draft-ietf-httpbis-early-hints-00.txt		draft-ietf-httpbis-early-hints-01.txt
	HTTP Working Group K. Oku		HTTP Working Group K. Oku
	Internet-Draft DeNA Co., Ltd.		Internet-Draft DeNA Co., Ltd.
	Intended status: Experimental February 8, 2017		Intended status: Experimental March 29, 2017
	Expires: August 12, 2017		Expires: September 30, 2017
	An HTTP Status Code for Indicating Hints		An HTTP Status Code for Indicating Hints
	draft-ietf-httpbis-early-hints-00		draft-ietf-httpbis-early-hints-01
	Abstract		Abstract
	This memo introduces an informational status code for HTTP that can		This memo introduces an informational status code for HTTP that can
	be used for indicating hints to help a client start making		be used for indicating hints to help a client start making
	preparations for processing the final response.		preparations for processing the final response.
	Note to Readers		Note to Readers
	Discussion of this draft takes place on the HTTP working group		Discussion of this draft takes place on the HTTP working group
	skipping to change at page 1, line 42 ¶		skipping to change at page 1, line 42 ¶
	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 August 12, 2017.		This Internet-Draft will expire on September 30, 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 20 ¶		skipping to change at page 2, line 20 ¶
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	1.1. Notational Conventions . . . . . . . . . . . . . . . . . 3		1.1. Notational Conventions . . . . . . . . . . . . . . . . . 3
	2. 103 Early Hints . . . . . . . . . . . . . . . . . . . . . . . 3		2. 103 Early Hints . . . . . . . . . . . . . . . . . . . . . . . 3
	3. Security Considerations . . . . . . . . . . . . . . . . . . . 3		3. Security Considerations . . . . . . . . . . . . . . . . . . . 4
	4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4		4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
	5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4		5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
	6. References . . . . . . . . . . . . . . . . . . . . . . . . . 4		6. Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
	6.1. Normative References . . . . . . . . . . . . . . . . . . 4		6.1. Since draft-ietf-httpbis-early-hints-00 . . . . . . . . . 4
	6.2. Informative References . . . . . . . . . . . . . . . . . 5		7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
			7.1. Normative References . . . . . . . . . . . . . . . . . . 5
			7.2. Informative References . . . . . . . . . . . . . . . . . 5
	Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5		Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5
	1. Introduction		1. Introduction
	Most if not all of the web pages processed by a web browser contain		Most if not all of the web pages processed by a web browser contain
	links to external resources that need to be fetched prior to		links to external resources that need to be fetched prior to
	rendering the documents. Therefore, it is beneficial to send such		rendering the documents. Therefore, it is beneficial to send such
	links as early as possible in order to minimize the time spent until		links as early as possible in order to minimize the time spent until
	the browser becomes possible to render the document. Link header of		the browser becomes possible to render the document. Link header of
	type "preload" ([Preload]) can be used to indicate such links within		type "preload" ([Preload]) can be used to indicate such links within
	skipping to change at page 3, line 39 ¶		skipping to change at page 3, line 43 ¶
	A server MUST NOT include Content-Length, Transfer-Encoding, or any		A server MUST NOT include Content-Length, Transfer-Encoding, or any
	hop-by-hop headers ([RFC7230], section 6.1) in the informational		hop-by-hop headers ([RFC7230], section 6.1) in the informational
	response using the status code.		response using the status code.
	A client MAY speculatively evaluate the headers included in the		A client MAY speculatively evaluate the headers included in the
	informational response while waiting for the final response. For		informational response while waiting for the final response. For
	example, a client may recognize the link header of type preload and		example, a client may recognize the link header of type preload and
	start fetching the resource. However, the evaluation MUST NOT affect		start fetching the resource. However, the evaluation MUST NOT affect
	how the final response is processed; the client must behave as if it		how the final response is processed; the client must behave as if it
	had not seen the informational response.		had not seen the informational response. A client MUST NOT process
			the headers included in the response as if they belonged to the
			informational response.
	An intermediary MAY drop the informational response. It MAY send		An intermediary MAY drop the informational response. It MAY send
	HTTP/2 ([RFC7540]) push responses using the information found in the		HTTP/2 ([RFC7540]) push responses using the information found in the
	informational response.		informational response.
	3. Security Considerations		3. Security Considerations
	Clients may have issues handling Early Hints, since informational		Clients may have issues handling Early Hints, since informational
	response is rarely used for requests not including an Expect header		response is rarely used for requests not including an Expect header
	([RFC7231], section 5.1.1).		([RFC7231], section 5.1.1).
	skipping to change at page 4, line 36 ¶		skipping to change at page 4, line 42 ¶
	o Description: Early Hints		o Description: Early Hints
	o Specification: this document		o Specification: this document
	5. Acknowledgements		5. Acknowledgements
	Thanks to Tatsuhiro Tsujikawa for coming up with the idea of sending		Thanks to Tatsuhiro Tsujikawa for coming up with the idea of sending
	the link headers using an informational response.		the link headers using an informational response.
	6. References		6. Changes
	6.1. Normative References		6.1. Since draft-ietf-httpbis-early-hints-00
			o Forbid processing the headers of a 103 response as part of the
			informational response.
			7. References
			7.1. Normative References
	[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,
	<http://www.rfc-editor.org/info/rfc2119>.		<http://www.rfc-editor.org/info/rfc2119>.
	[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer		[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
	Protocol (HTTP/1.1): Message Syntax and Routing",		Protocol (HTTP/1.1): Message Syntax and Routing",
	RFC 7230, DOI 10.17487/RFC7230, June 2014,		RFC 7230, DOI 10.17487/RFC7230, June 2014,
	<http://www.rfc-editor.org/info/rfc7230>.		<http://www.rfc-editor.org/info/rfc7230>.
	skipping to change at page 5, line 15 ¶		skipping to change at page 5, line 29 ¶
	[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer		[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
	Protocol (HTTP/1.1): Semantics and Content", RFC 7231,		Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
	DOI 10.17487/RFC7231, June 2014,		DOI 10.17487/RFC7231, June 2014,
	<http://www.rfc-editor.org/info/rfc7231>.		<http://www.rfc-editor.org/info/rfc7231>.
	[RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext		[RFC7540] 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,
	<http://www.rfc-editor.org/info/rfc7540>.		<http://www.rfc-editor.org/info/rfc7540>.
	6.2. Informative References		7.2. Informative References
	[Preload] Grigorik, I., "Preload", September 2016,		[Preload] Grigorik, I., "Preload", September 2016,
	<https://w3c.github.io/preload/>.		<https://w3c.github.io/preload/>.
	Author's Address		Author's Address
	Kazuho Oku		Kazuho Oku
	DeNA Co., Ltd.		DeNA Co., Ltd.
	Email: kazuhooku@gmail.com		Email: kazuhooku@gmail.com
End of changes. 9 change blocks.
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