draft-ietf-quic-http-34.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 February 2, 2021		Intended status: Standards Track April 9, 2021
	Expires: August 6, 2021		Expires: October 11, 2021
	Hypertext Transfer Protocol Version 3 (HTTP/3)		Hypertext Transfer Protocol Version 3 (HTTP/3)
	draft-ietf-quic-http-34		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 HTTP/3.		how HTTP/2 extensions can be ported to HTTP/3.
	skipping to change at page 2, line 4 ¶		skipping to change at page 2, line 4 ¶
	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 https://datatracker.ietf.org/drafts/current/.		Drafts is at https://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 August 6, 2021.		This Internet-Draft will expire on October 11, 2021.
	Copyright Notice		Copyright Notice
	Copyright (c) 2021 IETF Trust and the persons identified as the		Copyright (c) 2021 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
	skipping to change at page 9, line 29 ¶		skipping to change at page 9, line 29 ¶
	certificate cannot be verified with respect to the URI's origin		certificate cannot be verified with respect to the URI's origin
	server, the client MUST NOT consider the server authoritative for		server, the client MUST NOT consider the server authoritative for
	that origin.		that origin.
	A client MAY attempt access to a resource with an "https" URI by		A client MAY attempt access to a resource with an "https" URI by
	resolving the host identifier to an IP address, establishing a QUIC		resolving the host identifier to an IP address, establishing a QUIC
	connection to that address on the indicated port (including		connection to that address on the indicated port (including
	validation of the server certificate as described above), and sending		validation of the server certificate as described above), and sending
	an HTTP/3 request message targeting the URI to the server over that		an HTTP/3 request message targeting the URI to the server over that
	secured connection. Unless some other mechanism is used to select		secured connection. Unless some other mechanism is used to select
	HTTP/3, the token "h3" is used in the Application Layer Protocol		HTTP/3, the token "h3" is used in the Application-Layer Protocol
	Negotiation (ALPN; see [RFC7301]) extension during the TLS handshake.		Negotiation (ALPN; see [RFC7301]) extension during the TLS handshake.
	Connectivity problems (e.g., blocking UDP) can result in QUIC		Connectivity problems (e.g., blocking UDP) can result in QUIC
	connection establishment failure; clients SHOULD attempt to use TCP-		connection establishment failure; clients SHOULD attempt to use TCP-
	based versions of HTTP in this case.		based versions of HTTP in this case.
	Servers MAY serve HTTP/3 on any UDP port; an alternative service		Servers MAY serve HTTP/3 on any UDP port; an alternative service
	advertisement always includes an explicit port, and URIs contain		advertisement always includes an explicit port, and URIs contain
	either an explicit port or a default port associated with the scheme.		either an explicit port or a default port associated with the scheme.
	skipping to change at page 29, line 39 ¶		skipping to change at page 29, line 39 ¶
	H3_STREAM_CREATION_ERROR; see Section 8.		H3_STREAM_CREATION_ERROR; see Section 8.
	Push Stream Header {		Push Stream Header {
	Stream Type (i) = 0x01,		Stream Type (i) = 0x01,
	Push ID (i),		Push ID (i),
	}		}
	Figure 2: Push Stream Header		Figure 2: Push Stream Header
	Each Push ID MUST only be used once in a push stream header. If a		Each Push ID MUST only be used once in a push stream header. If a
	push stream header includes a Push ID that was used in another push		client detects that a push stream header includes a Push ID that was
	stream header, the client MUST treat this as a connection error of		used in another push stream header, the client MUST treat this as a
	type H3_ID_ERROR; see Section 8.		connection error of type H3_ID_ERROR; see Section 8.
	6.2.3. Reserved Stream Types		6.2.3. Reserved Stream Types
	Stream types of the format "0x1f * N + 0x21" for non-negative integer		Stream types of the format "0x1f * N + 0x21" for non-negative integer
	values of N are reserved to exercise the requirement that unknown		values of N are reserved to exercise the requirement that unknown
	types be ignored. These streams have no semantics, and can be sent		types be ignored. These streams have no semantics, and can be sent
	when application-layer padding is desired. They MAY also be sent on		when application-layer padding is desired. They MAY also be sent on
	connections where no data is currently being transferred. Endpoints		connections where no data is currently being transferred. Endpoints
	MUST NOT consider these streams to have any meaning upon receipt.		MUST NOT consider these streams to have any meaning upon receipt.
	skipping to change at page 32, line 6 ¶		skipping to change at page 32, line 6 ¶
	see Section 10.8.		see Section 10.8.
	When a stream terminates cleanly, if the last frame on the stream was		When a stream terminates cleanly, if the last frame on the stream was
	truncated, this MUST be treated as a connection error of type		truncated, this MUST be treated as a connection error of type
	H3_FRAME_ERROR; see Section 8. Streams that terminate abruptly may		H3_FRAME_ERROR; see Section 8. Streams that terminate abruptly may
	be reset at any point in a frame.		be reset at any point in a frame.
	7.2. Frame Definitions		7.2. Frame Definitions
	7.2.1. DATA		7.2.1. DATA
	DATA frames (type=0x0) convey arbitrary, variable-length sequences of		DATA frames (type=0x00) convey arbitrary, variable-length sequences
	bytes associated with HTTP request or response content.		of bytes associated with HTTP request or response content.
	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 a control stream, the recipient MUST		a DATA frame is received on a control stream, the recipient MUST
	respond with a connection error of type H3_FRAME_UNEXPECTED; see		respond with a connection error of type H3_FRAME_UNEXPECTED; see
	Section 8.		Section 8.
	DATA Frame {		DATA Frame {
	Type (i) = 0x0,		Type (i) = 0x00,
	Length (i),		Length (i),
	Data (..),		Data (..),
	}		}
	Figure 4: DATA Frame		Figure 4: DATA Frame
	7.2.2. HEADERS		7.2.2. HEADERS
	The HEADERS frame (type=0x1) is used to carry an HTTP field section,		The HEADERS frame (type=0x01) is used to carry an HTTP field section,
	encoded using QPACK. See [QPACK] for more details.		encoded using QPACK. See [QPACK] for more details.
	HEADERS Frame {		HEADERS Frame {
	Type (i) = 0x1,		Type (i) = 0x01,
	Length (i),		Length (i),
	Encoded Field Section (..),		Encoded Field Section (..),
	}		}
	Figure 5: HEADERS Frame		Figure 5: HEADERS Frame
	HEADERS frames can only be sent on request or push streams. If a		HEADERS frames can only be sent on request or push streams. If a
	HEADERS frame is received on a control stream, the recipient MUST		HEADERS frame is received on a control stream, the recipient MUST
	respond with a connection error (Section 8) of type		respond with a connection error (Section 8) of type
	H3_FRAME_UNEXPECTED.		H3_FRAME_UNEXPECTED.
	7.2.3. CANCEL_PUSH		7.2.3. CANCEL_PUSH
	The CANCEL_PUSH frame (type=0x3) is used to request cancellation of a		The CANCEL_PUSH frame (type=0x03) is used to request cancellation of
	server push prior to the push stream being received. The CANCEL_PUSH		a server push prior to the push stream being received. The
	frame identifies a server push by Push ID (see Section 4.4), encoded		CANCEL_PUSH frame identifies a server push by Push ID (see
	as a variable-length integer.		Section 4.4), encoded as a variable-length integer.
	When a client sends CANCEL_PUSH, it is indicating that it does not		When a client sends CANCEL_PUSH, it is indicating that it does not
	wish to receive the promised resource. The server SHOULD abort		wish to receive the promised resource. The server SHOULD abort
	sending the resource, but the mechanism to do so depends on the state		sending the resource, but the mechanism to do so depends on the state
	of the corresponding push stream. If the server has not yet created		of the corresponding push stream. If the server has not yet created
	a push stream, it does not create one. If the push stream is open,		a push stream, it does not create one. If the push stream is open,
	the server SHOULD abruptly terminate that stream. If the push stream		the server SHOULD abruptly terminate that stream. If the push stream
	has already ended, the server MAY still abruptly terminate the stream		has already ended, the server MAY still abruptly terminate the stream
	or MAY take no action.		or MAY take no action.
	skipping to change at page 33, line 30 ¶		skipping to change at page 33, line 30 ¶
	stream could arrive after a client has sent a CANCEL_PUSH frame,		stream could arrive after a client has sent a CANCEL_PUSH frame,
	because a server might not have processed the CANCEL_PUSH. The		because a server might not have processed the CANCEL_PUSH. The
	client SHOULD abort reading the stream with an error code of		client SHOULD abort reading the stream with an error code of
	H3_REQUEST_CANCELLED.		H3_REQUEST_CANCELLED.
	A CANCEL_PUSH frame is sent on the control stream. Receiving a		A CANCEL_PUSH frame is sent on the control stream. Receiving 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 connection error of type H3_FRAME_UNEXPECTED.		treated as a connection error of type H3_FRAME_UNEXPECTED.
	CANCEL_PUSH Frame {		CANCEL_PUSH Frame {
	Type (i) = 0x3,		Type (i) = 0x03,
	Length (i),		Length (i),
	Push ID (i),		Push ID (i),
	}		}
	Figure 6: CANCEL_PUSH Frame		Figure 6: CANCEL_PUSH Frame
	The CANCEL_PUSH frame carries a Push ID encoded as a variable-length		The CANCEL_PUSH frame carries a Push ID encoded as a variable-length
	integer. The Push ID identifies the server push that is being		integer. The Push ID identifies the server push that is being
	cancelled; see Section 4.4. If a CANCEL_PUSH frame is received that		cancelled; see Section 4.4. If a CANCEL_PUSH frame is received that
	references a Push ID greater than currently allowed on the		references a Push ID greater than currently allowed on the
	skipping to change at page 34, line 7 ¶		skipping to change at page 34, line 7 ¶
	H3_ID_ERROR.		H3_ID_ERROR.
	If the client receives a CANCEL_PUSH frame, that frame might identify		If the client receives a CANCEL_PUSH frame, that frame might identify
	a Push ID that has not yet been mentioned by a PUSH_PROMISE frame due		a Push ID that has not yet been mentioned by a PUSH_PROMISE frame due
	to reordering. If a server receives a CANCEL_PUSH frame for a Push		to reordering. If a server receives a CANCEL_PUSH frame for a Push
	ID that has not yet been mentioned by a PUSH_PROMISE frame, this MUST		ID that has not yet been mentioned by a PUSH_PROMISE frame, this MUST
	be treated as a connection error of type H3_ID_ERROR.		be treated as a connection error of type H3_ID_ERROR.
	7.2.4. SETTINGS		7.2.4. SETTINGS
	The SETTINGS frame (type=0x4) conveys configuration parameters that		The SETTINGS frame (type=0x04) 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 frames always apply to an entire HTTP/3 connection, never a		SETTINGS frames always apply to an entire HTTP/3 connection, never a
	single stream. A SETTINGS frame MUST be sent as the first frame of		single stream. A SETTINGS frame MUST be sent as the first frame of
	each control stream (see Section 6.2.1) by each peer, and MUST NOT be		each control stream (see Section 6.2.1) by each peer, and MUST NOT be
	sent subsequently. If an endpoint receives a second SETTINGS frame		sent subsequently. If an endpoint receives a second SETTINGS frame
	skipping to change at page 35, line 11 ¶		skipping to change at page 35, line 11 ¶
	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 parameter consists of a setting identifier and a value, both		Each parameter consists of a setting identifier and a value, both
	encoded as QUIC variable-length integers.		encoded as QUIC variable-length integers.
	Setting {		Setting {
	Identifier (i),		Identifier (i),
	Value (i),		Value (i),
	}		}
	SETTINGS Frame {		SETTINGS Frame {
	Type (i) = 0x4,		Type (i) = 0x04,
	Length (i),		Length (i),
	Setting (..) ...,		Setting (..) ...,
	}		}
	Figure 7: SETTINGS Frame		Figure 7: SETTINGS Frame
	An implementation MUST ignore any parameter with an identifier it		An implementation MUST ignore any parameter with an identifier it
	does not understand.		does not understand.
	7.2.4.1. Defined SETTINGS Parameters		7.2.4.1. Defined SETTINGS Parameters
	The following settings are defined in HTTP/3:		The following settings are defined in HTTP/3:
	SETTINGS_MAX_FIELD_SECTION_SIZE (0x6): The default value is		SETTINGS_MAX_FIELD_SECTION_SIZE (0x06): The default value is
	unlimited. See Section 4.1.1.3 for usage.		unlimited. See Section 4.1.1.3 for usage.
	Setting identifiers of the format "0x1f * N + 0x21" for non-negative		Setting identifiers of the format "0x1f * N + 0x21" for non-negative
	integer values of N are reserved to exercise the requirement that		integer values of N are reserved to exercise the requirement that
	unknown identifiers be ignored. Such settings have no defined		unknown identifiers be ignored. Such settings have no defined
	meaning. Endpoints SHOULD include at least one such setting in their		meaning. Endpoints SHOULD include at least one such setting in their
	SETTINGS frame. Endpoints MUST NOT consider such settings to have		SETTINGS frame. Endpoints MUST NOT consider such settings to have
	any meaning upon receipt.		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
	skipping to change at page 37, line 12 ¶		skipping to change at page 37, line 12 ¶
	server accepts 0-RTT but then sends settings that are not compatible		server accepts 0-RTT but then sends settings that are not compatible
	with the previously specified settings, this MUST be treated as a		with the previously specified settings, this MUST be treated as a
	connection error of type H3_SETTINGS_ERROR. If a server accepts		connection error of type H3_SETTINGS_ERROR. If a server accepts
	0-RTT but then sends a SETTINGS frame that omits a setting value that		0-RTT but then sends a SETTINGS frame that omits a setting value that
	the client understands (apart from reserved setting identifiers) that		the client understands (apart from reserved setting identifiers) that
	was previously specified to have a non-default value, this MUST be		was previously specified to have a non-default value, this MUST be
	treated as a connection error of type H3_SETTINGS_ERROR.		treated as a connection error of type H3_SETTINGS_ERROR.
	7.2.5. PUSH_PROMISE		7.2.5. PUSH_PROMISE
	The PUSH_PROMISE frame (type=0x5) is used to carry a promised request		The PUSH_PROMISE frame (type=0x05) is used to carry a promised
	header section from server to client on a request stream, as in		request header section from server to client on a request stream, as
	HTTP/2.		in HTTP/2.
	PUSH_PROMISE Frame {		PUSH_PROMISE Frame {
	Type (i) = 0x5,		Type (i) = 0x05,
	Length (i),		Length (i),
	Push ID (i),		Push ID (i),
	Encoded Field Section (..),		Encoded Field Section (..),
	}		}
	Figure 8: PUSH_PROMISE Frame		Figure 8: PUSH_PROMISE Frame
	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
	skipping to change at page 38, line 23 ¶		skipping to change at page 38, line 23 ¶
	A client MUST NOT send a PUSH_PROMISE frame. A server MUST treat the		A client MUST NOT send a PUSH_PROMISE frame. A server MUST treat the
	receipt of a PUSH_PROMISE frame as a connection error of type		receipt of a PUSH_PROMISE frame as a connection error of type
	H3_FRAME_UNEXPECTED; see Section 8.		H3_FRAME_UNEXPECTED; see Section 8.
	See Section 4.4 for a description of the overall server push		See Section 4.4 for a description of the overall server push
	mechanism.		mechanism.
	7.2.6. GOAWAY		7.2.6. GOAWAY
	The GOAWAY frame (type=0x7) is used to initiate graceful shutdown of		The GOAWAY frame (type=0x07) is used to initiate graceful shutdown of
	an HTTP/3 connection by either endpoint. GOAWAY allows an endpoint		an HTTP/3 connection by either endpoint. GOAWAY allows an endpoint
	to stop accepting new requests or pushes while still finishing		to stop accepting new requests or pushes while still finishing
	processing of previously received requests and pushes. This enables		processing of previously received requests and pushes. This enables
	administrative actions, like server maintenance. GOAWAY by itself		administrative actions, like server maintenance. GOAWAY by itself
	does not close a connection.		does not close a connection.
	GOAWAY Frame {		GOAWAY Frame {
	Type (i) = 0x7,		Type (i) = 0x07,
	Length (i),		Length (i),
	Stream ID/Push ID (..),		Stream ID/Push ID (..),
	}		}
	Figure 9: GOAWAY Frame		Figure 9: GOAWAY Frame
	The GOAWAY frame is always sent on the control stream. In the server		The GOAWAY frame is always sent on the control stream. In the server
	to client direction, it carries a QUIC Stream ID for a client-		to client direction, it carries a QUIC Stream ID for a client-
	initiated bidirectional stream encoded as a variable-length integer.		initiated bidirectional stream encoded as a variable-length integer.
	A client MUST treat receipt of a GOAWAY frame containing a Stream ID		A client MUST treat receipt of a GOAWAY frame containing a Stream ID
	skipping to change at page 39, line 9 ¶		skipping to change at page 39, line 9 ¶
	The GOAWAY frame applies to the entire connection, not a specific		The GOAWAY frame applies to the entire connection, not a specific
	stream. A client MUST treat a GOAWAY frame on a stream other than		stream. A client MUST treat a GOAWAY frame on a stream other than
	the control stream as a connection error of type H3_FRAME_UNEXPECTED;		the control stream as a connection error of type H3_FRAME_UNEXPECTED;
	see Section 8.		see Section 8.
	See Section 5.2 for more information on the use of the GOAWAY frame.		See Section 5.2 for more information on the use of the GOAWAY frame.
	7.2.7. MAX_PUSH_ID		7.2.7. MAX_PUSH_ID
	The MAX_PUSH_ID frame (type=0xd) is used by clients to control the		The MAX_PUSH_ID frame (type=0x0d) 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 PUSH_PROMISE		maximum value for a Push ID that the server can use in PUSH_PROMISE
	and CANCEL_PUSH frames. Consequently, this also limits the number of		and CANCEL_PUSH frames. Consequently, this also limits the number of
	push streams that the server can initiate in addition to the limit		push streams that the server can initiate in addition to the limit
	maintained by the QUIC transport.		maintained by the QUIC transport.
	The MAX_PUSH_ID frame is always sent on the control stream. Receipt		The MAX_PUSH_ID frame is always sent on the control stream. Receipt
	of a MAX_PUSH_ID frame on any other stream MUST be treated as a		of a MAX_PUSH_ID frame on any other stream MUST be treated as a
	connection error of type H3_FRAME_UNEXPECTED.		connection error of type H3_FRAME_UNEXPECTED.
	skipping to change at page 39, line 31 ¶		skipping to change at page 39, line 31 ¶
	receipt of a MAX_PUSH_ID frame as a connection error of type		receipt of a MAX_PUSH_ID frame as a connection error of type
	H3_FRAME_UNEXPECTED.		H3_FRAME_UNEXPECTED.
	The maximum Push ID is unset when an HTTP/3 connection is created,		The maximum Push ID is unset when an HTTP/3 connection is created,
	meaning that a server cannot push until it receives a MAX_PUSH_ID		meaning that a server cannot push until it receives a MAX_PUSH_ID
	frame. A client that wishes to manage the number of promised server		frame. A client that wishes to manage the number of promised server
	pushes can increase the maximum Push ID by sending MAX_PUSH_ID frames		pushes can increase the maximum Push ID by sending MAX_PUSH_ID frames
	as the server fulfills or cancels server pushes.		as the server fulfills or cancels server pushes.
	MAX_PUSH_ID Frame {		MAX_PUSH_ID Frame {
	Type (i) = 0xd,		Type (i) = 0x0d,
	Length (i),		Length (i),
	Push ID (i),		Push ID (i),
	}		}
	Figure 10: MAX_PUSH_ID Frame		Figure 10: MAX_PUSH_ID Frame
	The MAX_PUSH_ID frame carries a single variable-length integer that		The MAX_PUSH_ID frame carries a single variable-length integer that
	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 4.4. A MAX_PUSH_ID frame cannot reduce the maximum Push		see Section 4.4. A MAX_PUSH_ID frame cannot reduce the maximum Push
	ID; receipt of a MAX_PUSH_ID frame that contains a smaller value than		ID; receipt of a MAX_PUSH_ID frame that contains a smaller value than
	skipping to change at page 41, line 11 ¶		skipping to change at page 41, line 11 ¶
	of an unknown error code MUST be treated as equivalent to		of an unknown error code MUST be treated as equivalent to
	H3_NO_ERROR. However, closing a stream can have other effects		H3_NO_ERROR. However, closing a stream can have other effects
	regardless of the error code; for example, see Section 4.1.		regardless of the error code; for example, see Section 4.1.
	8.1. HTTP/3 Error Codes		8.1. HTTP/3 Error Codes
	The following error codes are defined for use when abruptly		The following error codes are defined for use when abruptly
	terminating streams, aborting reading of streams, or immediately		terminating streams, aborting reading of streams, or immediately
	closing HTTP/3 connections.		closing HTTP/3 connections.
	H3_NO_ERROR (0x100): No error. This is used when the connection or		H3_NO_ERROR (0x0100): 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.
	H3_GENERAL_PROTOCOL_ERROR (0x101): Peer violated protocol		H3_GENERAL_PROTOCOL_ERROR (0x0101): Peer violated protocol
	requirements in a way that does not match a more specific error		requirements in a way that does not 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.
	H3_INTERNAL_ERROR (0x102): An internal error has occurred in the		H3_INTERNAL_ERROR (0x0102): An internal error has occurred in the
	HTTP stack.		HTTP stack.
	H3_STREAM_CREATION_ERROR (0x103): The endpoint detected that its		H3_STREAM_CREATION_ERROR (0x0103): The endpoint detected that its
	peer created a stream that it will not accept.		peer created a stream that it will not accept.
	H3_CLOSED_CRITICAL_STREAM (0x104): A stream required by the HTTP/3		H3_CLOSED_CRITICAL_STREAM (0x0104): A stream required by the HTTP/3
	connection was closed or reset.		connection was closed or reset.
	H3_FRAME_UNEXPECTED (0x105): A frame was received that was not		H3_FRAME_UNEXPECTED (0x0105): A frame was received that was not
	permitted in the current state or on the current stream.		permitted in the current state or on the current stream.
	H3_FRAME_ERROR (0x106): A frame that fails to satisfy layout		H3_FRAME_ERROR (0x0106): A frame that fails to satisfy layout
	requirements or with an invalid size was received.		requirements or with an invalid size was received.
	H3_EXCESSIVE_LOAD (0x107): The endpoint detected that its peer is		H3_EXCESSIVE_LOAD (0x0107): 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.
	H3_ID_ERROR (0x108): A Stream ID or Push ID was used incorrectly,		H3_ID_ERROR (0x0108): A Stream ID or Push ID was used incorrectly,
	such as exceeding a limit, reducing a limit, or being reused.		such as exceeding a limit, reducing a limit, or being reused.
	H3_SETTINGS_ERROR (0x109): An endpoint detected an error in the		H3_SETTINGS_ERROR (0x0109): An endpoint detected an error in the
	payload of a SETTINGS frame.		payload of a SETTINGS frame.
	H3_MISSING_SETTINGS (0x10a): No SETTINGS frame was received at the		H3_MISSING_SETTINGS (0x010a): No SETTINGS frame was received at the
	beginning of the control stream.		beginning of the control stream.
	H3_REQUEST_REJECTED (0x10b): A server rejected a request without		H3_REQUEST_REJECTED (0x010b): A server rejected a request without
	performing any application processing.		performing any application processing.
	H3_REQUEST_CANCELLED (0x10c): The request or its response (including		H3_REQUEST_CANCELLED (0x010c): The request or its response
	pushed response) is cancelled.		(including pushed response) is cancelled.
	H3_REQUEST_INCOMPLETE (0x10d): The client's stream terminated		H3_REQUEST_INCOMPLETE (0x010d): The client's stream terminated
	without containing a fully-formed request.		without containing a fully-formed request.
	H3_MESSAGE_ERROR (0x10e): An HTTP message was malformed and cannot		H3_MESSAGE_ERROR (0x010e): An HTTP message was malformed and cannot
	be processed.		be processed.
	H3_CONNECT_ERROR (0x10f): The TCP connection established in response		H3_CONNECT_ERROR (0x010f): The TCP connection established in
	to a CONNECT request was reset or abnormally closed.		response to a CONNECT request was reset or abnormally closed.
	H3_VERSION_FALLBACK (0x110): The requested operation cannot be		H3_VERSION_FALLBACK (0x0110): The requested operation cannot be
	served over HTTP/3. The peer should retry over HTTP/1.1.		served over HTTP/3. The peer should retry over HTTP/1.1.
	Error codes of the format "0x1f * N + 0x21" for non-negative integer		Error codes of the format "0x1f * N + 0x21" for non-negative integer
	values of N are reserved to exercise the requirement that unknown		values of N are reserved to exercise the requirement that unknown
	error codes be treated as equivalent to H3_NO_ERROR (Section 9).		error codes be treated as equivalent to H3_NO_ERROR (Section 9).
	Implementations SHOULD select an error code from this space with some		Implementations SHOULD select an error code from this space with some
	probability when they would have sent H3_NO_ERROR.		probability when they would have sent H3_NO_ERROR.
	9. Extensions to HTTP/3		9. Extensions to HTTP/3
	skipping to change at page 43, line 51 ¶		skipping to change at page 43, line 51 ¶
	The HTTP/3 field encoding allows the expression of names that are not		The HTTP/3 field encoding allows the expression of names that are not
	valid field names in the syntax used by HTTP (Section 5.1 of		valid field names in the syntax used by HTTP (Section 5.1 of
	[SEMANTICS]). Requests or responses containing invalid field names		[SEMANTICS]). Requests or responses containing invalid field names
	MUST be treated as malformed (Section 4.1.3). An intermediary		MUST be treated as malformed (Section 4.1.3). An intermediary
	therefore cannot translate an HTTP/3 request or response containing		therefore cannot translate an HTTP/3 request or response containing
	an invalid field name into an HTTP/1.1 message.		an invalid field name into an HTTP/1.1 message.
	Similarly, HTTP/3 can transport field values that are not valid.		Similarly, HTTP/3 can transport field values that are not valid.
	While most values that can be encoded will not alter field parsing,		While most values that can be encoded will not alter field parsing,
	carriage return (CR, ASCII 0xd), line feed (LF, ASCII 0xa), and the		carriage return (CR, ASCII 0x0d), line feed (LF, ASCII 0x0d), and the
	zero character (NUL, ASCII 0x0) might be exploited by an attacker if		zero character (NUL, ASCII 0x0d) might be exploited by an attacker if
	they are translated verbatim. Any request or response that contains		they are translated verbatim. Any request or response that contains
	a character not permitted in a field value MUST be treated as		a character not permitted in a field value MUST be treated as
	malformed (Section 4.1.3). Valid characters are defined by the		malformed (Section 4.1.3). Valid characters are defined by the
	"field-content" ABNF rule in Section 5.5 of [SEMANTICS].		"field-content" ABNF rule in Section 5.5 of [SEMANTICS].
	10.4. Cacheability of Pushed Responses		10.4. Cacheability of Pushed Responses
	Pushed responses do not have an explicit request from the client; the		Pushed responses do not have an explicit request from the client; the
	request is provided by the server in the PUSH_PROMISE frame.		request is provided by the server in the PUSH_PROMISE frame.
	skipping to change at page 48, line 43 ¶		skipping to change at page 48, line 43 ¶
	11. IANA Considerations		11. IANA Considerations
	This document registers a new ALPN protocol ID (Section 11.1) and		This document registers a new ALPN protocol ID (Section 11.1) and
	creates new registries that manage the assignment of codepoints in		creates new registries that manage the assignment of codepoints in
	HTTP/3.		HTTP/3.
	11.1. Registration of HTTP/3 Identification String		11.1. 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/3 in the "Application Layer Protocol Negotiation (ALPN) Protocol		HTTP/3 in the "Application-Layer Protocol Negotiation (ALPN) Protocol
	IDs" registry established in [RFC7301].		IDs" registry established in [RFC7301].
	The "h3" string identifies HTTP/3:		The "h3" string identifies HTTP/3:
	Protocol: HTTP/3		Protocol: HTTP/3
	Identification Sequence: 0x68 0x33 ("h3")		Identification Sequence: 0x68 0x33 ("h3")
	Specification: This document		Specification: This document
	skipping to change at page 50, line 8 ¶		skipping to change at page 50, line 8 ¶
	Specifications of frame types MUST include a description of the frame		Specifications of frame types MUST include a description of the frame
	layout and its semantics, including any parts of the frame that are		layout and its semantics, including any parts of the frame that are
	conditionally present.		conditionally present.
	The entries in Table 2 are registered by this document.		The entries in Table 2 are registered by this document.
	+--------------+-------+----------------+		+--------------+-------+----------------+
	| Frame Type | Value | Specification |		| Frame Type | Value | Specification |
	+--------------+-------+----------------+		+--------------+-------+----------------+
	| DATA | 0x0 | Section 7.2.1 |		| DATA | 0x00 | Section 7.2.1 |
	| | | |		| | | |
	| HEADERS | 0x1 | Section 7.2.2 |		| HEADERS | 0x01 | Section 7.2.2 |
	| | | |		| | | |
	| Reserved | 0x2 | N/A |		| Reserved | 0x02 | N/A |
	| | | |		| | | |
	| CANCEL_PUSH | 0x3 | Section 7.2.3 |		| CANCEL_PUSH | 0x03 | Section 7.2.3 |
	| | | |		| | | |
	| SETTINGS | 0x4 | Section 7.2.4 |		| SETTINGS | 0x04 | Section 7.2.4 |
	| | | |		| | | |
	| PUSH_PROMISE | 0x5 | Section 7.2.5 |		| PUSH_PROMISE | 0x05 | Section 7.2.5 |
	| | | |		| | | |
	| Reserved | 0x6 | N/A |		| Reserved | 0x06 | N/A |
	| | | |		| | | |
	| GOAWAY | 0x7 | Section 7.2.6 |		| GOAWAY | 0x07 | Section 7.2.6 |
	| | | |		| | | |
	| Reserved | 0x8 | N/A |		| Reserved | 0x08 | N/A |
	| | | |		| | | |
	| Reserved | 0x9 | N/A |		| Reserved | 0x09 | N/A |
	| | | |		| | | |
	| MAX_PUSH_ID | 0xd | Section 7.2.7 |		| MAX_PUSH_ID | 0x0d | Section 7.2.7 |
	+--------------+-------+----------------+		+--------------+-------+----------------+
	Table 2: Initial HTTP/3 Frame Types		Table 2: Initial HTTP/3 Frame Types
	Each code of the format "0x1f * N + 0x21" for non-negative integer		Each code of the format "0x1f * N + 0x21" for non-negative integer
	values of N (that is, 0x21, 0x40, ..., through 0x3ffffffffffffffe)		values of N (that is, 0x21, 0x40, ..., through 0x3ffffffffffffffe)
	MUST NOT be assigned by IANA and MUST NOT appear in the listing of		MUST NOT be assigned by IANA and MUST NOT appear in the listing of
	assigned values.		assigned values.
	11.2.2. Settings Parameters		11.2.2. Settings Parameters
	skipping to change at page 51, line 22 ¶		skipping to change at page 51, line 22 ¶
	name is optional.		name is optional.
	Default: The value of the setting unless otherwise indicated. A		Default: The value of the setting unless otherwise indicated. A
	default SHOULD be the most restrictive possible value.		default SHOULD be the most restrictive possible value.
	The entries in Table 3 are registered by this document.		The entries in Table 3 are registered by this document.
	+------------------------+-------+------------------+-----------+		+------------------------+-------+------------------+-----------+
	| Setting Name | Value | Specification | Default |		| Setting Name | Value | Specification | Default |
	+------------------------+-------+------------------+-----------+		+------------------------+-------+------------------+-----------+
	| Reserved | 0x0 | N/A | N/A |		| Reserved | 0x00 | N/A | N/A |
	| | | | |		| | | | |
	| Reserved | 0x2 | N/A | N/A |		| Reserved | 0x02 | N/A | N/A |
	| | | | |		| | | | |
	| Reserved | 0x3 | N/A | N/A |		| Reserved | 0x03 | N/A | N/A |
	| | | | |		| | | | |
	| Reserved | 0x4 | N/A | N/A |		| Reserved | 0x04 | N/A | N/A |
	| | | | |		| | | | |
	| Reserved | 0x5 | N/A | N/A |		| Reserved | 0x05 | N/A | N/A |
	| | | | |		| | | | |
	| MAX_FIELD_SECTION_SIZE | 0x6 | Section 7.2.4.1 | Unlimited |		| MAX_FIELD_SECTION_SIZE | 0x06 | Section 7.2.4.1 | Unlimited |
	+------------------------+-------+------------------+-----------+		+------------------------+-------+------------------+-----------+
	Table 3: Initial HTTP/3 Settings		Table 3: Initial HTTP/3 Settings
	Each code of the format "0x1f * N + 0x21" for non-negative integer		Each code of the format "0x1f * N + 0x21" for non-negative integer
	values of N (that is, 0x21, 0x40, ..., through 0x3ffffffffffffffe)		values of N (that is, 0x21, 0x40, ..., through 0x3ffffffffffffffe)
	MUST NOT be assigned by IANA and MUST NOT appear in the listing of		MUST NOT be assigned by IANA and MUST NOT appear in the listing of
	assigned values.		assigned values.
	11.2.3. Error Codes		11.2.3. Error Codes
	skipping to change at page 52, line 24 ¶		skipping to change at page 52, line 24 ¶
	this registry MUST include the following field:		this registry MUST include the following field:
	Name: A name for the error code.		Name: A name for the error code.
	Description: A brief description of the error code semantics.		Description: A brief description of the error code semantics.
	The entries in Table 4 are registered by this document. These error		The entries in Table 4 are registered by this document. These error
	codes were selected from the range that operates on a Specification		codes were selected from the range that operates on a Specification
	Required policy to avoid collisions with HTTP/2 error codes.		Required policy to avoid collisions with HTTP/2 error codes.
	+---------------------------+-------+---------------+---------------+		+---------------------------+--------+--------------+---------------+
	| Name | Value | Description | Specification |		| Name | Value | Description | Specification |
	+---------------------------+-------+---------------+---------------+		+---------------------------+--------+--------------+---------------+
	| H3_NO_ERROR | 0x100 | No error | Section 8.1 |		| H3_NO_ERROR | 0x0100 | No error | Section 8.1 |
	| | | | |		| | | | |
	| H3_GENERAL_PROTOCOL_ERROR | 0x101 | General | Section 8.1 |		| H3_GENERAL_PROTOCOL_ERROR | 0x0101 | General | Section 8.1 |
	| | | protocol | |		| | | protocol | |
	| | | error | |		| | | error | |
	| | | | |		| | | | |
	| H3_INTERNAL_ERROR | 0x102 | Internal | Section 8.1 |		| H3_INTERNAL_ERROR | 0x0102 | Internal | Section 8.1 |
	| | | error | |		| | | error | |
	| | | | |		| | | | |
	| H3_STREAM_CREATION_ERROR | 0x103 | Stream | Section 8.1 |		| H3_STREAM_CREATION_ERROR | 0x0103 | Stream | Section 8.1 |
	| | | creation | |		| | | creation | |
	| | | error | |		| | | error | |
	| | | | |		| | | | |
	| H3_CLOSED_CRITICAL_STREAM | 0x104 | Critical | Section 8.1 |		| H3_CLOSED_CRITICAL_STREAM | 0x0104 | Critical | Section 8.1 |
	| | | stream was | |		| | | stream was | |
	| | | closed | |		| | | closed | |
	| | | | |		| | | | |
	| H3_FRAME_UNEXPECTED | 0x105 | Frame not | Section 8.1 |		| H3_FRAME_UNEXPECTED | 0x0105 | Frame not | Section 8.1 |
	| | | permitted in | |		| | | permitted in | |
	| | | the current | |		| | | the current | |
	| | | state | |		| | | state | |
	| | | | |		| | | | |
	| H3_FRAME_ERROR | 0x106 | Frame | Section 8.1 |		| H3_FRAME_ERROR | 0x0106 | Frame | Section 8.1 |
	| | | violated | |		| | | violated | |
	| | | layout or | |		| | | layout or | |
	| | | size rules | |		| | | size rules | |
	| | | | |		| | | | |
	| H3_EXCESSIVE_LOAD | 0x107 | Peer | Section 8.1 |		| H3_EXCESSIVE_LOAD | 0x0107 | Peer | Section 8.1 |
	| | | generating | |		| | | generating | |
	| | | excessive | |		| | | excessive | |
	| | | load | |		| | | load | |
	| | | | |		| | | | |
	| H3_ID_ERROR | 0x108 | An identifier | Section 8.1 |		| H3_ID_ERROR | 0x0108 | An | Section 8.1 |
	| | | was used | |		| | | identifier | |
	| | | incorrectly | |		| | | was used | |
	| | | | |		| | | incorrectly | |
	| H3_SETTINGS_ERROR | 0x109 | SETTINGS | Section 8.1 |		| | | | |
	| | | frame | |		| H3_SETTINGS_ERROR | 0x0109 | SETTINGS | Section 8.1 |
	| | | contained | |		| | | frame | |
	| | | invalid | |		| | | contained | |
	| | | values | |		| | | invalid | |
	| | | | |		| | | values | |
	| H3_MISSING_SETTINGS | 0x10a | No SETTINGS | Section 8.1 |		| | | | |
	| | | frame | |		| H3_MISSING_SETTINGS | 0x010a | No SETTINGS | Section 8.1 |
	| | | received | |		| | | frame | |
	| | | | |		| | | received | |
	| H3_REQUEST_REJECTED | 0x10b | Request not | Section 8.1 |		| | | | |
	| | | processed | |		| H3_REQUEST_REJECTED | 0x010b | Request not | Section 8.1 |
	| | | | |		| | | processed | |
	| H3_REQUEST_CANCELLED | 0x10c | Data no | Section 8.1 |		| | | | |
	| | | longer needed | |		| H3_REQUEST_CANCELLED | 0x010c | Data no | Section 8.1 |
	| | | | |		| | | longer | |
	| H3_REQUEST_INCOMPLETE | 0x10d | Stream | Section 8.1 |		| | | needed | |
	| | | terminated | |		| | | | |
	| | | early | |		| H3_REQUEST_INCOMPLETE | 0x010d | Stream | Section 8.1 |
	| | | | |		| | | terminated | |
	| H3_MESSAGE_ERROR | 0x10e | Malformed | Section 8.1 |		| | | early | |
	| | | message | |		| | | | |
	| | | | |		| H3_MESSAGE_ERROR | 0x010e | Malformed | Section 8.1 |
	| H3_CONNECT_ERROR | 0x10f | TCP reset or | Section 8.1 |		| | | message | |
	| | | error on | |		| | | | |
	| | | CONNECT | |		| H3_CONNECT_ERROR | 0x010f | TCP reset or | Section 8.1 |
	| | | request | |		| | | error on | |
	| | | | |		| | | CONNECT | |
	| H3_VERSION_FALLBACK | 0x110 | Retry over | Section 8.1 |		| | | request | |
	| | | HTTP/1.1 | |		| | | | |
	+---------------------------+-------+---------------+---------------+		| H3_VERSION_FALLBACK | 0x0110 | Retry over | Section 8.1 |
			| | | HTTP/1.1 | |
			+---------------------------+--------+--------------+---------------+
	Table 4: Initial HTTP/3 Error Codes		Table 4: Initial HTTP/3 Error Codes
	Each code of the format "0x1f * N + 0x21" for non-negative integer		Each code of the format "0x1f * N + 0x21" for non-negative integer
	values of N (that is, 0x21, 0x40, ..., through 0x3ffffffffffffffe)		values of N (that is, 0x21, 0x40, ..., through 0x3ffffffffffffffe)
	MUST NOT be assigned by IANA and MUST NOT appear in the listing of		MUST NOT be assigned by IANA and MUST NOT appear in the listing of
	assigned values.		assigned values.
	11.2.4. Stream Types		11.2.4. Stream Types
	skipping to change at page 55, line 5 ¶		skipping to change at page 55, line 5 ¶
	assigned values.		assigned values.
	12. References		12. References
	12.1. Normative References		12.1. 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>.
	[CACHING] Fielding, R., Nottingham, M., and J. Reschke, "HTTP		[CACHING] Fielding, R. T., Nottingham, M., and J. Reschke, "HTTP
	Caching", draft-ietf-httpbis-cache-14 (work in progress),		Caching", draft-ietf-httpbis-cache-15 (work in progress),
	January 2021.		March 2021.
	[HTTP-REPLAY]		[HTTP-REPLAY]
	Thomson, M., Nottingham, M., and W. Tarreau, "Using Early		Thomson, M., Nottingham, M., and W. Tarreau, "Using Early
	Data in HTTP", RFC 8470, DOI 10.17487/RFC8470, September		Data in HTTP", RFC 8470, DOI 10.17487/RFC8470, September
	2018, <https://www.rfc-editor.org/info/rfc8470>.		2018, <https://www.rfc-editor.org/info/rfc8470>.
	[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-21 (work in progress).		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-34 (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 56, line 10 ¶		skipping to change at page 56, line 10 ¶
	[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for		[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
	Writing an IANA Considerations Section in RFCs", BCP 26,		Writing an IANA Considerations Section in RFCs", BCP 26,
	RFC 8126, DOI 10.17487/RFC8126, June 2017,		RFC 8126, DOI 10.17487/RFC8126, June 2017,
	<https://www.rfc-editor.org/info/rfc8126>.		<https://www.rfc-editor.org/info/rfc8126>.
	[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC		[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
	2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,		2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
	May 2017, <https://www.rfc-editor.org/info/rfc8174>.		May 2017, <https://www.rfc-editor.org/info/rfc8174>.
	[SEMANTICS]		[SEMANTICS]
	Fielding, R., Nottingham, M., and J. Reschke, "HTTP		Fielding, R. T., Nottingham, M., and J. Reschke, "HTTP
	Semantics", draft-ietf-httpbis-semantics-14 (work in		Semantics", draft-ietf-httpbis-semantics-15 (work in
	progress), January 2021.		progress), March 2021.
	[URI] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform		[URI] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
	Resource Identifier (URI): Generic Syntax", STD 66,		Resource Identifier (URI): Generic Syntax", STD 66,
	RFC 3986, DOI 10.17487/RFC3986, January 2005,		RFC 3986, DOI 10.17487/RFC3986, January 2005,
	<https://www.rfc-editor.org/info/rfc3986>.		<https://www.rfc-editor.org/info/rfc3986>.
	12.2. Informative References		12.2. Informative References
	[BREACH] Gluck, Y., Harris, N., and A. Prado, "BREACH: Reviving the		[BREACH] Gluck, Y., Harris, N., and A. Prado, "BREACH: Reviving the
	CRIME Attack", July 2013,		CRIME Attack", July 2013,
	skipping to change at page 56, line 35 ¶		skipping to change at page 56, line 35 ¶
	[DNS-TERMS]		[DNS-TERMS]
	Hoffman, P., Sullivan, A., and K. Fujiwara, "DNS		Hoffman, P., Sullivan, A., and K. Fujiwara, "DNS
	Terminology", BCP 219, RFC 8499, DOI 10.17487/RFC8499,		Terminology", BCP 219, RFC 8499, DOI 10.17487/RFC8499,
	January 2019, <https://www.rfc-editor.org/info/rfc8499>.		January 2019, <https://www.rfc-editor.org/info/rfc8499>.
	[HPACK] Peon, R. and H. Ruellan, "HPACK: Header Compression for		[HPACK] 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,
	<https://www.rfc-editor.org/info/rfc7541>.		<https://www.rfc-editor.org/info/rfc7541>.
	[HTTP11] Fielding, R., Nottingham, M., and J. Reschke, "HTTP/1.1",		[HTTP11] Fielding, R. T., Nottingham, M., and J. Reschke,
	draft-ietf-httpbis-messaging-14 (work in progress),		"HTTP/1.1", draft-ietf-httpbis-messaging-15 (work in
	January 2021.		progress), March 2021.
	[HTTP2] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext		[HTTP2] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext
	Transfer Protocol Version 2 (HTTP/2)", RFC 7540,		Transfer Protocol Version 2 (HTTP/2)", RFC 7540,
	DOI 10.17487/RFC7540, May 2015,		DOI 10.17487/RFC7540, May 2015,
	<https://www.rfc-editor.org/info/rfc7540>.		<https://www.rfc-editor.org/info/rfc7540>.
	[RFC6585] Nottingham, M. and R. Fielding, "Additional HTTP Status		[RFC6585] Nottingham, M. and R. Fielding, "Additional HTTP Status
	Codes", RFC 6585, DOI 10.17487/RFC6585, April 2012,		Codes", RFC 6585, DOI 10.17487/RFC6585, April 2012,
	<https://www.rfc-editor.org/info/rfc6585>.		<https://www.rfc-editor.org/info/rfc6585>.
	skipping to change at page 60, line 7 ¶		skipping to change at page 60, line 7 ¶
	space for flags as part of their frame payload.		space for flags as part of their frame payload.
	Other than these issues, frame type HTTP/2 extensions are typically		Other than these issues, 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/3. HTTP/3 extensions will not assume		control stream in HTTP/3. HTTP/3 extensions will not assume
	ordering, but would not be harmed by ordering, and are expected to be		ordering, but would not be harmed by ordering, and are expected to be
	portable to HTTP/2.		portable to HTTP/2.
	A.2.5. Comparison Between HTTP/2 and HTTP/3 Frame Types		A.2.5. Comparison Between HTTP/2 and HTTP/3 Frame Types
	DATA (0x0): Padding is not defined in HTTP/3 frames. See		DATA (0x00): Padding is not defined in HTTP/3 frames. See
	Section 7.2.1.		Section 7.2.1.
	HEADERS (0x1): The PRIORITY region of HEADERS is not defined in		HEADERS (0x01): The PRIORITY region of HEADERS is not defined in
	HTTP/3 frames. Padding is not defined in HTTP/3 frames. See		HTTP/3 frames. Padding is not defined in HTTP/3 frames. See
	Section 7.2.2.		Section 7.2.2.
	PRIORITY (0x2): As described in Appendix A.2.1, HTTP/3 does not		PRIORITY (0x02): As described in Appendix A.2.1, HTTP/3 does not
	provide a means of signaling priority.		provide a means of signaling priority.
	RST_STREAM (0x3): RST_STREAM frames do not exist in HTTP/3, since		RST_STREAM (0x03): RST_STREAM frames do not exist in HTTP/3, since
	QUIC provides stream lifecycle management. The same code point is		QUIC provides stream lifecycle management. The same code point is
	used for the CANCEL_PUSH frame (Section 7.2.3).		used for the CANCEL_PUSH frame (Section 7.2.3).
	SETTINGS (0x4): SETTINGS frames are sent only at the beginning of		SETTINGS (0x04): SETTINGS frames are sent only at the beginning of
	the connection. See Section 7.2.4 and Appendix A.3.		the connection. See Section 7.2.4 and Appendix A.3.
	PUSH_PROMISE (0x5): The PUSH_PROMISE frame does not reference a		PUSH_PROMISE (0x05): The PUSH_PROMISE frame does not reference a
	stream; instead the push stream references the PUSH_PROMISE frame		stream; instead the push stream references the PUSH_PROMISE frame
	using a Push ID. See Section 7.2.5.		using a Push ID. See Section 7.2.5.
	PING (0x6): PING frames do not exist in HTTP/3, as QUIC provides		PING (0x06): PING frames do not exist in HTTP/3, as QUIC provides
	equivalent functionality.		equivalent functionality.
	GOAWAY (0x7): GOAWAY does not contain an error code. In the client		GOAWAY (0x07): GOAWAY does not contain an error code. In the client
	to server direction, it carries a Push ID instead of a server		to server direction, it carries a Push ID instead of a server
	initiated stream ID. See Section 7.2.6.		initiated stream ID. See Section 7.2.6.
	WINDOW_UPDATE (0x8): WINDOW_UPDATE frames do not exist in HTTP/3,		WINDOW_UPDATE (0x08): WINDOW_UPDATE frames do not exist in HTTP/3,
	since QUIC provides flow control.		since QUIC provides flow control.
	CONTINUATION (0x9): CONTINUATION frames do not exist in HTTP/3;		CONTINUATION (0x09): CONTINUATION frames do not exist in HTTP/3;
	instead, larger HEADERS/PUSH_PROMISE frames than HTTP/2 are		instead, larger HEADERS/PUSH_PROMISE frames than HTTP/2 are
	permitted.		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/3 if still applicable. The IDs of frames defined		registered for HTTP/3 if still applicable. The IDs of frames defined
	in [HTTP2] have been reserved for simplicity. Note that the frame		in [HTTP2] have been reserved for simplicity. Note that the frame
	type space in HTTP/3 is substantially larger (62 bits versus 8 bits),		type space in HTTP/3 is substantially larger (62 bits versus 8 bits),
	so many HTTP/3 frame types have no equivalent HTTP/2 code points.		so many HTTP/3 frame types have no equivalent HTTP/2 code points.
	See Section 11.2.1.		See Section 11.2.1.
	skipping to change at page 61, line 21 ¶		skipping to change at page 61, line 21 ¶
	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/3. The		frame are superseded by QUIC transport parameters in HTTP/3. The
	HTTP-level setting that is retained in HTTP/3 has the same value as		HTTP-level setting that is retained in HTTP/3 has the same value as
	in HTTP/2. The superseded settings are reserved, and their receipt		in HTTP/2. The superseded settings are reserved, and their receipt
	is an error. See Section 7.2.4.1 for discussion of both the retained		is an error. See Section 7.2.4.1 for discussion of both the retained
	and reserved values.		and reserved values.
	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 (0x1): See [QPACK].		SETTINGS_HEADER_TABLE_SIZE (0x01): See [QPACK].
	SETTINGS_ENABLE_PUSH (0x2): This is removed in favor of the		SETTINGS_ENABLE_PUSH (0x02): This is removed in favor of the
	MAX_PUSH_ID frame, which provides a more granular control over		MAX_PUSH_ID frame, which provides a more granular control over
	server push. Specifying a setting with the identifier 0x2		server push. Specifying a setting with the identifier 0x02
	(corresponding to the SETTINGS_ENABLE_PUSH parameter) in the		(corresponding to the SETTINGS_ENABLE_PUSH parameter) in the
	HTTP/3 SETTINGS frame is an error.		HTTP/3 SETTINGS frame is an error.
	SETTINGS_MAX_CONCURRENT_STREAMS (0x3): QUIC controls the largest		SETTINGS_MAX_CONCURRENT_STREAMS (0x03): QUIC controls the largest
	open Stream ID as part of its flow control logic. Specifying a		open Stream ID as part of its flow control logic. Specifying a
	setting with the identifier 0x3 (corresponding to the		setting with the identifier 0x03 (corresponding to the
	SETTINGS_MAX_CONCURRENT_STREAMS parameter) in the HTTP/3 SETTINGS		SETTINGS_MAX_CONCURRENT_STREAMS parameter) in the HTTP/3 SETTINGS
	frame is an error.		frame is an error.
	SETTINGS_INITIAL_WINDOW_SIZE (0x4): QUIC requires both stream and		SETTINGS_INITIAL_WINDOW_SIZE (0x04): 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 a setting with the		initial transport handshake. Specifying a setting with the
	identifier 0x4 (corresponding to the SETTINGS_INITIAL_WINDOW_SIZE		identifier 0x04 (corresponding to the SETTINGS_INITIAL_WINDOW_SIZE
	parameter) in the HTTP/3 SETTINGS frame is an error.		parameter) in the HTTP/3 SETTINGS frame is an error.
	SETTINGS_MAX_FRAME_SIZE (0x5): This setting has no equivalent in		SETTINGS_MAX_FRAME_SIZE (0x05): This setting has no equivalent in
	HTTP/3. Specifying a setting with the identifier 0x5		HTTP/3. Specifying a setting with the identifier 0x05
	(corresponding to the SETTINGS_MAX_FRAME_SIZE parameter) in the		(corresponding to the SETTINGS_MAX_FRAME_SIZE parameter) in the
	HTTP/3 SETTINGS frame is an error.		HTTP/3 SETTINGS frame is an error.
	SETTINGS_MAX_HEADER_LIST_SIZE (0x6): This setting identifier has		SETTINGS_MAX_HEADER_LIST_SIZE (0x06): This setting identifier has
	been renamed SETTINGS_MAX_FIELD_SECTION_SIZE.		been renamed SETTINGS_MAX_FIELD_SECTION_SIZE.
	In HTTP/3, setting values are variable-length integers (6, 14, 30, or		In HTTP/3, setting values are variable-length integers (6, 14, 30, 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 that use the full 32-bit space. Settings		encoding for settings that use the full 32-bit space. Settings
	ported from HTTP/2 might choose to redefine their value to limit it		ported from HTTP/2 might choose to redefine their value to limit it
	to 30 bits for more efficient encoding, or to make use of the 62-bit		to 30 bits for more efficient encoding, or to make use of the 62-bit
	space if more than 30 bits are required.		space if more than 30 bits are required.
	skipping to change at page 62, line 27 ¶		skipping to change at page 62, line 27 ¶
	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, the differences between HTTP/2 and HTTP/3		HTTP/2 provides. However, the differences between HTTP/2 and HTTP/3
	mean that error codes are not directly portable between versions.		mean that error codes are not directly portable between versions.
	The HTTP/2 error codes defined in Section 7 of [HTTP2] logically map		The HTTP/2 error codes defined in Section 7 of [HTTP2] logically map
	to the HTTP/3 error codes as follows:		to the HTTP/3 error codes as follows:
	NO_ERROR (0x0): H3_NO_ERROR in Section 8.1.		NO_ERROR (0x00): H3_NO_ERROR in Section 8.1.
	PROTOCOL_ERROR (0x1): This is mapped to H3_GENERAL_PROTOCOL_ERROR		PROTOCOL_ERROR (0x01): This is mapped to H3_GENERAL_PROTOCOL_ERROR
	except in cases where more specific error codes have been defined.		except in cases where more specific error codes have been defined.
	Such cases include H3_FRAME_UNEXPECTED, H3_MESSAGE_ERROR, and		Such cases include H3_FRAME_UNEXPECTED, H3_MESSAGE_ERROR, and
	H3_CLOSED_CRITICAL_STREAM defined in Section 8.1.		H3_CLOSED_CRITICAL_STREAM defined in Section 8.1.
	INTERNAL_ERROR (0x2): H3_INTERNAL_ERROR in Section 8.1.		INTERNAL_ERROR (0x02): H3_INTERNAL_ERROR in Section 8.1.
	FLOW_CONTROL_ERROR (0x3): Not applicable, since QUIC handles flow		FLOW_CONTROL_ERROR (0x03): Not applicable, since QUIC handles flow
	control.		control.
	SETTINGS_TIMEOUT (0x4): Not applicable, since no acknowledgment of		SETTINGS_TIMEOUT (0x04): Not applicable, since no acknowledgment of
	SETTINGS is defined.		SETTINGS is defined.
	STREAM_CLOSED (0x5): Not applicable, since QUIC handles stream		STREAM_CLOSED (0x05): Not applicable, since QUIC handles stream
	management.		management.
	FRAME_SIZE_ERROR (0x6): H3_FRAME_ERROR error code defined in		FRAME_SIZE_ERROR (0x06): H3_FRAME_ERROR error code defined in
	Section 8.1.		Section 8.1.
	REFUSED_STREAM (0x7): H3_REQUEST_REJECTED (in Section 8.1) is used		REFUSED_STREAM (0x07): H3_REQUEST_REJECTED (in Section 8.1) is used
	to indicate that a request was not processed. Otherwise, not		to indicate that a request was not processed. Otherwise, not
	applicable because QUIC handles stream management.		applicable because QUIC handles stream management.
	CANCEL (0x8): H3_REQUEST_CANCELLED in Section 8.1.		CANCEL (0x08): H3_REQUEST_CANCELLED in Section 8.1.
	COMPRESSION_ERROR (0x9): Multiple error codes are defined in		COMPRESSION_ERROR (0x09): Multiple error codes are defined in
	[QPACK].		[QPACK].
	CONNECT_ERROR (0xa): H3_CONNECT_ERROR in Section 8.1.		CONNECT_ERROR (0x0a): H3_CONNECT_ERROR in Section 8.1.
	ENHANCE_YOUR_CALM (0xb): H3_EXCESSIVE_LOAD in Section 8.1.		ENHANCE_YOUR_CALM (0x0b): H3_EXCESSIVE_LOAD in Section 8.1.
	INADEQUATE_SECURITY (0xc): Not applicable, since QUIC is assumed to		INADEQUATE_SECURITY (0x0c): Not applicable, since QUIC is assumed to
	provide sufficient security on all connections.		provide sufficient security on all connections.
	HTTP_1_1_REQUIRED (0xd): H3_VERSION_FALLBACK in Section 8.1.		HTTP_1_1_REQUIRED (0x0d): H3_VERSION_FALLBACK in Section 8.1.
	Error codes need to be defined for HTTP/2 and HTTP/3 separately. See		Error codes need to be defined for HTTP/2 and HTTP/3 separately. See
	Section 11.2.3.		Section 11.2.3.
	A.4.1. Mapping Between HTTP/2 and HTTP/3 Errors		A.4.1. Mapping Between HTTP/2 and HTTP/3 Errors
	An intermediary that converts between HTTP/2 and HTTP/3 may encounter		An intermediary that converts between HTTP/2 and HTTP/3 may encounter
	error conditions from either upstream. It is useful to communicate		error conditions from either upstream. It is useful to communicate
	the occurrence of error to the downstream but error codes largely		the occurrence of error to the downstream but error codes largely
	reflect connection-local problems that generally do not make sense to		reflect connection-local problems that generally do not make sense to
	skipping to change at page 67, line 31 ¶		skipping to change at page 67, line 31 ¶
	* Describe malformed messages and their handling (#2410, #2764)		* Describe malformed messages and their handling (#2410, #2764)
	* Remove HTTP_PUSH_ALREADY_IN_CACHE error (#2812, #2813)		* Remove HTTP_PUSH_ALREADY_IN_CACHE error (#2812, #2813)
	* Refactor Push ID related errors (#2818, #2820)		* Refactor Push ID related errors (#2818, #2820)
	* Rationalize HTTP/3 stream creation errors (#2821, #2822)		* Rationalize HTTP/3 stream creation errors (#2821, #2822)
	B.14. Since draft-ietf-quic-http-19		B.14. Since draft-ietf-quic-http-19
	o SETTINGS_NUM_PLACEHOLDERS is 0x9 (#2443,#2530)		o SETTINGS_NUM_PLACEHOLDERS is 0x09 (#2443,#2530)
	o Non-zero bits in the Empty field of the PRIORITY frame MAY be		o Non-zero bits in the Empty field of the PRIORITY frame MAY be
	treated as an error (#2501)		treated as an error (#2501)
	B.15. Since draft-ietf-quic-http-18		B.15. Since draft-ietf-quic-http-18
	o Resetting streams following a GOAWAY is recommended, but not		o Resetting streams following a GOAWAY is recommended, but not
	required (#2256,#2457)		required (#2256,#2457)
	o Use variable-length integers throughout (#2437,#2233,#2253,#2275)		o Use variable-length integers throughout (#2437,#2233,#2253,#2275)
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