draft-ietf-rtcweb-overview-16.txt		draft-ietf-rtcweb-overview-17.txt
	Network Working Group H. Alvestrand		Network Working Group H. Alvestrand
	Internet-Draft Google		Internet-Draft Google
	Intended status: Standards Track November 14, 2016		Intended status: Standards Track February 17, 2017
	Expires: May 18, 2017		Expires: August 21, 2017
	Overview: Real Time Protocols for Browser-based Applications		Overview: Real Time Protocols for Browser-based Applications
	draft-ietf-rtcweb-overview-16		draft-ietf-rtcweb-overview-17
	Abstract		Abstract
	This document gives an overview and context of a protocol suite		This document gives an overview and context of a protocol suite
	intended for use with real-time applications that can be deployed in		intended for use with real-time applications that can be deployed in
	browsers - "real time communication on the Web".		browsers - "real time communication on the Web".
	It intends to serve as a starting and coordination point to make sure		It intends to serve as a starting and coordination point to make sure
	all the parts that are needed to achieve this goal are findable, and		all the parts that are needed to achieve this goal are findable, and
	that the parts that belong in the Internet protocol suite are fully		that the parts that belong in the Internet protocol suite are fully
	skipping to change at page 1, line 43 ¶		skipping to change at page 1, line 43 ¶
	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 May 18, 2017.		This Internet-Draft will expire on August 21, 2017.
	Copyright Notice		Copyright Notice
	Copyright (c) 2016 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
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	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
	skipping to change at page 3, line 11 ¶		skipping to change at page 3, line 11 ¶
	A.11. Changes from -06 to -07 . . . . . . . . . . . . . . . . . 21		A.11. Changes from -06 to -07 . . . . . . . . . . . . . . . . . 21
	A.12. Changes from -07 to -08 . . . . . . . . . . . . . . . . . 21		A.12. Changes from -07 to -08 . . . . . . . . . . . . . . . . . 21
	A.13. Changes from -08 to -09 . . . . . . . . . . . . . . . . . 21		A.13. Changes from -08 to -09 . . . . . . . . . . . . . . . . . 21
	A.14. Changes from -09 to -10 . . . . . . . . . . . . . . . . . 21		A.14. Changes from -09 to -10 . . . . . . . . . . . . . . . . . 21
	A.15. Changes from -10 to -11 . . . . . . . . . . . . . . . . . 22		A.15. Changes from -10 to -11 . . . . . . . . . . . . . . . . . 22
	A.16. Changes from -11 to -12 . . . . . . . . . . . . . . . . . 22		A.16. Changes from -11 to -12 . . . . . . . . . . . . . . . . . 22
	A.17. Changes from -12 to -13 . . . . . . . . . . . . . . . . . 22		A.17. Changes from -12 to -13 . . . . . . . . . . . . . . . . . 22
	A.18. Changes from -13 to -14 . . . . . . . . . . . . . . . . . 22		A.18. Changes from -13 to -14 . . . . . . . . . . . . . . . . . 22
	A.19. Changes from -14 to -15 . . . . . . . . . . . . . . . . . 22		A.19. Changes from -14 to -15 . . . . . . . . . . . . . . . . . 22
	A.20. Changes from -15 to -16 . . . . . . . . . . . . . . . . . 22		A.20. Changes from -15 to -16 . . . . . . . . . . . . . . . . . 22
			A.21. Changes from -16 to -17 . . . . . . . . . . . . . . . . . 23
	Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 23		Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 23
	1. Introduction		1. Introduction
	The Internet was, from very early in its lifetime, considered a		The Internet was, from very early in its lifetime, considered a
	possible vehicle for the deployment of real-time, interactive		possible vehicle for the deployment of real-time, interactive
	applications - with the most easily imaginable being audio		applications - with the most easily imaginable being audio
	conversations (aka "Internet telephony") and video conferencing.		conversations (aka "Internet telephony") and video conferencing.
	The first attempts to build this were dependent on special networks,		The first attempts to build this were dependent on special networks,
	skipping to change at page 4, line 35 ¶		skipping to change at page 4, line 35 ¶
	2.1. Goals of this document		2.1. Goals of this document
	The goal of the WebRTC protocol specification is to specify a set of		The goal of the WebRTC protocol specification is to specify a set of
	protocols that, if all are implemented, will allow an implementation		protocols that, if all are implemented, will allow an implementation
	to communicate with another implementation using audio, video and		to communicate with another implementation using audio, video and
	data sent along the most direct possible path between the		data sent along the most direct possible path between the
	participants.		participants.
	This document is intended to serve as the roadmap to the WebRTC		This document is intended to serve as the roadmap to the WebRTC
	specifications. It defines terms used by other pieces of		specifications. It defines terms used by other parts of the WebRTC
	specification, lists references to other specifications that don't		protocol specifications, lists references to other specifications
	need further elaboration in the WebRTC context, and gives pointers to		that don't need further elaboration in the WebRTC context, and gives
	other documents that form part of the WebRTC suite.		pointers to other documents that form part of the WebRTC suite.
	By reading this document and the documents it refers to, it should be		By reading this document and the documents it refers to, it should be
	possible to have all information needed to implement an WebRTC		possible to have all information needed to implement an WebRTC
	compatible implementation.		compatible implementation.
	2.2. Relationship between API and protocol		2.2. Relationship between API and protocol
	The total WebRTC effort consists of two pieces:		The total WebRTC effort consists of two major parts, each consisting
			of multiple documents:
	o A protocol specification, done in the IETF		o A protocol specification, done in the IETF
			o A Javascript API specification, defined in a series of W3C
	o A Javascript API specification, done in the W3C		documents
	[W3C.WD-webrtc-20120209][W3C.WD-mediacapture-streams-20120628]		[W3C.WD-webrtc-20120209][W3C.WD-mediacapture-streams-20120628]
	Together, these two specifications aim to provide an environment		Together, these two specifications aim to provide an environment
	where Javascript embedded in any page, viewed in any compatible		where Javascript embedded in any page, when suitably authorized by
	browser, when suitably authorized by its user, is able to set up		its user, is able to set up communication using audio, video and
	communication using audio, video and auxiliary data, where the		auxiliary data, as long as the browser supports this specification.
	browser environment does not constrain the types of application in		The browser environment does not constrain the types of application
	which this functionality can be used.		in which this functionality can be used.
	The protocol specification does not assume that all implementations		The protocol specification does not assume that all implementations
	implement this API; it is not intended to be necessary for		implement this API; it is not intended to be necessary for
	interoperation to know whether the entity one is communicating with		interoperation to know whether the entity one is communicating with
	is a browser or another device implementing this specification.		is a browser or another device implementing this specification.
	The goal of cooperation between the protocol specification and the		The goal of cooperation between the protocol specification and the
	API specification is that for all options and features of the		API specification is that for all options and features of the
	protocol specification, it should be clear which API calls to make to		protocol specification, it should be clear which API calls to make to
	exercise that option or feature; similarly, for any sequence of API		exercise that option or feature; similarly, for any sequence of API
	skipping to change at page 7, line 28 ¶		skipping to change at page 7, line 33 ¶
	API: Application Programming Interface - a specification of a set of		API: Application Programming Interface - a specification of a set of
	calls and events, usually tied to a programming language or an		calls and events, usually tied to a programming language or an
	abstract formal specification such as WebIDL, with its defined		abstract formal specification such as WebIDL, with its defined
	semantics.		semantics.
	Browser: Used synonymously with "Interactive User Agent" as defined		Browser: Used synonymously with "Interactive User Agent" as defined
	in the HTML specification [W3C.WD-html5-20110525]. See also		in the HTML specification [W3C.WD-html5-20110525]. See also
	"WebRTC User Agent".		"WebRTC User Agent".
			Data channel: An abstraction that allows data to be sent between
			WebRTC endpoints in the form of messages. Two endpoints can have
			multiple data channels between them.
	ICE Agent: An implementation of the Interactive Connectivty		ICE Agent: An implementation of the Interactive Connectivty
	Establishment (ICE) [RFC5245] protocol. An ICE Agent may also be		Establishment (ICE) [I-D.ietf-ice-rfc5245bis] protocol. An ICE
	an SDP Agent, but there exist ICE Agents that do not use SDP (for		Agent may also be an SDP Agent, but there exist ICE Agents that do
	instance those that use Jingle).		not use SDP (for instance those that use Jingle).
	Interactive: Communication between multiple parties, where the		Interactive: Communication between multiple parties, where the
	expectation is that an action from one party can cause a reaction		expectation is that an action from one party can cause a reaction
	by another party, and the reaction can be observed by the first		by another party, and the reaction can be observed by the first
	party, with the total time required for the action/reaction/		party, with the total time required for the action/reaction/
	observation is on the order of no more than hundreds of		observation is on the order of no more than hundreds of
	milliseconds.		milliseconds.
	Media: Audio and video content. Not to be confused with		Media: Audio and video content. Not to be confused with
	"transmission media" such as wires.		"transmission media" such as wires.
	skipping to change at page 8, line 14 ¶		skipping to change at page 8, line 22 ¶
	Real-time media: Media where generation of content and display of		Real-time media: Media where generation of content and display of
	content are intended to occur closely together in time (on the		content are intended to occur closely together in time (on the
	order of no more than hundreds of milliseconds). Real-time media		order of no more than hundreds of milliseconds). Real-time media
	can be used to support interactive communication.		can be used to support interactive communication.
	SDP Agent: The protocol implementation involved in the SDP offer/		SDP Agent: The protocol implementation involved in the SDP offer/
	answer exchange, as defined in [RFC3264] section 3.		answer exchange, as defined in [RFC3264] section 3.
	Signaling: Communication that happens in order to establish, manage		Signaling: Communication that happens in order to establish, manage
	and control media paths.		and control media paths and data paths.
	Signaling Path: The communication channels used between entities		Signaling Path: The communication channels used between entities
	participating in signaling to transfer signaling. There may be		participating in signaling to transfer signaling. There may be
	more entities in the signaling path than in the media path.		more entities in the signaling path than in the media path.
	NOTE: Where common definitions exist for these terms, those		NOTE: Where common definitions exist for these terms, those
	definitions should be used to the greatest extent possible.		definitions should be used to the greatest extent possible.
	3. Architecture and Functionality groups		3. Architecture and Functionality groups
	The model of real-time support for browser-based applications does		The model of real-time support for browser-based applications does
	not assume that the browser will contain all the functions that need		not assume that the browser will contain all the functions that need
	to be performed in order to have a function such as a telephone or a		to be performed in order to have a function such as a telephone or a
	video conferencing unit; the vision is that the browser will have the		video conferencing unit; the vision is that the browser will have the
	functions that are needed for a Web application, working in		functions that are needed for a Web application, working in
	conjunction with its backend servers, to implement these functions.		conjunction with its backend servers, to implement these functions.
	This means that two vital interfaces need specification: The		This means that two vital interfaces need specification: The
	protocols that browsers talk to each other, without any intervening		protocols that browsers use to talk to each other, without any
	servers, and the APIs that are offered for a Javascript application		intervening servers, and the APIs that are offered for a Javascript
	to take advantage of the browser's functionality.		application to take advantage of the browser's functionality.
	+------------------------+ On-the-wire		+------------------------+ On-the-wire
	| | Protocols		| | Protocols
	| Servers |--------->		| Servers |--------->
	| |		| |
	| |		| |
	+------------------------+		+------------------------+
	^		^
	|		|
	|		|
	| HTTP/		| HTTP/
	| Websockets		| WebSockets
	|		|
	|		|
	+----------------------------+		+----------------------------+
	| Javascript/HTML/CSS |		| Javascript/HTML/CSS |
	+----------------------------+		+----------------------------+
	Other ^ ^RTC		Other ^ ^RTC
	APIs | |APIs		APIs | |APIs
	+---|-----------------|------+		+---|-----------------|------+
	| | | |		| | | |
	| +---------+|		| +---------+|
	skipping to change at page 9, line 39 ¶		skipping to change at page 9, line 39 ¶
	| | ||		| | ||
	| | ||		| | ||
	| +---------+|		| +---------+|
	+---------------------|------+		+---------------------|------+
	|		|
	V		V
	Native OS Services		Native OS Services
	Figure 1: Browser Model		Figure 1: Browser Model
	Note that HTTP and Websockets are also offered to the Javascript		Note that HTTP and WebSockets are also offered to the Javascript
	application through browser APIs.		application through browser APIs.
	As for all protocol and API specifications, there is no restriction		As for all protocol and API specifications, there is no restriction
	that the protocols can only be used to talk to another browser; since		that the protocols can only be used to talk to another browser; since
	they are fully specified, any endpoint that implements the protocols		they are fully specified, any endpoint that implements the protocols
	faithfully should be able to interoperate with the application		faithfully should be able to interoperate with the application
	running in the browser.		running in the browser.
	A commonly imagined model of deployment is the one depicted below.		A commonly imagined model of deployment is the one depicted below.
	+-----------+ +-----------+		+-----------+ +-----------+
	| Web | | Web |		| Web | | Web |
	| | Signaling | |		| | Signaling | |
	| |-------------| |		| |-------------| |
	| Server | path | Server |		| Server | path | Server |
	| | | |		| | | |
	+-----------+ +-----------+		+-----------+ +-----------+
	/ \		/ \
	/ \ Application-defined		/ \ Application-defined
	/ \ over		/ \ over
	/ \ HTTP/Websockets		/ \ HTTP/WebSockets
	/ Application-defined over \		/ Application-defined over \
	/ HTTP/Websockets \		/ HTTP/WebSockets \
	/ \		/ \
	+-----------+ +-----------+		+-----------+ +-----------+
	|JS/HTML/CSS| |JS/HTML/CSS|		|JS/HTML/CSS| |JS/HTML/CSS|
	+-----------+ +-----------+		+-----------+ +-----------+
	+-----------+ +-----------+		+-----------+ +-----------+
	| | | |		| | | |
	| | | |		| | | |
	| Browser | ------------------------- | Browser |		| Browser | ------------------------- | Browser |
	| | Media path | |		| | Media path | |
	| | | |		| | | |
	skipping to change at page 11, line 4 ¶		skipping to change at page 11, line 4 ¶
	If the two Web servers are operated by different entities, the inter-		If the two Web servers are operated by different entities, the inter-
	server signaling mechanism needs to be agreed upon, either by		server signaling mechanism needs to be agreed upon, either by
	standardization or by other means of agreement. Existing protocols		standardization or by other means of agreement. Existing protocols
	(for example SIP [RFC3261] or XMPP [RFC6120]) could be used between		(for example SIP [RFC3261] or XMPP [RFC6120]) could be used between
	servers, while either a standards-based or proprietary protocol could		servers, while either a standards-based or proprietary protocol could
	be used between the browser and the web server.		be used between the browser and the web server.
	For example, if both operators' servers implement SIP, SIP could be		For example, if both operators' servers implement SIP, SIP could be
	used for communication between servers, along with either a		used for communication between servers, along with either a
	standardized signaling mechanism (e.g. SIP over Websockets) or a		standardized signaling mechanism (e.g. SIP over WebSockets) or a
	proprietary signaling mechanism used between the application running		proprietary signaling mechanism used between the application running
	in the browser and the web server. Similarly, if both operators'		in the browser and the web server. Similarly, if both operators'
	servers implement XMPP, XMPP could be used for communication between		servers implement XMPP, XMPP could be used for communication between
	XMPP servers, with either a standardized signaling mechanism (e.g.		XMPP servers, with either a standardized signaling mechanism (e.g.
	XMPP over Websockets or BOSH) or a proprietary signaling mechanism		XMPP over WebSockets or BOSH) or a proprietary signaling mechanism
	used between the application running in the browser and the web		used between the application running in the browser and the web
	server.		server.
	The choice of protocols, and definition of the translation between		The choice of protocols for client-server and inter-server
	them, is outside the scope of the WebRTC protocol suite described in		signalling, and definition of the translation between them, is
	the document.		outside the scope of the WebRTC protocol suite described in the
			document.
	The functionality groups that are needed in the browser can be		The functionality groups that are needed in the browser can be
	specified, more or less from the bottom up, as:		specified, more or less from the bottom up, as:
	o Data transport: TCP, UDP and the means to securely set up		o Data transport: TCP, UDP and the means to securely set up
	connections between entities, as well as the functions for		connections between entities, as well as the functions for
	deciding when to send data: Congestion management, bandwidth		deciding when to send data: Congestion management, bandwidth
	estimation and so on.		estimation and so on.
	o Data framing: RTP and other data formats that serve as containers,		o Data framing: RTP, SCTP and other data formats that serve as
	and their functions for data confidentiality and integrity.		containers, and their functions for data confidentiality and
			integrity.
	o Data formats: Codec specifications, format specifications and		o Data formats: Codec specifications, format specifications and
	functionality specifications for the data passed between systems.		functionality specifications for the data passed between systems.
	Audio and video codecs, as well as formats for data and document		Audio and video codecs, as well as formats for data and document
	sharing, belong in this category. In order to make use of data		sharing, belong in this category. In order to make use of data
	formats, a way to describe them, a session description, is needed.		formats, a way to describe them, a session description, is needed.
	o Connection management: Setting up connections, agreeing on data		o Connection management: Setting up connections, agreeing on data
	formats, changing data formats during the duration of a call; SIP		formats, changing data formats during the duration of a call; SIP
	and Jingle/XMPP belong in this category.		and Jingle/XMPP belong in this category.
	skipping to change at page 15, line 22 ¶		skipping to change at page 15, line 22 ¶
	possibly decide to revoke the permission for camera usage.		possibly decide to revoke the permission for camera usage.
	o Automatic gain control, if present, should normalize a speaking		o Automatic gain control, if present, should normalize a speaking
	voice into a reasonable dB range.		voice into a reasonable dB range.
	The requirements on WebRTC systems with regard to audio processing		The requirements on WebRTC systems with regard to audio processing
	are found in [I-D.ietf-rtcweb-audio]; the proposed API for control of		are found in [I-D.ietf-rtcweb-audio]; the proposed API for control of
	local devices are found in [W3C.WD-mediacapture-streams-20120628].		local devices are found in [W3C.WD-mediacapture-streams-20120628].
	WebRTC endpoints MUST implement the processing functions in		WebRTC endpoints MUST implement the processing functions in
	[I-D.ietf-rtcweb-audio]. (Together with the requirement inSection 6,		[I-D.ietf-rtcweb-audio]. (Together with the requirement in
	this means that WebRTC endpoints MUST implement the whole document.)		Section 6, this means that WebRTC endpoints MUST implement the whole
			document.)
	10. IANA Considerations		10. IANA Considerations
	This document makes no request of IANA.		This document makes no request of IANA.
	Note to RFC Editor: this section may be removed on publication as an		Note to RFC Editor: this section may be removed on publication as an
	RFC.		RFC.
	11. Security Considerations		11. Security Considerations
	skipping to change at page 16, line 26 ¶		skipping to change at page 16, line 28 ¶
	does not mean that others' contributions are less important.		does not mean that others' contributions are less important.
	Thanks to Cary Bran, Cullen Jennings, Colin Perkins, Magnus		Thanks to Cary Bran, Cullen Jennings, Colin Perkins, Magnus
	Westerlund and Joerg Ott, who offered technical contributions on		Westerlund and Joerg Ott, who offered technical contributions on
	various versions of the draft.		various versions of the draft.
	Thanks to Jonathan Rosenberg, Matthew Kaufman and others at Skype for		Thanks to Jonathan Rosenberg, Matthew Kaufman and others at Skype for
	the ASCII drawings in section 1.		the ASCII drawings in section 1.
	Thanks to Bjoern Hoehrmann, Colin Perkins, Colton Shields, Eric		Thanks to Bjoern Hoehrmann, Colin Perkins, Colton Shields, Eric
	Rescorla, Heath Matlock, Henry Sinnreich, Justin Uberti, Keith Drage		Rescorla, Heath Matlock, Henry Sinnreich, Justin Uberti, Keith Drage,
	and Simon Leinen for document review.		Magnus Westerlund, Olle E. Johansson and Simon Leinen for document
			review.
	13. References		13. References
	13.1. Normative References		13.1. Normative References
			[I-D.ietf-ice-rfc5245bis]
			Keranen, A., Holmberg, C., and J. Rosenberg, "Interactive
			Connectivity Establishment (ICE): A Protocol for Network
			Address Translator (NAT) Traversal", draft-ietf-ice-
			rfc5245bis-08 (work in progress), December 2016.
	[I-D.ietf-rtcweb-audio]		[I-D.ietf-rtcweb-audio]
	Valin, J. and C. Bran, "WebRTC Audio Codec and Processing		Valin, J. and C. Bran, "WebRTC Audio Codec and Processing
	Requirements", draft-ietf-rtcweb-audio-11 (work in		Requirements", draft-ietf-rtcweb-audio-11 (work in
	progress), April 2016.		progress), April 2016.
	[I-D.ietf-rtcweb-data-channel]		[I-D.ietf-rtcweb-data-channel]
	Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data		Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data
	Channels", draft-ietf-rtcweb-data-channel-13 (work in		Channels", draft-ietf-rtcweb-data-channel-13 (work in
	progress), January 2015.		progress), January 2015.
	[I-D.ietf-rtcweb-data-protocol]		[I-D.ietf-rtcweb-data-protocol]
	Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data Channel		Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data Channel
	Establishment Protocol", draft-ietf-rtcweb-data-		Establishment Protocol", draft-ietf-rtcweb-data-
	protocol-09 (work in progress), January 2015.		protocol-09 (work in progress), January 2015.
	[I-D.ietf-rtcweb-jsep]		[I-D.ietf-rtcweb-jsep]
	Uberti, J., Jennings, C., and E. Rescorla, "Javascript		Uberti, J., Jennings, C., and E. Rescorla, "Javascript
	Session Establishment Protocol", draft-ietf-rtcweb-jsep-17		Session Establishment Protocol", draft-ietf-rtcweb-jsep-18
	(work in progress), October 2016.		(work in progress), January 2017.
	[I-D.ietf-rtcweb-rtp-usage]		[I-D.ietf-rtcweb-rtp-usage]
	Perkins, C., Westerlund, M., and J. Ott, "Web Real-Time		Perkins, C., Westerlund, M., and J. Ott, "Web Real-Time
	Communication (WebRTC): Media Transport and Use of RTP",		Communication (WebRTC): Media Transport and Use of RTP",
	draft-ietf-rtcweb-rtp-usage-26 (work in progress), March		draft-ietf-rtcweb-rtp-usage-26 (work in progress), March
	2016.		2016.
	[I-D.ietf-rtcweb-security]		[I-D.ietf-rtcweb-security]
	Rescorla, E., "Security Considerations for WebRTC", draft-		Rescorla, E., "Security Considerations for WebRTC", draft-
	ietf-rtcweb-security-08 (work in progress), February 2015.		ietf-rtcweb-security-08 (work in progress), February 2015.
	skipping to change at page 17, line 43 ¶		skipping to change at page 18, line 5 ¶
	[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V.		[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V.
	Jacobson, "RTP: A Transport Protocol for Real-Time		Jacobson, "RTP: A Transport Protocol for Real-Time
	Applications", STD 64, RFC 3550, DOI 10.17487/RFC3550,		Applications", STD 64, RFC 3550, DOI 10.17487/RFC3550,
	July 2003, <http://www.rfc-editor.org/info/rfc3550>.		July 2003, <http://www.rfc-editor.org/info/rfc3550>.
	[RFC3711] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K.		[RFC3711] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K.
	Norrman, "The Secure Real-time Transport Protocol (SRTP)",		Norrman, "The Secure Real-time Transport Protocol (SRTP)",
	RFC 3711, DOI 10.17487/RFC3711, March 2004,		RFC 3711, DOI 10.17487/RFC3711, March 2004,
	<http://www.rfc-editor.org/info/rfc3711>.		<http://www.rfc-editor.org/info/rfc3711>.
	[RFC5245] Rosenberg, J., "Interactive Connectivity Establishment
	(ICE): A Protocol for Network Address Translator (NAT)
	Traversal for Offer/Answer Protocols", RFC 5245,
	DOI 10.17487/RFC5245, April 2010,
	<http://www.rfc-editor.org/info/rfc5245>.
	[W3C.WD-mediacapture-streams-20120628]		[W3C.WD-mediacapture-streams-20120628]
	Burnett, D. and A. Narayanan, "Media Capture and Streams",		Burnett, D. and A. Narayanan, "Media Capture and Streams",
	World Wide Web Consortium WD WD-mediacapture-streams-		World Wide Web Consortium WD WD-mediacapture-streams-
	20120628, June 2012, <http://www.w3.org/TR/2012/		20120628, June 2012, <http://www.w3.org/TR/2012/
	WD-mediacapture-streams-20120628>.		WD-mediacapture-streams-20120628>.
	[W3C.WD-webrtc-20120209]		[W3C.WD-webrtc-20120209]
	Bergkvist, A., Burnett, D., Jennings, C., and A.		Bergkvist, A., Burnett, D., Jennings, C., and A.
	Narayanan, "WebRTC 1.0: Real-time Communication Between		Narayanan, "WebRTC 1.0: Real-time Communication Between
	Browsers", World Wide Web Consortium WD WD-webrtc-		Browsers", World Wide Web Consortium WD WD-webrtc-
	skipping to change at page 23, line 5 ¶		skipping to change at page 23, line 5 ¶
	None. This is a "keepalive" update.		None. This is a "keepalive" update.
	A.19. Changes from -14 to -15		A.19. Changes from -14 to -15
	Changed "gateways" reference to point to the WG document.		Changed "gateways" reference to point to the WG document.
	A.20. Changes from -15 to -16		A.20. Changes from -15 to -16
	None. This is a "keepalive" publication.		None. This is a "keepalive" publication.
			A.21. Changes from -16 to -17
			Addressed review comments by Olle E. Johansson and Magnus Westerlund
	Author's Address		Author's Address
	Harald T. Alvestrand		Harald T. Alvestrand
	Google		Google
	Kungsbron 2		Kungsbron 2
	Stockholm 11122		Stockholm 11122
	Sweden		Sweden
	Email: harald@alvestrand.no		Email: harald@alvestrand.no
End of changes. 27 change blocks.
	47 lines changed or deleted		61 lines changed or added
This html diff was produced by rfcdiff 1.45. The latest version is available from http://tools.ietf.org/tools/rfcdiff/