . . . . 9
4. Configuration . . . . . . . . . . . . . . . . . . . . . . . . 9
5. Wire Format . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1. Primitives . . . . . . . . . . . . . . . . . . . . . . . 10
5.1.1. Prefixed Integers . . . . . . . . . . . . . . . . . . 10
5.1.2. String Literals . . . . . . . . . . . . . . . . . . . 10
5.2. QPACK Encoder Stream . . . . . . . . . . . . . . . . . . 11
5.2.1. Insert With Name Reference . . . . . . . . . . . . . 11
5.2.2. Insert Without Name Reference . . . . . . . . . . . . 12
5.2.3. Duplicate . . . . . . . . . . . . . . . . . . . . . . 12
5.2.4. Dynamic Table Size Update . . . . . . . . . . . . . . 13
5.3. QPACK Decoder Stream . . . . . . . . . . . . . . . . . . 13
5.3.1. Table State Synchronize . . . . . . . . . . . . . . . 13
5.3.2. Header Acknowledgement . . . . . . . . . . . . . . . 14
5.3.3. Stream Cancellation . . . . . . . . . . . . . . . . . 15
5.4. Request and Push Streams . . . . . . . . . . . . . . . . 15
5.4.1. Header Data Prefix . . . . . . . . . . . . . . . . . 15
5.4.2. Instructions . . . . . . . . . . . . . . . . . . . . 17
6. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 19
7. Encoding Strategies . . . . . . . . . . . . . . . . . . . . . 20
7.1. Single Pass Encoding . . . . . . . . . . . . . . . . . . 20
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