draft-ietf-quic-http-01.txt		draft-ietf-quic-http-02.txt
	QUIC M. Bishop, Ed.		QUIC M. Bishop, Ed.
	Internet-Draft Microsoft		Internet-Draft Microsoft
	Intended status: Standards Track January 14, 2017		Intended status: Standards Track March 13, 2017
	Expires: July 18, 2017		Expires: September 14, 2017
	Hypertext Transfer Protocol (HTTP) over QUIC		Hypertext Transfer Protocol (HTTP) over QUIC
	draft-ietf-quic-http-01		draft-ietf-quic-http-02
	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. Specifically, this		describes a mapping of HTTP semantics over QUIC. This document also
	document identifies HTTP/2 features that are subsumed by QUIC, and		identifies HTTP/2 features that are subsumed by QUIC, and describes
	describes how the other features can be implemented atop QUIC.		how HTTP/2 extensions can be ported to QUIC.
	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 .		https://mailarchive.ietf.org/arch/search/?email_list=quic .
	Working Group information can be found at https://github.com/quicwg ;		Working Group information can be found at https://github.com/quicwg ;
	source code and issues list for this draft can be found at		source code and issues list for this draft can be found at
	https://github.com/quicwg/base-drafts/labels/http .		https://github.com/quicwg/base-drafts/labels/http .
	skipping to change at page 1, line 45 ¶		skipping to change at page 1, line 45 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	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 July 18, 2017.		This Internet-Draft will expire on September 14, 2017.
	Copyright Notice		Copyright Notice
	Copyright (c) 2017 IETF Trust and the persons identified as the		Copyright (c) 2017 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
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://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
	skipping to change at page 2, line 34 ¶		skipping to change at page 2, line 34 ¶
	2. QUIC Advertisement . . . . . . . . . . . . . . . . . . . . . 3		2. QUIC Advertisement . . . . . . . . . . . . . . . . . . . . . 3
	2.1. QUIC Version Hints . . . . . . . . . . . . . . . . . . . 4		2.1. QUIC Version Hints . . . . . . . . . . . . . . . . . . . 4
	3. Connection Establishment . . . . . . . . . . . . . . . . . . 4		3. Connection Establishment . . . . . . . . . . . . . . . . . . 4
	3.1. Draft Version Identification . . . . . . . . . . . . . . 5		3.1. Draft Version Identification . . . . . . . . . . . . . . 5
	4. Stream Mapping and Usage . . . . . . . . . . . . . . . . . . 5		4. Stream Mapping and Usage . . . . . . . . . . . . . . . . . . 5
	4.1. Stream 3: Connection Control Stream . . . . . . . . . . . 6		4.1. Stream 3: Connection Control Stream . . . . . . . . . . . 6
	4.2. HTTP Message Exchanges . . . . . . . . . . . . . . . . . 6		4.2. HTTP Message Exchanges . . . . . . . . . . . . . . . . . 6
	4.2.1. Header Compression . . . . . . . . . . . . . . . . . 7		4.2.1. Header Compression . . . . . . . . . . . . . . . . . 7
	4.2.2. The CONNECT Method . . . . . . . . . . . . . . . . . 8		4.2.2. The CONNECT Method . . . . . . . . . . . . . . . . . 8
	4.3. Stream Priorities . . . . . . . . . . . . . . . . . . . . 9		4.3. Stream Priorities . . . . . . . . . . . . . . . . . . . . 9
	4.4. Flow Control . . . . . . . . . . . . . . . . . . . . . . 9		4.4. Server Push . . . . . . . . . . . . . . . . . . . . . . . 9
	4.5. Server Push . . . . . . . . . . . . . . . . . . . . . . . 9
	5. HTTP Framing Layer . . . . . . . . . . . . . . . . . . . . . 10		5. HTTP Framing Layer . . . . . . . . . . . . . . . . . . . . . 10
	5.1. Frame Layout . . . . . . . . . . . . . . . . . . . . . . 10		5.1. Frame Layout . . . . . . . . . . . . . . . . . . . . . . 10
	5.2. Frame Definitions . . . . . . . . . . . . . . . . . . . . 11		5.2. Frame Definitions . . . . . . . . . . . . . . . . . . . . 10
	5.2.1. DATA . . . . . . . . . . . . . . . . . . . . . . . . 11		5.2.1. HEADERS . . . . . . . . . . . . . . . . . . . . . . . 10
	5.2.2. HEADERS . . . . . . . . . . . . . . . . . . . . . . . 11		5.2.2. PRIORITY . . . . . . . . . . . . . . . . . . . . . . 11
	5.2.3. PRIORITY . . . . . . . . . . . . . . . . . . . . . . 12		5.2.3. SETTINGS . . . . . . . . . . . . . . . . . . . . . . 12
	5.2.4. RST_STREAM . . . . . . . . . . . . . . . . . . . . . 13		5.2.4. PUSH_PROMISE . . . . . . . . . . . . . . . . . . . . 15
	5.2.5. SETTINGS . . . . . . . . . . . . . . . . . . . . . . 13		6. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 15
	5.2.6. PUSH_PROMISE . . . . . . . . . . . . . . . . . . . . 16		6.1. HTTP-Defined QUIC Error Codes . . . . . . . . . . . . . . 16
	5.2.7. PING . . . . . . . . . . . . . . . . . . . . . . . . 17		7. Considerations for Transitioning from HTTP/2 . . . . . . . . 17
	5.2.8. GOAWAY frame . . . . . . . . . . . . . . . . . . . . 17		7.1. HTTP Frame Types . . . . . . . . . . . . . . . . . . . . 17
	5.2.9. WINDOW_UPDATE frame . . . . . . . . . . . . . . . . . 17		7.2. HTTP/2 SETTINGS Parameters . . . . . . . . . . . . . . . 18
	5.2.10. CONTINUATION frame . . . . . . . . . . . . . . . . . 17		7.3. HTTP/2 Error Codes . . . . . . . . . . . . . . . . . . . 19
	5.2.11. SETTINGS_ACK Frame . . . . . . . . . . . . . . . . . 18		8. Security Considerations . . . . . . . . . . . . . . . . . . . 20
	6. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 19		9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21
	6.1. HTTP-Defined QUIC Error Codes . . . . . . . . . . . . . . 19		9.1. Registration of HTTP/QUIC Identification String . . . . . 21
	6.2. Mapping HTTP/2 Error Codes . . . . . . . . . . . . . . . 20		9.2. Registration of QUIC Version Hint Alt-Svc Parameter . . . 21
			9.3. Existing Frame Types . . . . . . . . . . . . . . . . . . 21
	7. Security Considerations . . . . . . . . . . . . . . . . . . . 21		9.4. Settings Parameters . . . . . . . . . . . . . . . . . . . 22
	8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21		9.5. Error Codes . . . . . . . . . . . . . . . . . . . . . . . 23
	8.1. Registration of HTTP/QUIC Identification String . . . . . 21		10. References . . . . . . . . . . . . . . . . . . . . . . . . . 25
	8.2. Registration of Version Hint Alt-Svc Parameter . . . . . 21		10.1. Normative References . . . . . . . . . . . . . . . . . . 25
	8.3. Existing Frame Types . . . . . . . . . . . . . . . . . . 22		10.2. Informative References . . . . . . . . . . . . . . . . . 26
	8.4. New Frame Types . . . . . . . . . . . . . . . . . . . . . 23		Appendix A. Contributors . . . . . . . . . . . . . . . . . . . . 26
	9. References . . . . . . . . . . . . . . . . . . . . . . . . . 23		Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 26
	9.1. Normative References . . . . . . . . . . . . . . . . . . 23		B.1. Since draft-ietf-quic-http-01: . . . . . . . . . . . . . 26
	9.2. Informative References . . . . . . . . . . . . . . . . . 24		B.2. Since draft-ietf-quic-http-00: . . . . . . . . . . . . . 27
	Appendix A. Contributors . . . . . . . . . . . . . . . . . . . . 24		B.3. Since draft-shade-quic-http2-mapping-00: . . . . . . . . 27
	Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 24		Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 27
	B.1. Since draft-ietf-quic-http-00: . . . . . . . . . . . . . 24
	B.2. Since draft-shade-quic-http2-mapping-00: . . . . . . . . 25
	Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 25
	1. Introduction		1. Introduction
	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, drawing heavily on		describes a mapping of HTTP semantics over QUIC, drawing heavily on
	the existing TCP mapping, HTTP/2. Specifically, this document		the existing TCP mapping, HTTP/2. Specifically, this document
	identifies HTTP/2 features that are subsumed by QUIC, and describes		identifies HTTP/2 features that are subsumed by QUIC, and describes
	how the other features can be implemented atop QUIC.		how the other features can be implemented atop QUIC.
	skipping to change at page 3, line 41 ¶		skipping to change at page 3, line 37 ¶
	HTTP/2, see [RFC7540].		HTTP/2, see [RFC7540].
	1.1. Notational Conventions		1.1. Notational Conventions
	The words "MUST", "MUST NOT", "SHOULD", and "MAY" are used in this		The words "MUST", "MUST NOT", "SHOULD", and "MAY" are used in this
	document. It's not shouting; when they are capitalized, they have		document. It's not shouting; when they are capitalized, they have
	the special meaning defined in [RFC2119].		the special meaning defined in [RFC2119].
	2. QUIC Advertisement		2. QUIC Advertisement
	A server advertises that it can speak HTTP/QUIC via the Alt-Svc		An HTTP origin advertises the availability of an equivalent HTTP/QUIC
	([RFC7838]) HTTP response header (or the semantically equivalent Alt-		endpoint via the Alt-Svc HTTP response header or the HTTP/2 ALTSVC
	Svc HTTP/2 Extension Frame Type), using the ALPN token defined in		frame ([RFC7838]), using the ALPN token defined in Section 3.
	Section 3.
	Thus, a server could indicate in an HTTP/1.1 or HTTP/2 response that		For example, an origin could indicate in an HTTP/1.1 or HTTP/2
	HTTP/QUIC was available on UDP port 443 by including the following		response that HTTP/QUIC was available on UDP port 443 at the same
	header in any response:		hostname by including the following header in any response:
	Alt-Svc: hq=":443"		Alt-Svc: hq=":443"
			On receipt of an Alt-Svc header indicating HTTP/QUIC support, a
			client MAY attempt to establish a QUIC connection to the indicated
			host and port and, if successful, send HTTP requests using the
			mapping described in this document.
			Connectivity problems (e.g. firewall blocking UDP) can result in QUIC
			connection establishment failure, in which case the client SHOULD
			continue using the existing connection or try another alternative
			endpoint offered by the origin.
	2.1. QUIC Version Hints		2.1. QUIC Version Hints
	This document defines the "v" parameter for Alt-Svc, which is used to		This document defines the "quic" parameter for Alt-Svc, which MAY be
	provide version-negotiation hints to HTTP/QUIC clients. Syntax:		used to provide version-negotiation hints to HTTP/QUIC clients. QUIC
			versions are four-octet sequences with no additional constraints on
			format. Syntax:
	v = version		quic = version-number
	version = DQUOTE ( "c" version-string / "x" version-number ) DQUOTE		version-number = 1*8HEXDIG; hex-encoded QUIC version
	version-string = token; percent-encoded QUIC version
	version-number = 1*8 HEXDIG; hex-encoded QUIC version
	When multiple versions are supported, the "v" parameter MAY be		Leading zeros SHOULD be omitted for brevity. When multiple versions
	repeated multiple times in a single Alt-Svc entry. For example, if a		are supported, the "quic" parameter MAY be repeated multiple times in
	server supported both version "Q034" and version 0x00000001, it would		a single Alt-Svc entry. For example, if a server supported both
	specify the following header:		version 0x00000001 and the version rendered in ASCII as "Q034", it
			could specify the following header:
	Alt-Svc: hq=":443";v="x1";v="cQ034"		Alt-Svc: hq=":443";quic=1;quic=51303334
	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).		preferred version). Origins SHOULD list only versions which are
			supported by the alternative, but MAY omit supported versions for any
	QUIC versions are four-octet sequences with no additional constraints		reason.
	on format. Versions containing octets not allowed in tokens
	([RFC7230], Section 3.2.6) MUST be encoded using the hexidecimal
	representation. Versions containing only octets allowed in tokens
	MAY be encoded using either representation.
	On receipt of an Alt-Svc header indicating QUIC support, a client MAY
	attempt to establish a QUIC connection on the indicated port and, if
	successful, send HTTP requests using the mapping described in this
	document. Servers SHOULD list only versions which they support, but
	MAY omit supported versions for any reason.
	Connectivity problems (e.g. firewall blocking UDP) may result in QUIC
	connection establishment failure, in which case the client should
	gracefully fall back to HTTP/2.
	3. Connection Establishment		3. Connection Establishment
	HTTP/QUIC connections are established as described in		HTTP/QUIC connections are established as described in
	[QUIC-TRANSPORT]. During connection establishment, HTTP/QUIC support		[QUIC-TRANSPORT]. During connection establishment, HTTP/QUIC support
	is indicated by selecting the ALPN token "hq" in the crypto		is indicated by selecting the ALPN token "hq" in the crypto
	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-specific settings are		are set in the initial crypto handshake, HTTP-specific settings 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 5.2.5) MUST be sent as the		established, a SETTINGS frame (Section 5.2.3) MUST be sent as the
	initial frame of the HTTP control stream (StreamID 3, see Section 4).		initial frame of the HTTP control stream (StreamID 3, see Section 4).
			The server MUST NOT send data on any other stream until the client's
			SETTINGS frame has been received.
	3.1. Draft Version Identification		3.1. 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.
	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 "hq". Until such an RFC exists, implementations MUST
	NOT identify themselves using these strings.		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 "hq-
	01".		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
	skipping to change at page 5, line 41 ¶		skipping to change at page 5, line 39 ¶
	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. A QUIC receiver		this framing is invisible to the HTTP framing layer. A QUIC receiver
	buffers and orders received STREAM frames, exposing the data		buffers and orders received STREAM frames, exposing the data
	contained within as a reliable byte stream to the application.		contained within as a reliable byte stream to the application.
	QUIC reserves Stream 1 for crypto operations (the handshake, crypto		QUIC reserves Stream 1 for crypto operations (the handshake, crypto
	config updates). Stream 3 is reserved for sending and receiving HTTP		config updates). Stream 3 is reserved for sending and receiving HTTP
	control frames, and is analogous to HTTP/2's Stream 0.		control frames, and is analogous to HTTP/2's Stream 0. This
			connection control stream is considered critical to the HTTP
			connection. If the connection control stream is closed for any
			reason, this MUST be treated as a connection error of type
			QUIC_CLOSED_CRITICAL_STREAM.
	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. An HTTP request/response consumes a		most of the stream management. An HTTP request/response consumes a
	pair of streams: This means that the client's first request occurs on		pair of streams: This means that the client's first request occurs on
	QUIC streams 5 and 7, the second on stream 9 and 11, and so on. The		QUIC streams 5 and 7, the second on stream 9 and 11, and so on. The
	server's first push consumes streams 2 and 4. This amounts to the		server's first push consumes streams 2 and 4. This amounts to the
	second least-significant bit differentiating the two streams in a		second least-significant bit differentiating the two streams in a
	request.		request.
	The lower-numbered stream is called the message control stream and		The lower-numbered stream is called the message control stream and
	carries frames related to the request/response, including HEADERS.		carries frames related to the request/response, including HEADERS.
	All request control streams are exempt from connection-level flow		The higher-numbered stream is the data stream and carries the
	control. The higher-numbered stream is the data stream and carries		request/response body with no additional framing. Note that a
	the request/response body with no additional framing. Note that a
	request or response without a body will cause this stream to be half-		request or response without a body will cause this stream to be half-
	closed in the corresponding direction without transferring data.		closed in the corresponding direction without transferring data.
			Because the message control stream contains HPACK data which
			manipulates connection-level state, the message control stream MUST
			NOT be closed with a stream-level error. If an implementation
			chooses to reject a request with a QUIC error code, it MUST trigger a
			QUIC RST_STREAM on the data stream only. An implementation MAY close
			(FIN) a message control stream without completing a full HTTP message
			if the data stream has been abruptly closed. Data on message control
			streams MUST be fully consumed, or the connection terminated.
			All message control streams are considered critical to the HTTP
			connection. If a message control stream is terminated abruptly for
			any reason, this MUST be treated as a connection error of type
			HTTP_RST_CONTROL_STREAM. When a message control stream terminates
			cleanly, if the last frame on the stream was truncated, this MUST be
			treated as a connection error (see HTTP_MALFORMED_* in Section 6.1).
	Pairs of streams must be utilized sequentially, with no gaps. The		Pairs of streams must be utilized sequentially, with no gaps. The
	data stream MUST be reserved with the QUIC implementation when the		data stream is opened at the same time as the message control stream
	message control stream is opened or reserved, and MUST be closed		is opened and is closed after transferring the body. The data stream
	after transferring the body, or else closed immediately after sending		is closed immediately after sending the request headers if there is
	the request headers if there is no body.		no body.
	HTTP does not need to do any separate multiplexing when using QUIC -		HTTP does not need to do any separate multiplexing when using QUIC -
	data sent over a QUIC stream always maps to a particular HTTP		data sent over a QUIC stream always maps to a particular HTTP
	transaction. Requests and responses are considered complete when the		transaction. Requests and responses are considered complete when the
	corresponding QUIC streams are closed in the appropriate direction.		corresponding QUIC streams are closed in the appropriate direction.
	4.1. Stream 3: Connection Control Stream		4.1. Stream 3: Connection Control Stream
	Since most connection-level concerns from HTTP/2 will be managed by		Since most connection-level concerns will be managed by QUIC, the
	QUIC, the primary use of Stream 3 will be for SETTINGS and PRIORITY		primary use of Stream 3 will be for the SETTINGS frame when the
	frames. Stream 3 is exempt from connection-level flow-control.		connection opens and for PRIORITY frames subsequently.
	4.2. HTTP Message Exchanges		4.2. HTTP Message Exchanges
	A client sends an HTTP request on a new pair of QUIC streams. A		A client sends an HTTP request on a new pair of QUIC streams. A
	server sends an HTTP response on the same streams as the request.		server sends an HTTP response on the same streams as the request.
	An HTTP message (request or response) consists of:		An HTTP message (request or response) consists of:
	1. for a response only, zero or more header blocks (a sequence of		1. one header block (see Section 5.2.1) on the control stream
	HEADERS frames with End Header Block set on the last) on the		containing the message headers (see [RFC7230], Section 3.2),
	control stream containing the message headers of informational
	(1xx) HTTP responses (see [RFC7230], Section 3.2 and [RFC7231],
	Section 6.2),
	2. one header block on the control stream containing the message
	headers (see [RFC7230], Section 3.2),
	3. the payload body (see [RFC7230], Section 3.3), sent on the data		2. the payload body (see [RFC7230], Section 3.3), sent on the data
	stream,		stream,
	4. optionally, one header block on the control stream containing the		3. optionally, one header block on the control stream containing the
	trailer-part, if present (see [RFC7230], Section 4.1.2).		trailer-part, if present (see [RFC7230], Section 4.1.2).
			In addition, prior to sending the message header block indicated
			above, a response may contain zero or more header blocks on the
			control stream containing the message headers of informational (1xx)
			HTTP responses (see [RFC7230], Section 3.2 and [RFC7231],
			Section 6.2).
	The data stream MUST be half-closed immediately after the transfer of		The data stream MUST be half-closed immediately after the transfer of
	the body. If the message does not contain a body, the corresponding		the body. If the message does not contain a body, the corresponding
	data stream MUST still be half-closed without transferring any data.		data stream MUST still be half-closed without transferring any data.
	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 a header block following the		Trailing header fields are carried in an additional header block on
	body. Such a header block is a sequence of HEADERS frames with End		the message control stream. Such a header block is a sequence of
	Header Block set on the last frame. Header blocks after the first		HEADERS frames with End Header Block set on the last frame. Senders
	but before the end of the stream are invalid. These MUST be decoded		MUST send only one header block in the trailers section; receivers
	to maintain HPACK decoder state, but the resulting output MUST be		MUST decode any subsequent header blocks in order to maintain HPACK
	discarded.		decoder state, but the resulting output MUST be discarded.
	An HTTP request/response exchange fully consumes a pair of streams.		An HTTP request/response exchange fully consumes a pair of streams.
	After sending a request, a client closes the streams for sending;		After sending a request, a client closes the streams for sending;
	after sending a response, the server closes its streams for sending		after sending a response, the server closes its streams for sending
	and the QUIC streams are fully closed.		and the QUIC streams are fully closed.
	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 sending a RST_STREAM with an error code of NO_ERROR		without error by sending a RST_STREAM with an error code of NO_ERROR
	after sending a complete response and closing its stream. Clients		after sending a complete response and closing its stream. Clients
	MUST NOT discard responses as a result of receiving such a		MUST NOT discard responses as a result of receiving such a
	RST_STREAM, though clients can always discard responses at their		RST_STREAM, though clients can always discard responses at their
	discretion for other reasons.		discretion for other reasons.
	4.2.1. Header Compression		4.2.1. Header Compression
	HTTP/QUIC uses HPACK header compression as described in [RFC7541].		HTTP/QUIC uses HPACK header compression as described in [RFC7541].
	HPACK was designed for HTTP/2 with the assumption of in- order		HPACK was designed for HTTP/2 with the assumption of in-order
	delivery such as that provided by TCP. A sequence of encoded header		delivery such as that provided by TCP. A sequence of encoded header
	blocks must arrive (and be decoded) at an endpoint in the same order		blocks must arrive (and be decoded) at an endpoint in the same order
	in which they were encoded. This ensures that the dynamic state at		in which they were encoded. This ensures that the dynamic state at
	the two endpoints remains in sync.		the two endpoints remains in sync.
	QUIC streams provide in-order delivery of data sent on those streams,		QUIC streams provide in-order delivery of data sent on those streams,
	but there are no guarantees about order of delivery between streams.		but there are no guarantees about order of delivery between streams.
	To achieve in-order delivery of HEADERS frames in QUIC, the HPACK-		To achieve in-order delivery of HEADERS frames in QUIC, the HPACK-
	bearing frames contain a counter which can be used to ensure in-order		bearing frames contain a counter which can be used to ensure in-order
	processing. Data (request/response bodies) which arrive out of order		processing. Data (request/response bodies) which arrive out of order
	skipping to change at page 9, line 16 ¶		skipping to change at page 9, line 32 ¶
	4.3. Stream Priorities		4.3. Stream Priorities
	HTTP/QUIC uses the priority scheme described in [RFC7540]		HTTP/QUIC uses the priority scheme described in [RFC7540]
	Section 5.3. In this priority scheme, a given stream can be		Section 5.3. In this priority scheme, a given stream can be
	designated as dependent upon another stream, which expresses the		designated as dependent upon another stream, which expresses the
	preference that the latter stream (the "parent" stream) be allocated		preference that the latter stream (the "parent" stream) be allocated
	resources before the former stream (the "dependent" stream). Taken		resources before the former stream (the "dependent" stream). Taken
	together, the dependencies across all streams in a connection form a		together, the dependencies across all streams in a connection form a
	dependency tree. The structure of the dependency tree changes as		dependency tree. The structure of the dependency tree changes as
	HEADERS and PRIORITY frames add, remove, or change the dependency		PRIORITY frames add, remove, or change the dependency links between
	links between streams.		streams.
	Implicit in this scheme is the notion of in-order delivery of
	priority changes (i.e., dependency tree mutations): since operations
	on the dependency tree such as reparenting a subtree are not
	commutative, both sender and receiver must apply them in the same
	order to ensure that both sides have a consistent view of the stream
	dependency tree. HTTP/2 specifies priority assignments in PRIORITY
	frames and (optionally) in HEADERS frames. To achieve in-order
	delivery of priority changes in HTTP/QUIC, PRIORITY frames are sent
	on the connection control stream and the PRIORITY section is removed
	from the HEADERS frame. The semantics of the Stream Dependency,
	Weight, E flag, and (for HEADERS frames) PRIORITY flag are the same
	as in HTTP/2.
	For consistency's sake, all PRIORITY frames MUST refer to the message		For consistency's sake, all PRIORITY frames MUST refer to the message
	control stream of the dependent request, not the data stream.		control stream of the dependent request, not the data stream.
	4.4. Flow Control		4.4. Server Push
	QUIC provides stream and connection level flow control, similar in
	principle to HTTP/2's flow control but with some implementation
	differences. As flow control is handled by QUIC, the HTTP mapping
	need not concern itself with maintaining flow control state. The
	HTTP mapping MUST NOT send WINDOW_UPDATE frames at the HTTP level.
	4.5. Server Push
	HTTP/QUIC supports server push as described in [RFC7540]. During		HTTP/QUIC supports server push as described in [RFC7540]. During
	connection establishment, the client indicates whether it is willing		connection establishment, the client indicates whether it is willing
	to receive server pushes via the SETTINGS_ENABLE_PUSH setting in the		to receive server pushes via the SETTINGS_DISABLE_PUSH setting in the
	SETTINGS frame (see Section 3), which defaults to 1 (true).		SETTINGS frame (see Section 3), which defaults to 1 (true).
	As with server push for HTTP/2, the server initiates a server push by		As with server push for HTTP/2, the server initiates a server push by
	sending a PUSH_PROMISE frame containing the StreamID of the stream to		sending a PUSH_PROMISE frame containing the StreamID of the stream to
	be pushed, as well as request header fields attributed to the		be pushed, as well as request header fields attributed to the
	request. The PUSH_PROMISE frame is sent on the control stream of the		request. The PUSH_PROMISE frame is sent on the control stream of the
	associated (client-initiated) request, while the Promised Stream ID		associated (client-initiated) request, while the Promised Stream ID
	field specifies the Stream ID of the control stream for the server-		field specifies the Stream ID of the control stream for the server-
	initiated request.		initiated request.
	The server push response is conveyed in the same way as a non-server-		The server push response is conveyed in the same way as a non-server-
	push response, with response headers and (if present) trailers		push response, with response headers and (if present) trailers
	carried by HEADERS frames sent on the control stream, and response		carried by HEADERS frames sent on the control stream, and response
	body (if any) sent via the corresponding data stream.		body (if any) sent via the corresponding data stream.
	5. HTTP Framing Layer		5. HTTP Framing Layer
	Many framing concepts from HTTP/2 can be elided away on QUIC, because
	the transport deals with them. Because frames are already on a
	stream, they can omit the stream number. Because frames do not block
	multiplexing (QUIC's multiplexing occurs below this layer), the
	support for variable-maximum-length packets can be removed. Because
	stream termination is handled by QUIC, an END_STREAM flag is not
	required.
	Frames are used only on the connection (stream 3) and message		Frames are used only on the connection (stream 3) and message
	(streams 5, 9, etc.) control streams. Other streams carry data		(streams 5, 9, etc.) control streams. Other streams carry data
	payload and are not framed at the HTTP layer.		payload and are not framed at the HTTP layer.
	Frame payloads are largely drawn from [RFC7540]. However, QUIC		This section describes HTTP framing in QUIC and highlights some
	includes some features (e.g. flow control) which are also present in		differences from HTTP/2 framing. For more detail on differences from
	HTTP/2. In these cases, the HTTP mapping need not re-implement them.		HTTP/2, see Section 7.1.
	As a result, some frame types are not required when using QUIC.
	Where an HTTP/2-defined frame is no longer used, the frame ID is
	reserved in order to maximize portability between HTTP/2 and HTTP/
	QUIC implementations. However, equivalent frames between the two
	mappings are not necessarily identical.
	This section describes HTTP framing in QUIC and highlights
	differences from HTTP/2 framing.
	5.1. Frame Layout		5.1. 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 (16) | Type (8) | Flags (8) |		| Length (16) | Type (8) | Flags (8) |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Frame Payload (*) ...		| Frame Payload (*) ...
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	HTTP/QUIC frame format		Figure 1: HTTP/QUIC frame format
	5.2. Frame Definitions		5.2. Frame Definitions
	5.2.1. DATA		5.2.1. HEADERS
	DATA frames do not exist. Frame type 0x0 is reserved.
	5.2.2. HEADERS
	The HEADERS frame (type=0x1) is used to carry part of a header set,		The HEADERS frame (type=0x1) is used to carry part of a header set,
	compressed using HPACK [RFC7541]. Because HEADERS frames from		compressed using HPACK [RFC7541].
	different streams will be delivered out-of-order and priority-changes
	are not commutative, the PRIORITY region of HEADERS is not supported.
	A separate PRIORITY frame MUST be used.
	Padding MUST NOT be used. The flags defined are:
	Reserved (0x1): Reserved for HTTP/2 compatibility.		One flag is defined:
	End Header Block (0x4): This frame concludes a header block.		End Header Block (0x4): This frame concludes a header block.
	Reserved (0x8): Reserved for HTTP/2 compatibility.		A HEADERS frame with any other flags set MUST be treated as a
	Reserved (0x20): Reserved for HTTP/2 compatibility.
	A HEADERS frame with the Reserved bits set MUST be treated as a
	connection error of type HTTP_MALFORMED_HEADERS.		connection error of type HTTP_MALFORMED_HEADERS.
	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
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Sequence? (16) | Header Block Fragment (*)...		| Sequence? (16) | Header Block Fragment (*)...
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	HEADERS frame payload		Figure 2: HEADERS frame payload
	The HEADERS frame payload has the following fields:		The HEADERS frame payload has the following fields:
	Sequence Number: Present only on the first frame of a header block		Sequence Number: Present only on the first frame of a header block
	sequence. This MUST be set to zero on the first header block		sequence. This MUST be set to zero on the first header block
	sequence, and incremented on each header block.		sequence, and incremented on each header block.
	The next frame on the same stream after a HEADERS frame without the		The next frame on the same stream after a HEADERS frame without the
	EHB flag set MUST be another HEADERS frame. A receiver MUST treat		EHB flag set MUST be another HEADERS frame. A receiver MUST treat
	the receipt of any other type of frame as a stream error of type		the receipt of any other type of frame as a stream error of type
	skipping to change at page 12, line 25 ¶		skipping to change at page 11, line 35 ¶
	A full header block is contained in a sequence of zero or more		A full header block is contained in a sequence of zero or more
	HEADERS frames without EHB set, followed by a HEADERS frame with EHB		HEADERS frames without EHB set, followed by a HEADERS frame with EHB
	set.		set.
	On receipt, header blocks (HEADERS, PUSH_PROMISE) MUST be processed		On receipt, header blocks (HEADERS, PUSH_PROMISE) MUST be processed
	by the HPACK decoder in sequence. If a block is missing, all		by the HPACK decoder in sequence. If a block is missing, all
	subsequent HPACK frames MUST be held until it arrives, or the		subsequent HPACK frames MUST be held until it arrives, or the
	connection terminated.		connection terminated.
	5.2.3. PRIORITY		When the Sequence counter reaches its maximum value (0xFFFF), the
			next increment returns it to zero. An endpoint MUST NOT wrap the
			Sequence counter to zero until the previous zero-value header block
			has been confirmed received.
			5.2.2. PRIORITY
	The PRIORITY (type=0x02) frame specifies the sender-advised priority		The PRIORITY (type=0x02) frame specifies the sender-advised priority
	of a stream and is substantially different from [RFC7540]. In order		of a stream and is substantially different from [RFC7540]. In order
	to support ordering, it MUST be sent only on the connection control		to support ordering, it MUST be sent only on the connection control
	stream. The format has been modified to accommodate not being sent		stream. The format has been modified to accommodate not being sent
	on-stream and the larger stream ID space of QUIC.		on-stream and the larger stream ID space of QUIC.
			The semantics of the Stream Dependency, Weight, and E flag are the
			same as in HTTP/2.
	The flags defined are:		The flags defined are:
	E (0x01): Indicates that the stream dependency is exclusive (see		E (0x01): Indicates that the stream dependency is exclusive (see
	[RFC7540] Section 5.3).		[RFC7540] Section 5.3).
	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
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Prioritized Stream (32) |		| Prioritized Stream (32) |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Dependent Stream (32) |		| Dependent Stream (32) |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Weight (8) |		| Weight (8) |
	+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+
	HEADERS frame payload		Figure 3: PRIORITY frame payload
	The HEADERS frame payload has the following fields:		The HEADERS frame payload has the following fields:
	Prioritized Stream: A 32-bit stream identifier for the message		Prioritized Stream: A 32-bit stream identifier for the message
	control stream whose priority is being updated.		control stream whose priority is being updated.
	Stream Dependency: A 32-bit stream identifier for the stream that		Stream Dependency: A 32-bit stream identifier for the stream that
	this stream depends on (see Section 4.3 and {!RFC7540}}		this stream depends on (see Section 4.3 and {!RFC7540}}
	Section 5.3).		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 stream (see [RFC7540] Section 5.3). Add one to the value to
	obtain a weight between 1 and 256.		obtain a weight between 1 and 256.
	A PRIORITY frame MUST have a payload length of nine octets. A		A PRIORITY frame MUST have a payload length of nine octets. A
	PRIORITY frame of any other length MUST be treated as a connection		PRIORITY frame of any other length MUST be treated as a connection
	error of type HTTP_MALFORMED_PRIORITY.		error of type HTTP_MALFORMED_PRIORITY.
	5.2.4. RST_STREAM		5.2.3. SETTINGS
	RST_STREAM frames do not exist, since QUIC provides stream lifecycle
	management. Frame type 0x3 is reserved.
	5.2.5. SETTINGS
	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, and is substantially different from [RFC7540].		on peer behavior, and is substantially different from [RFC7540].
	Individually, a SETTINGS parameter can also be referred to as a		Individually, a SETTINGS parameter can also be referred to as a
	"setting".		"setting".
	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 - a peer
	skipping to change at page 13, line 41 ¶		skipping to change at page 13, line 4 ¶
	"setting".		"setting".
	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 - a peer
	uses SETTINGS to advertise a set of supported values. The recipient		uses SETTINGS to advertise a set of supported values. The recipient
	can then choose which entries from this list are also acceptable and		can then choose which entries from this list are also acceptable and
	proceed with the value it has chosen. (This choice could be		proceed with the value it has chosen. (This choice could be
	announced in a field of an extension frame, or in its own value in		announced in a field of an extension frame, or in its own value in
	SETTINGS.)		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 permit a very large HPACK state		peer. For example, a client might permit a very large HPACK state
	table while a server chooses to use a small one to conserve memory.		table while a server chooses to use a small one to conserve memory.
	A SETTINGS frame MAY be sent at any time by either endpoint over the		Parameters MUST NOT occur more than once. A receiver MAY treat the
	lifetime of the connection.		presence of the same parameter more than once as a connection error
			of type HTTP_MALFORMED_SETTINGS.
	Each parameter in a SETTINGS frame replaces any existing value for
	that parameter. Parameters are processed in the order in which they
	appear, and a receiver of a SETTINGS frame does not need to maintain
	any state other than the current value of its parameters. Therefore,
	the value of a SETTINGS parameter is the last value that is seen by a
	receiver.
	The SETTINGS frame defines the following flag:
	REQUEST_ACK (0x1): When set, bit 0 indicates that this frame		The SETTINGS frame defines no flags.
	contains values which the sender wants to know were understood and
	applied. For more information, see Section 5.2.5.3.
	The payload of a SETTINGS frame consists of zero or more parameters,		The payload of a SETTINGS frame consists of zero or more parameters,
	each consisting of an unsigned 16-bit setting identifier and a		each consisting of an unsigned 16-bit setting identifier and a
	length-prefixed binary value.		length-prefixed binary value.
	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
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Identifier (16) |B| Length (15) |		| Identifier (16) | Length (16) |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Contents (?) ...		| Contents (?) ...
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 1: SETTINGS value format		Figure 4: SETTINGS value format
	A zero-length content indicates that the setting value is a Boolean		A zero-length content indicates that the setting value is a Boolean
	given by the B bit. If Length is not zero, the B bit MUST be zero,		and true. False is indicated by the absence of the setting.
	and MUST be ignored by receivers. The initial value of each setting
	is "false" unless otherwise specified by the definition of the
	setting.
	Non-zero-length values MUST be compared against the remaining length		Non-zero-length values MUST be compared against the remaining length
	of the SETTINGS frame. Any value which purports to cross the end of		of the SETTINGS frame. Any value which purports to cross the end of
	the frame MUST cause the SETTINGS frame to be considered malformed		the frame MUST cause the SETTINGS frame to be considered malformed
	and trigger a connection error.		and trigger a connection error of type HTTP_MALFORMED_SETTINGS.
	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.
	and MUST only be sent on the connection control stream (Stream 3).		A SETTINGS frame MUST be sent as the first frame of the connection
	If an endpoint receives an SETTINGS frame whose stream identifier		control stream (see Section 4) by each peer, and MUST NOT be sent
	field is anything other than 0x0, the endpoint MUST respond with a		subsequently or on any other stream. If an endpoint receives an
	connection error of type HTTP_SETTINGS_ON_WRONG_STREAM.		SETTINGS frame on a different stream, the endpoint MUST respond with
			a connection error of type HTTP_SETTINGS_ON_WRONG_STREAM. If an
			endpoint receives a second SETTINGS frame, the endpoint MUST respond
			with a connection error of type HTTP_MULTIPLE_SETTINGS.
	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 5.4.1) of type HTTP_MALFORMED_SETTINGS.		(Section 5.4.1) of type HTTP_MALFORMED_SETTINGS.
	5.2.5.1. Integer encoding		5.2.3.1. Integer encoding
	Settings which are integers are transmitted in network byte order.		Settings which are integers are transmitted in network byte order.
	Leading zero octets are permitted, but implementations SHOULD use		Leading zero octets are permitted, but implementations SHOULD use
	only as many bytes as are needed to represent the value. An integer		only as many bytes as are needed to represent the value. An integer
	MUST NOT be represented in more bytes than would be used to transfer		MUST NOT be represented in more bytes than would be used to transfer
	the maximum permitted value.		the maximum permitted value.
	5.2.5.2. Defined SETTINGS Parameters		5.2.3.2. Defined SETTINGS Parameters
	Some transport-level options that HTTP/2 specifies via the SETTINGS
	frame are superseded by QUIC transport parameters in HTTP/QUIC.
	Below is a listing of how each HTTP/2 SETTINGS parameter is mapped:
	SETTINGS_HEADER_TABLE_SIZE: An integer with a maximum value of 2^32
	- 1.
	SETTINGS_ENABLE_PUSH: Transmitted as a Boolean. The default remains
	"true" as specified in [RFC7540].
	SETTINGS_MAX_CONCURRENT_STREAMS: QUIC requires the maximum number of
	incoming streams per connection to be specified in the initial
	crypto handshake, using the "MSPC" tag. Specifying
	SETTINGS_MAX_CONCURRENT_STREAMS in the SETTINGS frame is an error.
	SETTINGS_INITIAL_WINDOW_SIZE: QUIC requires both stream and
	connection flow control window sizes to be specified in the
	initial crypto handshake, using the "SFCW" and "CFCW" tags,
	respectively. Specifying SETTINGS_INITIAL_WINDOW_SIZE in the
	SETTINGS frame is an error.
	SETTINGS_MAX_FRAME_SIZE: This setting has no equivalent in QUIC.		The following settings are defined in HTTP/QUIC:
	Specifying it in the SETTINGS frame is an error.
	SETTINGS_MAX_HEADER_LIST_SIZE: An integer with a maximium value of		SETTINGS_HEADER_TABLE_SIZE (0x1): An integer with a maximum value of
	2^32 - 1.		2^32 - 1.
	5.2.5.3. Settings Synchronization		SETTINGS_DISABLE_PUSH (0x2): Transmitted as a Boolean; replaces
			SETTINGS_ENABLE_PUSH
	Some values in SETTINGS benefit from or require an understanding of
	when the peer has received and applied the changed parameter values.
	In order to provide such synchronization timepoints, the recipient of
	a SETTINGS frame MUST apply the updated parameters as soon as
	possible upon receipt. The values in the SETTINGS frame MUST be
	processed in the order they appear, with no other frame processing
	between values. Unsupported parameters MUST be ignored.
	Once all values have been processed, if the REQUEST_ACK flag was set,		SETTINGS_MAX_HEADER_LIST_SIZE (0x6): An integer with a maximum value
	the recipient MUST emit the following frames:		of 2^32 - 1.
	o On the connection control stream, a SETTINGS_ACK frame		5.2.3.3. Usage in 0-RTT
	(Section 5.2.11) listing the identifiers whose values were not
	understood.
	o On each request control stream which is not in the "half-closed		When a 0-RTT QUIC connection is being used, the client's initial
	(local)" or "closed" state, an empty SETTINGS_ACK frame.		requests will be sent before the arrival of the server's SETTINGS
			frame. Clients SHOULD cache at least the following settings about
			servers:
	The SETTINGS_ACK frame on the connection control stream contains the		o SETTINGS_HEADER_TABLE_SIZE
	highest stream number which was open at the time the SETTINGS frame
	was received. All streams with higher numbers can safely be assumed
	to have the new settings in effect when they open.
	For already-open streams including the connection control stream, the		o SETTINGS_MAX_HEADER_LIST_SIZE
	SETTINGS_ACK frame indicates the point at which the new settings took
	effect, if they did so before the peer half-closed the stream. If
	the peer closed the stream before receiving the SETTINGS frame, the
	previous settings were in effect for the full lifetime of that
	stream.
	In certain conditions, the SETTINGS_ACK frame can be the first frame		Clients MUST comply with cached settings until the server's current
	on a given stream - this simply indicates that the new settings apply		settings are received. If a client does not have cached values, it
	from the beginning of that stream.		SHOULD assume the following values:
	If the sender of a SETTINGS frame with the REQUEST_ACK flag set does		o SETTINGS_HEADER_TABLE_SIZE: 0 octets
	not receive full acknowledgement within a reasonable amount of time,
	it MAY issue a connection error (Section 6) of type
	HTTP_SETTINGS_TIMEOUT. A full acknowledgement has occurred when:
	o All previous SETTINGS frames have been fully acknowledged,		o SETTINGS_MAX_HEADER_LIST_SIZE: 16,384 octets
	o A SETTINGS_ACK frame has been received on the connection control		Servers MAY continue processing data from clients which exceed its
	stream,		current configuration during the initial flight. In this case, the
			client MUST apply the new settings immediately upon receipt.
	o All message control streams with a Stream ID through those given		If the connection is closed because these or other constraints were
	in the SETTINGS_ACK frame have either closed or received a		violated during the 0-RTT flight (e.g. with
	SETTINGS_ACK frame.		HTTP_HPACK_DECOMPRESSION_FAILED), clients MAY establish a new
			connection and retry any 0-RTT requests using the settings sent by
			the server on the closed connection. (This assumes that only
			requests that are safe to retry are sent in 0-RTT.) If the
			connection was closed before the SETTINGS frame was received, clients
			SHOULD discard any cached values and use the defaults above on the
			next connection.
	5.2.6. PUSH_PROMISE		5.2.4. PUSH_PROMISE
	The PUSH_PROMISE frame (type=0x05) is used to carry a request header		The PUSH_PROMISE frame (type=0x05) is used to carry a request header
	set from server to client, as in HTTP/2. It defines no flags.		set from server to client, as in HTTP/2. It defines no flags.
	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
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Promised Stream ID (32) |		| Promised Stream ID (32) |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Sequence? (16) | Header Block (*) ...		| Sequence? (16) | Header Block (*) ...
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	PUSH_PROMISE frame payload		Figure 5: PUSH_PROMISE frame payload
	The payload consists of:		The payload consists of:
	Promised Stream ID: A 32-bit Stream ID indicating the QUIC stream on		Promised Stream ID: A 32-bit Stream ID indicating the QUIC stream on
	which the response headers will be sent. (The response body		which the response headers will be sent. (The response body
	stream is implied by the headers stream, as defined in Section 4.)		stream is implied by the headers stream, as defined in Section 4.)
	HPACK Sequence: A sixteen-bit counter, equivalent to the Sequence		HPACK Sequence: A sixteen-bit counter, equivalent to the Sequence
	field in HEADERS		field in HEADERS
	Payload: HPACK-compressed request headers for the promised response.		Payload: HPACK-compressed request headers for the promised response.
	TODOs:		6. Error Handling
	o QUIC stream space may be enlarged; would need to redefine Promised
	Stream field in this case.
	o No CONTINUATION - HEADERS have EHB; do we need it here?
	5.2.7. PING
	PING frames do not exist, since QUIC provides equivalent
	functionality. Frame type 0x6 is reserved.
	5.2.8. GOAWAY frame
	GOAWAY frames do not exist, since QUIC provides equivalent
	functionality. Frame type 0x7 is reserved.
	5.2.9. WINDOW_UPDATE frame
	WINDOW_UPDATE frames do not exist, since QUIC provides equivalent
	functionality. Frame type 0x8 is reserved.
	5.2.10. CONTINUATION frame
	CONTINUATION frames do not exist, since larger supported HEADERS/
	PUSH_PROMISE frames provide equivalent functionality. Frame type 0x9
	is reserved.
	5.2.11. SETTINGS_ACK Frame
	The SETTINGS_ACK frame (id = 0x0b) acknowledges receipt and
	application of specific values in the peer's SETTINGS frame.
	Depending on the stream where it is sent, it takes two different
	forms.
	On the connection control stream, it contains information about how
	and when the sender has processed the most recently-received SETTINGS
	frame, and has the following payload:
	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
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Highest Local Stream (32) |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Highest Remote Stream (32) |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Unrecognized Identifiers (*) ...
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 2: SETTINGS_ACK connection control stream format
	Highest Local Stream (32 bits): The highest locally-initiated Stream
	ID which is not in the "idle" state
	Highest Remote Stream (32 bits): The highest peer-initiated Stream
	ID which is not in the "idle" state
	Unrecognized Identifiers: A list of 16-bit SETTINGS identifiers
	which the sender has not understood and therefore ignored. This
	list MAY be empty.
	On message control streams, the SETTINGS_ACK frame carries no
	payload, and is strictly a synchronization marker for settings
	application. See Section 5.2.5.3 for more detail. A SETTINGS_ACK
	frame with a non-zero length MUST be treated as a connection error of
	type HTTP_MALFORMED_SETTINGS_ACK.
	On the connection control stream, the SETTINGS_ACK frame MUST have a		QUIC allows the application to abruptly terminate individual streams
	length which is a multiple of two octets. A SETTINGS_ACK frame of		or the entire connection when an error is encountered. These are
	any other length MUST be treated as a connection error of type		referred to as "stream errors" or "connection errors" and are
	HTTP_MALFORMED_SETTINGS_ACK.		described in more detail in [QUIC-TRANSPORT].
	6. Error Handling		HTTP/QUIC requires that only data streams be terminated abruptly.
			Terminating a message control stream will result in an error of type
			HTTP_RST_CONTROL_STREAM.
	This section describes the specific error codes defined by HTTP and		This section describes HTTP-specific error codes which can be used to
	the mapping of HTTP/2 error codes into the QUIC error code space.		express the cause of a connection or stream error.
	6.1. HTTP-Defined QUIC Error Codes		6.1. HTTP-Defined QUIC Error Codes
	QUIC allocates error codes 0x0000-0x3FFF to application protocol		QUIC allocates error codes 0x0000-0x3FFF to application protocol
	definition. The following error codes are defined by HTTP for use in		definition. The following error codes are defined by HTTP for use in
	QUIC RST_STREAM, GOAWAY, and CONNECTION_CLOSE frames.		QUIC RST_STREAM, GOAWAY, and CONNECTION_CLOSE frames.
	HTTP_SETTINGS_TIMEOUT (0x00): After sending a SETTINGS frame which
	requested acknowledgement, the acknowledgement was not completed
	(see Section 5.2.5.3) in a timely manner.
	HTTP_PUSH_REFUSED (0x01): The server has attempted to push content		HTTP_PUSH_REFUSED (0x01): 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 (0x02): An internal error has occurred in the		HTTP_INTERNAL_ERROR (0x02): An internal error has occurred in the
	HTTP stack.		HTTP stack.
	HTTP_PUSH_ALREADY_IN_CACHE (0x03): The server has attempted to push		HTTP_PUSH_ALREADY_IN_CACHE (0x03): The server has attempted to push
	content which the client has cached.		content which the client has cached.
	HTTP_REQUEST_CANCELLED (0x04): The client no longer needs the		HTTP_REQUEST_CANCELLED (0x04): The client no longer needs the
	skipping to change at page 19, line 47 ¶		skipping to change at page 16, line 38 ¶
	HTTP_EXCESSIVE_LOAD (0x07): The endpoint detected that its peer is		HTTP_EXCESSIVE_LOAD (0x07): 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 (0x08): The requested operation cannot be		HTTP_VERSION_FALLBACK (0x08): The requested operation cannot be
	served over HTTP/QUIC. The peer should retry over HTTP/2.		served over HTTP/QUIC. The peer should retry over HTTP/2.
	HTTP_MALFORMED_HEADERS (0x09): A HEADERS frame has been received		HTTP_MALFORMED_HEADERS (0x09): A HEADERS frame has been received
	with an invalid format.		with an invalid format.
	HTTP_MALFORMED_PRIORITY (0x0A): A HEADERS frame has been received		HTTP_MALFORMED_PRIORITY (0x0A): A PRIORITY frame has been received
	with an invalid format.		with an invalid format.
	HTTP_MALFORMED_SETTINGS (0x0B): A HEADERS frame has been received		HTTP_MALFORMED_SETTINGS (0x0B): A SETTINGS frame has been received
	with an invalid format.		with an invalid format.
	HTTP_MALFORMED_PUSH_PROMISE (0x0C): A HEADERS frame has been		HTTP_MALFORMED_PUSH_PROMISE (0x0C): A PUSH_PROMISE frame has been
	received with an invalid format.
	HTTP_MALFORMED_SETTINGS_ACK (0x0D): A HEADERS frame has been
	received with an invalid format.		received with an invalid format.
	HTTP_INTERRUPTED_HEADERS (0x0E): A HEADERS frame without the End		HTTP_INTERRUPTED_HEADERS (0x0E): A HEADERS frame without the End
	Header Block flag was followed by a frame other than HEADERS.		Header Block flag was followed by a frame other than HEADERS.
	HTTP_SETTINGS_ON_WRONG_STREAM (0x0F): A SETTINGS frame was received		HTTP_SETTINGS_ON_WRONG_STREAM (0x0F): A SETTINGS frame was received
	on a request control stream.		on a request control stream.
	6.2. Mapping HTTP/2 Error Codes		HTTP_MULTIPLE_SETTINGS (0x10): More than one SETTINGS frame was
			received.
			HTTP_RST_CONTROL_STREAM (0x11): A message control stream closed
			abruptly.
			7. Considerations for Transitioning from HTTP/2
			HTTP/QUIC is strongly informed by HTTP/2, and bears many
			similarities. This section points out important differences from
			HTTP/2 and describes how to map HTTP/2 extensions into HTTP/QUIC.
			7.1. HTTP Frame Types
			Many framing concepts from HTTP/2 can be elided away on QUIC, because
			the transport deals with them. Because frames are already on a
			stream, they can omit the stream number. Because frames do not block
			multiplexing (QUIC's multiplexing occurs below this layer), the
			support for variable-maximum-length packets can be removed. Because
			stream termination is handled by QUIC, an END_STREAM flag is not
			required.
			Frame payloads are largely drawn from [RFC7540]. However, QUIC
			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.
			As a result, several HTTP/2 frame types are not required in HTTP/
			QUIC. Where an HTTP/2-defined frame is no longer used, the frame ID
			has been reserved in order to maximize portability between HTTP/2 and
			HTTP/QUIC implementations. However, even equivalent frames between
			the two mappings are not identical.
			Many of the differences arise from the fact that HTTP/2 provides an
			absolute ordering between frames across all streams, while QUIC
			provides this guarantee on each stream only. As a result, if a frame
			type makes assumptions that frames from different streams will still
			be received in the order sent, HTTP/QUIC will break them.
			For example, implicit in the HTTP/2 prioritization scheme is the
			notion of in-order delivery of priority changes (i.e., dependency
			tree mutations): since operations on the dependency tree such as
			reparenting a subtree are not commutative, both sender and receiver
			must apply them in the same order to ensure that both sides have a
			consistent view of the stream dependency tree. HTTP/2 specifies
			priority assignments in PRIORITY frames and (optionally) in HEADERS
			frames. To achieve in-order delivery of priority changes in HTTP/
			QUIC, PRIORITY frames are sent on the connection control stream and
			the PRIORITY section is removed from the HEADERS frame.
			Other than this issue, frame type HTTP/2 extensions are typically
			portable to QUIC simply by replacing Stream 0 in HTTP/2 with Stream 3
			in HTTP/QUIC.
			Below is a listing of how each HTTP/2 frame type is mapped:
			DATA (0x0): Instead of DATA frames, HTTP/QUIC uses a separate data
			stream. See Section 4.
			HEADERS (0x1): As described above, the PRIORITY region of HEADERS is
			not supported. A separate PRIORITY frame MUST be used. Padding
			is not defined in HTTP/QUIC frames. See Section 5.2.1.
			PRIORITY (0x2): As described above, the PRIORITY frame is sent on
			the connection control stream. See Section 5.2.2.
			RST_STREAM (0x3): RST_STREAM frames do not exist, since QUIC
			provides stream lifecycle management.
			SETTINGS (0x4): SETTINGS frames are sent only at the beginning of
			the connection. See Section 5.2.3 and Section 7.2.
			PUSH_PROMISE (0x5): See Section 5.2.4.
			PING (0x6): PING frames do not exist, since QUIC provides equivalent
			functionality.
			GOAWAY (0x7): GOAWAY frames do not exist, since QUIC provides
			equivalent functionality.
			WINDOW_UPDATE (0x8): WINDOW_UPDATE frames do not exist, since QUIC
			provides flow control.
			CONTINUATION (0x9): CONTINUATION frames do not exist; instead,
			larger HEADERS/PUSH_PROMISE frames than HTTP/2 are permitted, and
			HEADERS frames can be used in series.
			The IANA registry of frame types has been updated in Section 9.3 to
			include references to the definition for each frame type in HTTP/2
			and in HTTP/QUIC. Frames not defined as available in HTTP/QUIC
			SHOULD NOT be sent and SHOULD be ignored as unknown on receipt.
			7.2. HTTP/2 SETTINGS Parameters
			An important difference from HTTP/2 is that settings are sent once,
			at the beginning of the connection, and thereafter cannot change.
			This eliminates many corner cases around synchronization of changes.
			Some transport-level options that HTTP/2 specifies via the SETTINGS
			frame are superseded by QUIC transport parameters in HTTP/QUIC. The
			HTTP-level options that are retained in HTTP/QUIC have the same value
			as in HTTP/2.
			Below is a listing of how each HTTP/2 SETTINGS parameter is mapped:
			SETTINGS_HEADER_TABLE_SIZE: See Section 5.2.3.2.
			SETTINGS_ENABLE_PUSH: See SETTINGS_DISABLE_PUSH in Section 5.2.3.2.
			SETTINGS_MAX_CONCURRENT_STREAMS: QUIC requires the maximum number of
			incoming streams per connection to be specified in the initial
			transport handshake. Specifying SETTINGS_MAX_CONCURRENT_STREAMS
			in the SETTINGS frame is an error.
			SETTINGS_INITIAL_WINDOW_SIZE: QUIC requires both stream and
			connection flow control window sizes to be specified in the
			initial transport handshake. Specifying
			SETTINGS_INITIAL_WINDOW_SIZE in the SETTINGS frame is an error.
			SETTINGS_MAX_FRAME_SIZE: This setting has no equivalent in HTTP/
			QUIC. Specifying it in the SETTINGS frame is an error.
			SETTINGS_MAX_HEADER_LIST_SIZE: See Section 5.2.3.2.
			Settings defined by extensions to HTTP/2 MAY be expressed as integers
			with a maximum value of 2^32-1, if they are applicable to HTTP/QUIC,
			but SHOULD have a specification describing their usage. Fields for
			this purpose have been added to the IANA registry in Section 9.4.
			7.3. HTTP/2 Error Codes
			QUIC has the same concepts of "stream" and "connection" errors that
			HTTP/2 provides. However, because the error code space is shared
			between multiple components, there is no direct portability of HTTP/2
			error codes.
	The HTTP/2 error codes defined in Section 7 of [RFC7540] map to QUIC		The HTTP/2 error codes defined in Section 7 of [RFC7540] map to QUIC
	error codes as follows:		error codes as follows:
	NO_ERROR (0x0): QUIC_NO_ERROR		NO_ERROR (0x0): QUIC_NO_ERROR
	PROTOCOL_ERROR (0x1): No single mapping. See new HTTP_MALFORMED_*		PROTOCOL_ERROR (0x1): No single mapping. See new HTTP_MALFORMED_*
	error codes defined in Section 6.1.		error codes defined in Section 6.1.
	INTERNAL_ERROR (0x2) HTTP_INTERNAL_ERROR in Section 6.1.		INTERNAL_ERROR (0x2) HTTP_INTERNAL_ERROR in Section 6.1.
	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
	from the QUIC layer.		from the QUIC layer.
	SETTINGS_TIMEOUT (0x4): HTTP_SETTINGS_TIMEOUT in Section 6.1.		SETTINGS_TIMEOUT (0x4): Not applicable, since no acknowledgement of
			SETTINGS is defined.
	STREAM_CLOSED (0x5): Not applicable, since QUIC handles stream		STREAM_CLOSED (0x5): Not applicable, since QUIC handles stream
	management. Would provoke a QUIC_STREAM_DATA_AFTER_TERMINATION		management. Would provoke a QUIC_STREAM_DATA_AFTER_TERMINATION
	from the QUIC layer.		from the QUIC layer.
	FRAME_SIZE_ERROR (0x6) No single mapping. See new error codes		FRAME_SIZE_ERROR (0x6) No single mapping. See new error codes
	defined in Section 6.1.		defined in Section 6.1.
	REFUSED_STREAM (0x7): Not applicable, since QUIC handles stream		REFUSED_STREAM (0x7): Not applicable, since QUIC handles stream
	management. Would provoke a QUIC_TOO_MANY_OPEN_STREAMS from the		management. Would provoke a QUIC_TOO_MANY_OPEN_STREAMS from the
	skipping to change at page 21, line 12 ¶		skipping to change at page 20, line 37 ¶
	CONNECT_ERROR (0xa): HTTP_CONNECT_ERROR in Section 6.1.		CONNECT_ERROR (0xa): HTTP_CONNECT_ERROR in Section 6.1.
	ENHANCE_YOUR_CALM (0xb): HTTP_EXCESSIVE_LOAD in Section 6.1.		ENHANCE_YOUR_CALM (0xb): HTTP_EXCESSIVE_LOAD in Section 6.1.
	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 6.1.		HTTP_1_1_REQUIRED (0xd): HTTP_VERSION_FALLBACK in Section 6.1.
	TODO: fill in missing error code mappings.		Error codes defined by HTTP/2 extensions need to be re-registered for
			HTTP/QUIC if still applicable. See Section 9.5.
	7. Security Considerations		8. Security Considerations
	The security considerations of HTTP over QUIC should be comparable to		The security considerations of HTTP over QUIC should be comparable to
	those of HTTP/2.		those of HTTP/2.
	The modified SETTINGS format contains nested length elements, which		The modified SETTINGS format contains nested length elements, which
	could pose a security risk to an uncautious implementer. A SETTINGS		could pose a security risk to an uncautious implementer. A SETTINGS
	frame parser MUST ensure that the length of the frame exactly matches		frame parser MUST ensure that the length of the frame exactly matches
	the length of the settings it contains.		the length of the settings it contains.
	8. IANA Considerations		9. IANA Considerations
	8.1. Registration of HTTP/QUIC Identification String		9.1. Registration of HTTP/QUIC 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/QUIC in the "Application Layer Protocol Negotiation (ALPN)
	Protocol IDs" registry established in [RFC7301].		Protocol IDs" registry established in [RFC7301].
	The "hq" string identifies HTTP/QUIC:		The "hq" string identifies HTTP/QUIC:
	Protocol: HTTP over QUIC		Protocol: HTTP over QUIC
	Identification Sequence: 0x68 0x71 ("hq")		Identification Sequence: 0x68 0x71 ("hq")
	Specification: This document		Specification: This document
	8.2. Registration of Version Hint Alt-Svc Parameter		9.2. 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: "v"		Parameter: "quic"
	Specification: This document, Section 2.1		Specification: This document, Section 2.1
	8.3. Existing Frame Types		9.3. Existing Frame Types
	This document adds two new columns to the "HTTP/2 Frame Type"		This document adds two new columns to the "HTTP/2 Frame Type"
	registry defined in [RFC7540]:		registry defined in [RFC7540]:
	Supported Protocols: Indicates which associated protocols use the		Supported Protocols: Indicates which associated protocols use the
	frame type. Values MUST be one of:		frame type. Values MUST be one of:
	* "HTTP/2 only"		* "HTTP/2 only"
	* "HTTP/QUIC only"		* "HTTP/QUIC only"
	* "Both"		* "Both"
	HTTP/QUIC Specification: Indicates where this frame's behavior over		HTTP/QUIC Specification: Indicates where this frame's behavior over
	QUIC is defined; required if the frame is supported over QUIC.		QUIC is defined; required if the frame is supported over QUIC.
	Values for existing registrations are assigned by this document:		Values for existing registrations are assigned by this document:
	+---+---------------+---------------------+-------------------------+		+---------------+---------------------+-------------------------+
	| | Frame Type | Supported Protocols | HTTP/QUIC Specification |		| Frame Type | Supported Protocols | HTTP/QUIC Specification |
	+---+---------------+---------------------+-------------------------+		+---------------+---------------------+-------------------------+
	| | DATA | HTTP/2 only | N/A |		| DATA | HTTP/2 only | N/A |
	| | | | |		| | | |
	| | HEADERS | Both | Section 5.2.2 |		| HEADERS | Both | Section 5.2.1 |
	| | | | |		| | | |
	| | PRIORITY | Both | Section 5.2.3 |		| PRIORITY | Both | Section 5.2.2 |
	| | | | |		| | | |
	| | RST_STREAM | HTTP/2 only | N/A |		| RST_STREAM | HTTP/2 only | N/A |
	| | | | |		| | | |
	| | SETTINGS | Both | Section 5.2.5 |		| SETTINGS | Both | Section 5.2.3 |
	| | | | |		| | | |
	| | PUSH_PROMISE | Both | Section 5.2.6 |		| PUSH_PROMISE | Both | Section 5.2.4 |
	| | | | |		| | | |
	| | PING | HTTP/2 only | N/A |		| PING | HTTP/2 only | N/A |
	| | | | |		| | | |
	| | GOAWAY | HTTP/2 only | N/A |		| GOAWAY | HTTP/2 only | N/A |
	| | | | |		| | | |
	| | WINDOW_UPDATE | HTTP/2 only | N/A |		| WINDOW_UPDATE | HTTP/2 only | N/A |
	| | | | |		| | | |
	| | CONTINUATION | HTTP/2 only | N/A |		| CONTINUATION | HTTP/2 only | N/A |
	+---+---------------+---------------------+-------------------------+		+---------------+---------------------+-------------------------+
	The "Specification" column is renamed to "HTTP/2 specification" and		The "Specification" column is renamed to "HTTP/2 specification" and
	is only required if the frame is supported over HTTP/2.		is only required if the frame is supported over HTTP/2.
	8.4. New Frame Types		9.4. Settings Parameters
	This document adds one new entry to the "HTTP/2 Frame Type" registry		This document adds two new columns to the "HTTP/2 Settings" registry
	defined in [RFC7540]:		defined in [RFC7540]:
	Frame Type: SETTINGS_ACK		Supported Protocols: Indicates which associated protocols use the
			setting. Values MUST be one of:
	Code: 0x0b		* "HTTP/2 only"
	HTTP/2 Specification: N/A		* "HTTP/QUIC only"
	Supported Protocols: HTTP/QUIC only		* "Both"
	HTTP/QUIC Specification: Section 5.2.11		HTTP/QUIC Specification: Indicates where this setting's behavior
			over QUIC is defined; required if the frame is supported over
			QUIC.
	9. References		Values for existing registrations are assigned by this document:
	9.1. Normative References		+-------------------------+------------------+----------------------+
			| Setting Name | Supported | HTTP/QUIC |
			| | Protocols | Specification |
			+-------------------------+------------------+----------------------+
			| HEADER_TABLE_SIZE | Both | Section 5.2.3.2 |
			| | | |
			| ENABLE_PUSH / | Both | Section 5.2.3.2 |
			| DISABLE_PUSH | | |
			| | | |
			| MAX_CONCURRENT_STREAMS | HTTP/2 Only | N/A |
			| | | |
			| INITIAL_WINDOW_SIZE | HTTP/2 Only | N/A |
			| | | |
			| MAX_FRAME_SIZE | HTTP/2 Only | N/A |
			| | | |
			| MAX_HEADER_LIST_SIZE | Both | Section 5.2.3.2 |
			+-------------------------+------------------+----------------------+
	[QUIC-TLS]		The "Specification" column is renamed to "HTTP/2 Specification" and
	Thomson, M., Ed. and S. Turner, Ed, Ed., "Using Transport		is only required if the setting is supported over HTTP/2.
	Layer Security (TLS) to Secure QUIC".
			9.5. Error Codes
			This document establishes a registry for HTTP/QUIC error codes. The
			"HTTP/QUIC Error Code" registry manages a 30-bit space. The "HTTP/
			QUIC Error Code" registry operates under the "Expert Review" policy
			[RFC5226].
			Registrations for error codes are required to include a description
			of the error code. An expert reviewer is advised to examine new
			registrations for possible duplication with existing error codes.
			Use of existing registrations is to be encouraged, but not mandated.
			New registrations are advised to provide the following information:
			Name: A name for the error code. Specifying an error code name is
			optional.
			Code: The 30-bit error code value.
			Description: A brief description of the error code semantics, longer
			if no detailed specification is provided.
			Specification: An optional reference for a specification that
			defines the error code.
			The entries in the following table are registered by this document.
			+------------------------------+-----+--------------+---------------+
			| Name | Cod | Description | Specification |
			| | e | | |
			+------------------------------+-----+--------------+---------------+
			| HTTP_PUSH_REFUSED | 0x0 | Client | Section 6.1 |
			| | 1 | refused | |
			| | | pushed | |
			| | | content | |
			| | | | |
			| HTTP_INTERNAL_ERROR | 0x0 | Internal | Section 6.1 |
			| | 2 | error | |
			| | | | |
			| HTTP_PUSH_ALREADY_IN_CACHE | 0x0 | Pushed | Section 6.1 |
			| | 3 | content | |
			| | | already | |
			| | | cached | |
			| | | | |
			| HTTP_REQUEST_CANCELLED | 0x0 | Data no | Section 6.1 |
			| | 4 | longer | |
			| | | needed | |
			| | | | |
			| HTTP_HPACK_DECOMPRESSION_FAI | 0x0 | HPACK cannot | Section 6.1 |
			| LED | 5 | continue | |
			| | | | |
			| HTTP_CONNECT_ERROR | 0x0 | TCP reset or | Section 6.1 |
			| | 6 | error on | |
			| | | CONNECT | |
			| | | request | |
			| | | | |
			| HTTP_EXCESSIVE_LOAD | 0x0 | Peer | Section 6.1 |
			| | 7 | generating | |
			| | | excessive | |
			| | | load | |
			| | | | |
			| HTTP_VERSION_FALLBACK | 0x0 | Retry over | Section 6.1 |
			| | 8 | HTTP/2 | |
			| | | | |
			| HTTP_MALFORMED_HEADERS | 0x0 | Invalid | Section 6.1 |
			| | 9 | HEADERS | |
			| | | frame | |
			| | | | |
			| HTTP_MALFORMED_PRIORITY | 0x0 | Invalid | Section 6.1 |
			| | A | PRIORITY | |
			| | | frame | |
			| | | | |
			| HTTP_MALFORMED_SETTINGS | 0x0 | Invalid | Section 6.1 |
			| | B | SETTINGS | |
			| | | frame | |
			| | | | |
			| HTTP_MALFORMED_PUSH_PROMISE | 0x0 | Invalid | Section 6.1 |
			| | C | PUSH_PROMISE | |
			| | | frame | |
			| | | | |
			| HTTP_INTERRUPTED_HEADERS | 0x0 | Incomplete | Section 6.1 |
			| | E | HEADERS | |
			| | | block | |
			| | | | |
			| HTTP_SETTINGS_ON_WRONG_STREA | 0x0 | SETTINGS | Section 6.1 |
			| M | F | frame on a | |
			| | | request | |
			| | | control | |
			| | | stream | |
			| | | | |
			| HTTP_MULTIPLE_SETTINGS | 0x1 | Multiple | Section 6.1 |
			| | 0 | SETTINGS | |
			| | | frames | |
			| | | | |
			| HTTP_RST_CONTROL_STREAM | 0x1 | Message | Section 6.1 |
			| | 1 | control | |
			| | | stream was | |
			| | | RST | |
			+------------------------------+-----+--------------+---------------+
			10. References
			10.1. Normative References
	[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".		Multiplexed and Secure Transport".
	[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,
	<http://www.rfc-editor.org/info/rfc793>.		<http://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
	skipping to change at page 24, line 18 ¶		skipping to change at page 26, line 23 ¶
	<http://www.rfc-editor.org/info/rfc7540>.		<http://www.rfc-editor.org/info/rfc7540>.
	[RFC7541] Peon, R. and H. Ruellan, "HPACK: Header Compression for		[RFC7541] Peon, R. and H. Ruellan, "HPACK: Header Compression for
	HTTP/2", RFC 7541, DOI 10.17487/RFC7541, May 2015,		HTTP/2", RFC 7541, DOI 10.17487/RFC7541, May 2015,
	<http://www.rfc-editor.org/info/rfc7541>.		<http://www.rfc-editor.org/info/rfc7541>.
	[RFC7838] Nottingham, M., McManus, P., and J. Reschke, "HTTP		[RFC7838] 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, <http://www.rfc-editor.org/info/rfc7838>.		April 2016, <http://www.rfc-editor.org/info/rfc7838>.
	9.2. Informative References		10.2. Informative References
			[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
			IANA Considerations Section in RFCs", BCP 26, RFC 5226,
			DOI 10.17487/RFC5226, May 2008,
			<http://www.rfc-editor.org/info/rfc5226>.
	[RFC7301] Friedl, S., Popov, A., Langley, A., and E. Stephan,		[RFC7301] Friedl, S., Popov, A., Langley, A., and E. Stephan,
	"Transport Layer Security (TLS) Application-Layer Protocol		"Transport Layer Security (TLS) Application-Layer Protocol
	Negotiation Extension", RFC 7301, DOI 10.17487/RFC7301,		Negotiation Extension", RFC 7301, DOI 10.17487/RFC7301,
	July 2014, <http://www.rfc-editor.org/info/rfc7301>.		July 2014, <http://www.rfc-editor.org/info/rfc7301>.
	Appendix A. Contributors		Appendix A. Contributors
	The original authors of this specification were Robbie Shade and Mike		The original authors of this specification were Robbie Shade and Mike
	Warres.		Warres.
	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-00:		B.1. Since draft-ietf-quic-http-01:
	o Changed "HTTP/2-over-QUIC" to "HTTP/QUIC" throughout		o SETTINGS changes (#181):
			* SETTINGS can be sent only once at the start of a connection; no
			changes thereafter
			* SETTINGS_ACK removed
			* Settings can only occur in the SETTINGS frame a single time
			* Boolean format updated
			o Alt-Svc parameter changed from "v" to "quic"; format updated
			(#229)
			o Closing the connection control stream or any message control
			stream is a fatal error (#176)
			o HPACK Sequence counter can wrap (#173)
			o 0-RTT guidance added
			o Guide to differences from HTTP/2 and porting HTTP/2 extensions
			added (#127,#242)
			B.2. Since draft-ietf-quic-http-00:
			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		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.		order (#75)
	o Described CONNECT pseudo-method		o Described CONNECT pseudo-method (#95)
	o Updated ALPN token and Alt-Svc guidance		o Updated ALPN token and Alt-Svc guidance (#13,#87)
	o Application-layer-defined error codes		o Application-layer-defined error codes (#19,#74)
	B.2. Since draft-shade-quic-http2-mapping-00:		B.3. 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.
	Author's Address		Author's Address
	Mike Bishop (editor)		Mike Bishop (editor)
	Microsoft		Microsoft
End of changes. 105 change blocks.
	405 lines changed or deleted		543 lines changed or added
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