draft-ietf-mmusic-data-channel-sdpneg-07.txt		draft-ietf-mmusic-data-channel-sdpneg-08.txt
	MMUSIC K. Drage, Ed.		MMUSIC K. Drage, Ed.
	Internet-Draft M. Makaraju		Internet-Draft M. Makaraju
	Intended status: Standards Track J. Stoetzer-Bradler		Intended status: Standards Track J. Stoetzer-Bradler
	Expires: June 2, 2016 Alcatel-Lucent		Expires: August 20, 2016 Nokia
	R. Ejzak		R. Ejzak
	J. Marcon		J. Marcon
	Unaffiliated		Unaffiliated
	November 30, 2015		February 17, 2016
	SDP-based Data Channel Negotiation		SDP-based Data Channel Negotiation
	draft-ietf-mmusic-data-channel-sdpneg-07		draft-ietf-mmusic-data-channel-sdpneg-08
	Abstract		Abstract
	The Real-Time Communication in WEB-browsers (RTCWeb) working group is		The Real-Time Communication in WEB-browsers (RTCWeb) working group is
	charged to provide protocols to support direct interactive rich		charged to provide protocols to support direct interactive rich
	communications using audio, video, and data between two peers' web-		communications using audio, video, and data between two peers' web-
	browsers. For the support of data communication, the RTCWeb working		browsers. For the support of data communication, the RTCWeb working
	group has in particular defined the concept of bi-directional data		group has in particular defined the concept of bi-directional data
	channels over SCTP (Stream Control Transmission Protocol), where each		channels over SCTP (Stream Control Transmission Protocol), where each
	data channel might be used to transport other protocols, called		data channel might be used to transport other protocols, called
	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 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 June 2, 2016.		This Internet-Draft will expire on August 20, 2016.
	Copyright Notice		Copyright Notice
	Copyright (c) 2015 IETF Trust and the persons identified as the		Copyright (c) 2016 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 2, line 35		skipping to change at page 2, line 35
	3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4		3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
	4. Applicability Statement . . . . . . . . . . . . . . . . . . . 5		4. Applicability Statement . . . . . . . . . . . . . . . . . . . 5
	5. SDP Offer/Answer Negotiation . . . . . . . . . . . . . . . . 5		5. SDP Offer/Answer Negotiation . . . . . . . . . . . . . . . . 5
	5.1. SDP Syntax . . . . . . . . . . . . . . . . . . . . . . . 5		5.1. SDP Syntax . . . . . . . . . . . . . . . . . . . . . . . 5
	5.1.1. SDP Attribute for Data Channel Parameter Negotiation 5		5.1.1. SDP Attribute for Data Channel Parameter Negotiation 5
	5.1.1.1. dcmap Attribute . . . . . . . . . . . . . . . . . 6		5.1.1.1. dcmap Attribute . . . . . . . . . . . . . . . . . 6
	5.1.1.2. dcmap Multiplexing Category . . . . . . . . . . . 7		5.1.1.2. dcmap Multiplexing Category . . . . . . . . . . . 7
	5.1.1.3. dcmap-stream-id Parameter . . . . . . . . . . . . 8		5.1.1.3. dcmap-stream-id Parameter . . . . . . . . . . . . 8
	5.1.1.4. label Parameter . . . . . . . . . . . . . . . . . 8		5.1.1.4. label Parameter . . . . . . . . . . . . . . . . . 8
	5.1.1.5. subprotocol Parameter . . . . . . . . . . . . . . 8		5.1.1.5. subprotocol Parameter . . . . . . . . . . . . . . 8
	5.1.1.6. max-retr Parameter . . . . . . . . . . . . . . . 8		5.1.1.6. max-retr Parameter . . . . . . . . . . . . . . . 9
	5.1.1.7. max-time Parameter . . . . . . . . . . . . . . . 9		5.1.1.7. max-time Parameter . . . . . . . . . . . . . . . 9
	5.1.1.8. ordered Parameter . . . . . . . . . . . . . . . . 9		5.1.1.8. ordered Parameter . . . . . . . . . . . . . . . . 9
	5.1.1.9. priority Parameter . . . . . . . . . . . . . . . 9		5.1.1.9. priority Parameter . . . . . . . . . . . . . . . 9
	5.1.2. Other Media Level Attributes . . . . . . . . . . . . 9		5.1.2. Other Media Level Attributes . . . . . . . . . . . . 9
	5.1.2.1. dcsa Attribute . . . . . . . . . . . . . . . . . 10		5.1.2.1. dcsa Attribute . . . . . . . . . . . . . . . . . 10
	5.1.2.2. dcsa Multiplexing Category . . . . . . . . . . . 11		5.1.2.2. dcsa Multiplexing Category . . . . . . . . . . . 11
	5.2. Procedures . . . . . . . . . . . . . . . . . . . . . . . 11		5.2. Procedures . . . . . . . . . . . . . . . . . . . . . . . 11
	5.2.1. Managing Stream Identifiers . . . . . . . . . . . . . 11		5.2.1. Managing Stream Identifiers . . . . . . . . . . . . . 12
	5.2.2. Negotiating Data Channel Parameters . . . . . . . . . 12		5.2.2. Negotiating Data Channel Parameters . . . . . . . . . 12
	5.2.3. Opening a Data Channel . . . . . . . . . . . . . . . 13		5.2.3. Opening a Data Channel . . . . . . . . . . . . . . . 13
	5.2.4. Closing a Data Channel . . . . . . . . . . . . . . . 15		5.2.4. Closing a Data Channel . . . . . . . . . . . . . . . 15
	5.2.5. Various SDP Offer/Answer Scenarios and Considerations 16		5.2.5. Various SDP Offer/Answer Scenarios and Considerations 16
	6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 17		6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 17
	7. Security Considerations . . . . . . . . . . . . . . . . . . . 19		7. Security Considerations . . . . . . . . . . . . . . . . . . . 20
	8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19		8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
	8.1. Subprotocol Identifiers . . . . . . . . . . . . . . . . . 19		8.1. Subprotocol Identifiers . . . . . . . . . . . . . . . . . 20
	8.2. New SDP Attributes . . . . . . . . . . . . . . . . . . . 20		8.2. New SDP Attributes . . . . . . . . . . . . . . . . . . . 21
	8.2.1. dcmap . . . . . . . . . . . . . . . . . . . . . . . . 20		8.2.1. dcmap . . . . . . . . . . . . . . . . . . . . . . . . 21
	8.2.2. dcsa . . . . . . . . . . . . . . . . . . . . . . . . 20		8.2.2. dcsa . . . . . . . . . . . . . . . . . . . . . . . . 21
	9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 21		9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 22
	10. CHANGE LOG . . . . . . . . . . . . . . . . . . . . . . . . . 21		10. CHANGE LOG . . . . . . . . . . . . . . . . . . . . . . . . . 22
	10.1. Changes against 'draft-ietf-mmusic-data-channel-		10.1. Changes against 'draft-ietf-mmusic-data-channel-
	sdpneg-06' . . . . . . . . . . . . . . . . . . . . . . . 21		sdpneg-07' . . . . . . . . . . . . . . . . . . . . . . . 22
	10.2. Changes against 'draft-ietf-mmusic-data-channel-		10.2. Changes against 'draft-ietf-mmusic-data-channel-
	sdpneg-05' . . . . . . . . . . . . . . . . . . . . . . . 21		sdpneg-06' . . . . . . . . . . . . . . . . . . . . . . . 22
	10.3. Changes against 'draft-ietf-mmusic-data-channel-		10.3. Changes against 'draft-ietf-mmusic-data-channel-
	sdpneg-04' . . . . . . . . . . . . . . . . . . . . . . . 22		sdpneg-05' . . . . . . . . . . . . . . . . . . . . . . . 23
	10.4. Changes against 'draft-ietf-mmusic-data-channel-		10.4. Changes against 'draft-ietf-mmusic-data-channel-
	sdpneg-03' . . . . . . . . . . . . . . . . . . . . . . . 23		sdpneg-04' . . . . . . . . . . . . . . . . . . . . . . . 23
	10.5. Changes against 'draft-ietf-mmusic-data-channel-		10.5. Changes against 'draft-ietf-mmusic-data-channel-
	sdpneg-02' . . . . . . . . . . . . . . . . . . . . . . . 24		sdpneg-03' . . . . . . . . . . . . . . . . . . . . . . . 24
	10.6. Changes against 'draft-ietf-mmusic-data-channel-		10.6. Changes against 'draft-ietf-mmusic-data-channel-
	sdpneg-01' . . . . . . . . . . . . . . . . . . . . . . . 25		sdpneg-02' . . . . . . . . . . . . . . . . . . . . . . . 25
	10.7. Changes against 'draft-ietf-mmusic-data-channel-		10.7. Changes against 'draft-ietf-mmusic-data-channel-
	sdpneg-00' . . . . . . . . . . . . . . . . . . . . . . . 27		sdpneg-01' . . . . . . . . . . . . . . . . . . . . . . . 26
	10.8. Changes against 'draft-ejzak-mmusic-data-channel-		10.8. Changes against 'draft-ietf-mmusic-data-channel-
	sdpneg-02' . . . . . . . . . . . . . . . . . . . . . . . 30		sdpneg-00' . . . . . . . . . . . . . . . . . . . . . . . 29
	10.9. Changes against '-01' . . . . . . . . . . . . . . . . . 31		10.9. Changes against 'draft-ejzak-mmusic-data-channel-
	10.10. Changes against '-00' . . . . . . . . . . . . . . . . . 31		sdpneg-02' . . . . . . . . . . . . . . . . . . . . . . . 31
	11. References . . . . . . . . . . . . . . . . . . . . . . . . . 32		10.10. Changes against '-01' . . . . . . . . . . . . . . . . . 32
	11.1. Normative References . . . . . . . . . . . . . . . . . . 32		10.11. Changes against '-00' . . . . . . . . . . . . . . . . . 33
	11.2. Informative References . . . . . . . . . . . . . . . . . 32		11. References . . . . . . . . . . . . . . . . . . . . . . . . . 33
			11.1. Normative References . . . . . . . . . . . . . . . . . . 33
			11.2. Informative References . . . . . . . . . . . . . . . . . 34
	Appendix A. Generic Data Channel Negotiation Aspects When Not		Appendix A. Generic Data Channel Negotiation Aspects When Not
	Using DCEP . . . . . . . . . . . . . . . . . . . . . 33		Using DCEP . . . . . . . . . . . . . . . . . . . . . 34
	A.1. Stream Identifier Numbering . . . . . . . . . . . . . . . 34		A.1. Stream Identifier Numbering . . . . . . . . . . . . . . . 35
	A.2. Generic Data Channel Negotiation Not Using DCEP . . . . . 34		A.2. Generic Data Channel Negotiation Not Using DCEP . . . . . 36
	A.2.1. Overview . . . . . . . . . . . . . . . . . . . . . . 34		A.2.1. Overview . . . . . . . . . . . . . . . . . . . . . . 36
	A.2.2. Opening a Data Channel . . . . . . . . . . . . . . . 35		A.2.2. Opening a Data Channel . . . . . . . . . . . . . . . 36
	A.2.3. Closing a Data Channel . . . . . . . . . . . . . . . 36		A.2.3. Closing a Data Channel . . . . . . . . . . . . . . . 37
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 36		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 37
	1. Introduction		1. Introduction
	The RTCWeb working group has defined the concept of bi-directional		The RTCWeb working group has defined the concept of bi-directional
	data channels running on top of SCTP/DTLS (SCTP over the Datagram		data channels running on top of SCTP/DTLS (SCTP over the Datagram
	Transport Layer Security protocol). RTCWeb allows applications to		Transport Layer Security protocol). RTCWeb allows applications to
	use data channels. RTCWeb defines an in-band DCEP, however other in-		use data channels. RTCWeb defines an in-band DCEP, however other in-
	band or out-of-band protocols may be used for establishing data		band or out-of-band protocols may be used for establishing data
	channels. Each data channel consists of paired SCTP streams sharing		channels. Each data channel consists of paired SCTP streams sharing
	the same SCTP Stream Identifier. Data channels are created by		the same SCTP Stream Identifier. Data channels are created by
	skipping to change at page 10, line 9		skipping to change at page 10, line 13
	defined for or applied to the subprotocol in use. Each of these		defined for or applied to the subprotocol in use. Each of these
	attributes is represented by one new attribute line, and it includes		attributes is represented by one new attribute line, and it includes
	the contents of a media-level SDP attribute already defined for use		the contents of a media-level SDP attribute already defined for use
	with this (sub)protocol in another IETF (Internet Engineering Task		with this (sub)protocol in another IETF (Internet Engineering Task
	Force) document. Subprotocol specific attributes MAY also be defined		Force) document. Subprotocol specific attributes MAY also be defined
	for exclusive use with data channel transport, but SHOULD use the		for exclusive use with data channel transport, but SHOULD use the
	same syntax described here for other subprotocol related attributes.		same syntax described here for other subprotocol related attributes.
	5.1.2.1. dcsa Attribute		5.1.2.1. dcsa Attribute
	Each subprotocol related SDP attribute that would normally be used to		Each SDP attribute, related to the subprotocol, that would normally
	negotiate the subprotocol using SDP is replaced with an attribute of		be used to negotiate the subprotocol using SDP is replaced with an
	the form "a=dcsa:stream-id original-attribute", where dcsa stands for		attribute of the form "a=dcsa:stream-id original-attribute", where
	"data channel subprotocol attribute", stream-id is the SCTP stream		dcsa stands for "data channel subprotocol attribute", stream-id is
	identifier assigned to this subprotocol instance, and original-		the SCTP stream identifier assigned to this subprotocol instance, and
	attribute represents the contents of the subprotocol related		original-attribute represents the contents of the subprotocol related
	attribute to be included.		attribute to be included.
	The same syntax applies to any other SDP attribute required for		The same syntax applies to any other SDP attribute required for
	negotiation of this instance of the subprotocol.		negotiation of this instance of the subprotocol.
	Formal Syntax:		Formal Syntax:
	Name: dcsa		Name: dcsa
	Value: dcsa-value		Value: dcsa-value
	skipping to change at page 11, line 11		skipping to change at page 11, line 15
	Thus in the example above, the original attribute line "a=accept-		Thus in the example above, the original attribute line "a=accept-
	types:text/plain" is represented by the attribute line "a=dcsa:2		types:text/plain" is represented by the attribute line "a=dcsa:2
	accept-types:text/plain", which specifies that this instance of the		accept-types:text/plain", which specifies that this instance of the
	MSRP subprotocol being transported on the SCTP association using the		MSRP subprotocol being transported on the SCTP association using the
	data channel with stream id 2 accepts plain text files.		data channel with stream id 2 accepts plain text files.
	As opposed to the data channel "a=dcmap:" attribute parameters, these		As opposed to the data channel "a=dcmap:" attribute parameters, these
	parameters are subject to offer/answer negotiation following the		parameters are subject to offer/answer negotiation following the
	procedures defined in the subprotocol specific documents.		procedures defined in the subprotocol specific documents.
			It is assumed that in general the usages of subprotocol related media
			level attributes are independent from the subprotocol's transport
			protocol. Such transport protocol independent subprotocol related
			attributes are used in the same way as defined in the original
			subprotocol specification, also if the subprotocol is transported
			over a data channel and if the attribute is correspondingly embedded
			in a "a=dcsa" attribute.
			There may be cases, where the usage of a subprotocol related media
			level attribute depends on the subprotocol's transport protocol. In
			such cases the subprotocol related usage of the attribute is expected
			to be described for the data channel transport. A data channel
			specific usage of a subprotocol attribute is expected to be specified
			in the same document, which registers the subprotocol's identifier
			for data channel usage as described in Section 8.1.
	5.1.2.2. dcsa Multiplexing Category		5.1.2.2. dcsa Multiplexing Category
	The multiplexing category of the "a=dcsa:" attribute is SPECIAL.		The multiplexing category of the "a=dcsa:" attribute is SPECIAL.
	As the usage of multiple SCTP associations on top of a single DTLS		As the usage of multiple SCTP associations on top of a single DTLS
	connection is outside the scope of [I-D.ietf-mmusic-sctp-sdp], no		connection is outside the scope of [I-D.ietf-mmusic-sctp-sdp], no
	"a=dcsa:" attribute multiplexing rules are specified for the		"a=dcsa:" attribute multiplexing rules are specified for the
	UDP/DTLS/SCTP and TCP/DTLS/SCTP proto values. This document does		UDP/DTLS/SCTP and TCP/DTLS/SCTP proto values. This document does
	also not specify multiplexing rules for this attribute for SCTP or		also not specify multiplexing rules for this attribute for SCTP or
	SCTP/DTLS proto values. If future extensions of		SCTP/DTLS proto values. If future extensions of
	skipping to change at page 13, line 48		skipping to change at page 14, line 12
	o Generates a new SDP offer.		o Generates a new SDP offer.
	o Determines the list of stream identifiers assigned to data		o Determines the list of stream identifiers assigned to data
	channels opened through SDP offer/answer negotiation.		channels opened through SDP offer/answer negotiation.
	o Completes the SDP offer with the "a=dcmap:" and "a=dcsa:"		o Completes the SDP offer with the "a=dcmap:" and "a=dcsa:"
	attributes needed, if any, for each SDP offer/answer negotiated		attributes needed, if any, for each SDP offer/answer negotiated
	data channel, as described in Section 5.1 and in Section 5.2.2.		data channel, as described in Section 5.1 and in Section 5.2.2.
			o If it adds "a=dcsa" attributes to the SDP offer, then it SHOULD
			add the subprotocol parameter to the "a=dcmap" attribute with a
			non-empty subprotocol identifier.
	o Sends the SDP offer.		o Sends the SDP offer.
	The peer receiving such an SDP offer performs the following:		The peer receiving such an SDP offer performs the following:
	o Parses and applies the SDP offer. Note that the typical parser		o Parses and applies the SDP offer, taking into account the
	normally ignores unknown SDP attributes, which includes data		considerations discussed in Section 5.2.5.
	channel related attributes.
	o Analyzes the channel parameters and subprotocol attributes to		o Analyzes the channel parameters and subprotocol attributes to
	determine whether to accept each offered data channel.		determine whether to accept each offered data channel.
	o For accepted data channels, it creates peer instances for the data		o For accepted data channels, it creates peer instances for the data
	channels with the agent using the channel parameters described in		channels with the agent using the channel parameters described in
	the SDP offer. Note that the agent is asked to create data		the SDP offer. Note that the agent is asked to create data
	channels with SCTP stream identifiers contained in the SDP offer		channels with SCTP stream identifiers contained in the SDP offer
	if the SDP offer is accepted.		if the SDP offer is accepted.
	skipping to change at page 17, line 12		skipping to change at page 17, line 28
	* This is allowed and indicates there are no subprotocol		* This is allowed and indicates there are no subprotocol
	parameters to convey.		parameters to convey.
	SDP answer has no "a=dcsa:" attributes for a data channel.		SDP answer has no "a=dcsa:" attributes for a data channel.
	* This is allowed and indicates there are no subprotocol		* This is allowed and indicates there are no subprotocol
	parameters to convey in the SDP answer. The number of		parameters to convey in the SDP answer. The number of
	"a=dcsa:" attributes in the SDP answer does not have to match		"a=dcsa:" attributes in the SDP answer does not have to match
	the number of "a=dcsa:" attributes in the SDP offer.		the number of "a=dcsa:" attributes in the SDP offer.
	6. Examples		SDP offer or answer has an "a=dcsa" attribute, whose subprotocol
			attribute is unknown.
			* The receiver of such an SDP offer or answer SHOULD ignore this
			entire "a=dcsa" attribute line.
			SDP offer or answer has an "a=dcsa" attribute, whose subprotocol
			attribute is known, but whose subprotocol attribute semantic is
			not known for the data channel transport case.
			* The receiver of such an SDP offer or answer SHOULD ignore this
			entire "a=dcsa" attribute line.
			6. Examples
	SDP offer:		SDP offer:
	m=application 10001 UDP/DTLS/SCTP webrtc-datachannel		m=application 10001 UDP/DTLS/SCTP webrtc-datachannel
	c=IN IP4 10.10.10.1		c=IN IP4 10.10.10.1
	a=max-message-size:100000		a=max-message-size:100000
	a=sctp-port:5000		a=sctp-port:5000
	a=setup:actpass		a=setup:actpass
	a=connection:new		a=connection:new
	a=fingerprint:SHA-1 \		a=fingerprint:SHA-1 \
	4A:AD:B9:B1:3F:82:18:3B:54:02:12:DF:3E:5D:49:6B:19:E5:7C:AB		4A:AD:B9:B1:3F:82:18:3B:54:02:12:DF:3E:5D:49:6B:19:E5:7C:AB
	a=dcmap:0 subprotocol="BFCP";label="BFCP"		a=dcmap:0 subprotocol="BFCP";label="BFCP"
	skipping to change at page 20, line 13		skipping to change at page 21, line 13
	The following text should be added following the title of the table.		The following text should be added following the title of the table.
	"This table also includes subprotocol identifiers specified for usage		"This table also includes subprotocol identifiers specified for usage
	within a WebRTC data channel."		within a WebRTC data channel."
	The following reference should be added to under the heading		The following reference should be added to under the heading
	reference: "RFC XXXX".		reference: "RFC XXXX".
	This document assigns no new values to this table.		This document assigns no new values to this table.
			A subprotocol may simultaneously be defined for data channel
			transport and for Websocket transport. In such a case the
			"Subprotocol Definition" and "Reference" cells in the subprotocol's
			row of the IANA "WebSocket Subprotocol Name Registry" table should
			contain two entries. One entry in each of these cells should refer
			to the Websocket related subprotocol specification, and the other
			entry should refer to the data channel related subprotocol
			specification.
	NOTE to RFC Editor: Please replace "XXXX" with the number of this		NOTE to RFC Editor: Please replace "XXXX" with the number of this
	RFC.		RFC.
	8.2. New SDP Attributes		8.2. New SDP Attributes
	8.2.1. dcmap		8.2.1. dcmap
	NOTE to RFC Editor: Please replace "XXXX" with the number of this		NOTE to RFC Editor: Please replace "XXXX" with the number of this
	RFC.		RFC.
	skipping to change at page 21, line 28		skipping to change at page 22, line 31
	9. Acknowledgments		9. Acknowledgments
	The authors wish to acknowledge the borrowing of ideas from other		The authors wish to acknowledge the borrowing of ideas from other
	internet drafts by Salvatore Loreto, Gonzalo Camarillo, Peter Dunkley		internet drafts by Salvatore Loreto, Gonzalo Camarillo, Peter Dunkley
	and Gavin Llewellyn, and to thank Roni Even, Christian Groves, Gunnar		and Gavin Llewellyn, and to thank Roni Even, Christian Groves, Gunnar
	Hellstrom, Christer Holmberg, Paul Kyzivat, Jonathan Lennox, and Uwe		Hellstrom, Christer Holmberg, Paul Kyzivat, Jonathan Lennox, and Uwe
	Rauschenbach for their invaluable comments.		Rauschenbach for their invaluable comments.
	10. CHANGE LOG		10. CHANGE LOG
	10.1. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-06'		10.1. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-07'
	o Changes addressing Christian Grove's WGLC review comments raised		o Addition of two new paragraphs to Section 5.1.2.1 regarding
			subprotocol attribute relationship with transport protocol.
			o Addition of a note to Section 8.1 regarding subprotocols
			simultaneously defined for data channel and Websocket usage.
			o Addition of two further SDP offer/answer considerations to
			Section 5.2.5 regarding unknown subprotocol attributes and known
			subprotocol attributes with unknown data channel transport related
			semantic.
			10.2. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-06'
			o Changes addressing Christian Groves's WGLC review comments raised
	in http://www.ietf.org/mail-archive/web/mmusic/current/		in http://www.ietf.org/mail-archive/web/mmusic/current/
	msg15357.html and http://www.ietf.org/mail-		msg15357.html and http://www.ietf.org/mail-
	archive/web/mmusic/current/msg15359.html.		archive/web/mmusic/current/msg15359.html.
	10.2. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-05'		10.3. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-05'
	o In IANA registration Section 8.2.1 and Section 8.2.2 replacement		o In IANA registration Section 8.2.1 and Section 8.2.2 replacement
	of contact name and e-mail address with "MMUSIC Chairs" and		of contact name and e-mail address with "MMUSIC Chairs" and
	"mmusic-chairs@ietf.org".		"mmusic-chairs@ietf.org".
	o In Section 5.1.2.1 replacement of "Thus in the example above, the		o In Section 5.1.2.1 replacement of "Thus in the example above, the
	original attribute line "a=accept- types:text/plain" is		original attribute line "a=accept- types:text/plain" is
	represented by the attribute line "a=dcsa:2 accept-types:text/		represented by the attribute line "a=dcsa:2 accept-types:text/
	plain", which specifies that this instance of MSRP being		plain", which specifies that this instance of MSRP being
	transported on the SCTP association using the data channel with		transported on the SCTP association using the data channel with
	skipping to change at page 22, line 23		skipping to change at page 23, line 42
	o Move of the last but one paragraph of Section 5.1.2.1 starting		o Move of the last but one paragraph of Section 5.1.2.1 starting
	with "The same syntax applies to ..." right in front of the formal		with "The same syntax applies to ..." right in front of the formal
	syntax definition of the "dcsa" attribute.		syntax definition of the "dcsa" attribute.
	o Modifications of the text in Section 5.1.1.2 and Section 5.1.2.2		o Modifications of the text in Section 5.1.1.2 and Section 5.1.2.2
	in order not to explicitly restrict usage of the "a=dcmap:" and		in order not to explicitly restrict usage of the "a=dcmap:" and
	"a=dcsa:" attributes to "m" lines with proto values "UDP/DTLS/		"a=dcsa:" attributes to "m" lines with proto values "UDP/DTLS/
	SCTP" or "TCP/DTLS/SCTP".		SCTP" or "TCP/DTLS/SCTP".
	10.3. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-04'		10.4. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-04'
	o In Section 5.1.1.5 the first (and only) paragraph was "The		o In Section 5.1.1.5 the first (and only) paragraph was "The
	'subprotocol' parameter indicates which protocol the client		'subprotocol' parameter indicates which protocol the client
	expects to exchange via the channel. 'Subprotocol' is an optional		expects to exchange via the channel. 'Subprotocol' is an optional
	parameter. If the 'subprotocol' parameter is not present, then		parameter. If the 'subprotocol' parameter is not present, then
	its value defaults to the empty string." Replacement of this		its value defaults to the empty string." Replacement of this
	paragraph with following two paragraphs:		paragraph with following two paragraphs:
	* The 'subprotocol' parameter indicates which protocol the client		* The 'subprotocol' parameter indicates which protocol the client
	expects to exchange via the channel. This parameter maps to		expects to exchange via the channel. This parameter maps to
	skipping to change at page 23, line 17		skipping to change at page 24, line 34
	o Addition of new Section 5.1.1.2 describing the mux category of the		o Addition of new Section 5.1.1.2 describing the mux category of the
	dcmap SDP attribute. This section and the new "a=dcsa:" attribute		dcmap SDP attribute. This section and the new "a=dcsa:" attribute
	related mux category section are similar to the "Mux Category"		related mux category section are similar to the "Mux Category"
	sections of the "a=sctp-port:" and "a=max-message-size:"		sections of the "a=sctp-port:" and "a=max-message-size:"
	attributes in [I-D.ietf-mmusic-sctp-sdp].		attributes in [I-D.ietf-mmusic-sctp-sdp].
	o Addition of new Section 5.1.2.2 describing the mux category of the		o Addition of new Section 5.1.2.2 describing the mux category of the
	dcsa SDP attribute.		dcsa SDP attribute.
	10.4. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-03'		10.5. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-03'
	o In Section 1 replacement of "RTCWeb leaves it open for other		o In Section 1 replacement of "RTCWeb leaves it open for other
	applications to use data channels and its in-band DCEP or out-of-		applications to use data channels and its in-band DCEP or out-of-
	band non-DCEP protocols for creating them" with "... to use data		band non-DCEP protocols for creating them" with "... to use data
	channels and its in-band DCEP or other in-band or out-of-band		channels and its in-band DCEP or other in-band or out-of-band
	protocols for creating them". Additionally replacement of "In		protocols for creating them". Additionally replacement of "In
	particular, the SDP offer generated by the application includes no		particular, the SDP offer generated by the application includes no
	channel-specific information" with "... generated by the RTCweb		channel-specific information" with "... generated by the RTCweb
	data channel stack includes no channel-specific information".		data channel stack includes no channel-specific information".
	skipping to change at page 24, line 28		skipping to change at page 25, line 44
	o In Section 5.2.1 replacement of "However, an SDP offer/answer		o In Section 5.2.1 replacement of "However, an SDP offer/answer
	exchange MUST NOT be initiated if the associated SCTP stream is		exchange MUST NOT be initiated if the associated SCTP stream is
	already negotiated via DCEP" with "However, an SCTP stream MUST		already negotiated via DCEP" with "However, an SCTP stream MUST
	NOT be referenced in a dcmap or dcsa attribute of an SDP offer/		NOT be referenced in a dcmap or dcsa attribute of an SDP offer/
	answer exchange if the associated SCTP stream has already been		answer exchange if the associated SCTP stream has already been
	negotiated via DCEP".		negotiated via DCEP".
	o In the examples in Section 6 addition of the previously missing		o In the examples in Section 6 addition of the previously missing
	colons to the "a=sctp-port" attribute lines.		colons to the "a=sctp-port" attribute lines.
	10.5. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-02'		10.6. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-02'
	o Move of reference [I-D.ietf-rtcweb-jsep] from the list of		o Move of reference [I-D.ietf-rtcweb-jsep] from the list of
	normative references to the list of informative references.		normative references to the list of informative references.
	o Addition of [IANA-SDP-Parameters] to the list of informative		o Addition of [IANA-SDP-Parameters] to the list of informative
	references and addition of following two sentences to the first		references and addition of following two sentences to the first
	paragraph after the ABNF definition: "Note however that not all		paragraph after the ABNF definition: "Note however that not all
	SDP attributes are suitable as "a=dcsa:" parameter.		SDP attributes are suitable as "a=dcsa:" parameter.
	[IANA-SDP-Parameters] contains the lists of IANA registered		[IANA-SDP-Parameters] contains the lists of IANA registered
	session and media level or media level only SDP attributes."		session and media level or media level only SDP attributes."
	o In the introduction replacement of last sentence "This document		o In the introduction replacement of last sentence "This document
	defines SDP-based out-of-band negotiation procedures to establish		defines SDP-based out-of-band negotiation procedures to establish
	data channels for transport of well-defined subprotocols" with		data channels for transport of well-defined subprotocols" with
	"This document defines SDP offer/answer negotiation procedures to		"This document defines SDP offer/answer negotiation procedures to
	establish data channels for transport of well-defined		establish data channels for transport of well-defined
	subprotocols, to enable out-of-band negotiation".		subprotocols, to enable out-of-band negotiation".
	skipping to change at page 25, line 31		skipping to change at page 26, line 45
	a=dcmap".		a=dcmap".
	o Move of reference [WebRtcAPI] from list of normative references to		o Move of reference [WebRtcAPI] from list of normative references to
	list of informative references.		list of informative references.
	o Removal of almost all text parts, which discussed JavaScript or		o Removal of almost all text parts, which discussed JavaScript or
	other API specific aspects. Such API specific aspects were mainly		other API specific aspects. Such API specific aspects were mainly
	discussed in sub-sections of Section 5 and Section 5 of draft-		discussed in sub-sections of Section 5 and Section 5 of draft-
	ietf-mmusic-data-channel-sdpneg-02.		ietf-mmusic-data-channel-sdpneg-02.
	10.6. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-01'		10.7. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-01'
	o New Section 4 regarding applicability to SDP offer/answer only.		o New Section 4 regarding applicability to SDP offer/answer only.
	o Addition of new Section 8.1 "Subprotocol identifiers" as		o Addition of new Section 8.1 "Subprotocol identifiers" as
	subsection of the "IANA Considerations" related Section 8. Also		subsection of the "IANA Considerations" related Section 8. Also
	removal of the temporary note "To be completed. As [I-D.ietf-		removal of the temporary note "To be completed. As [I-D.ietf-
	rtcweb-data-protocol] this document should refer to IANA's		rtcweb-data-protocol] this document should refer to IANA's
	WebSocket Subprotocol Name Registry defined in [RFC6455]."		WebSocket Subprotocol Name Registry defined in [RFC6455]."
	o In Section 5.2.2:		o In Section 5.2.2:
	skipping to change at page 27, line 36		skipping to change at page 29, line 5
	* In the last but one paragraph replacement of "must" with "The		* In the last but one paragraph replacement of "must" with "The
	application MUST also close...".		application MUST also close...".
	o In Section 5.1.2 addition of following note after the formal		o In Section 5.1.2 addition of following note after the formal
	definition of the 'a=dcsa' attribute: "Note that the above		definition of the 'a=dcsa' attribute: "Note that the above
	reference to RFC 4566 defines were the attribute definition can be		reference to RFC 4566 defines were the attribute definition can be
	found; it does not provide any limitation on support of attributes		found; it does not provide any limitation on support of attributes
	defined in other documents in accordance with this attribute		defined in other documents in accordance with this attribute
	definition."		definition."
	10.7. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-00'		10.8. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-00'
	o In Section 3 "WebRTC data channel" was defined as "A bidirectional		o In Section 3 "WebRTC data channel" was defined as "A bidirectional
	channel consisting of paired SCTP outbound and inbound streams."		channel consisting of paired SCTP outbound and inbound streams."
	Replacement of this definition with "Data channel: A WebRTC data		Replacement of this definition with "Data channel: A WebRTC data
	channel as specified in [I-D.ietf-rtcweb-data-channel]", and		channel as specified in [I-D.ietf-rtcweb-data-channel]", and
	consistent usage of "data channel" in the remainder of the		consistent usage of "data channel" in the remainder of the
	document including the document's headline."		document including the document's headline."
	o In Section 5 removal of following note: 'OPEN ISSUE: The syntax in		o In Section 5 removal of following note: 'OPEN ISSUE: The syntax in
	[I-D.ietf-mmusic-sctp-sdp] may change as that document progresses.		[I-D.ietf-mmusic-sctp-sdp] may change as that document progresses.
	skipping to change at page 30, line 22		skipping to change at page 31, line 39
	to handle cases where a successful SDP answer is not received, in		to handle cases where a successful SDP answer is not received, in
	which case the state of the session SHOULD be kept per the last		which case the state of the session SHOULD be kept per the last
	successful SDP offer/answer."		successful SDP offer/answer."
	o Although dedicated to "a=dcmap" and "a=dcsa" SDP syntax aspects		o Although dedicated to "a=dcmap" and "a=dcsa" SDP syntax aspects
	Section 5.1.1 contained already procedural descriptions related to		Section 5.1.1 contained already procedural descriptions related to
	data channel reliability negotiation. Creation of new		data channel reliability negotiation. Creation of new
	Section 5.2.2 and moval of reliability negotiation related text to		Section 5.2.2 and moval of reliability negotiation related text to
	this new section.		this new section.
	10.8. Changes against 'draft-ejzak-mmusic-data-channel-sdpneg-02'		10.9. Changes against 'draft-ejzak-mmusic-data-channel-sdpneg-02'
	o Removal of note "[ACTION ITEM]" from section "subprotocol		o Removal of note "[ACTION ITEM]" from section "subprotocol
	parameter". As [I-D.ietf-rtcweb-data-protocol] this document		parameter". As [I-D.ietf-rtcweb-data-protocol] this document
	should refer to IANA's WebSocket Subprotocol Name Registry defined		should refer to IANA's WebSocket Subprotocol Name Registry defined
	in [RFC6455].		in [RFC6455].
	o In whole document, replacement of "unreliable" with "partially		o In whole document, replacement of "unreliable" with "partially
	reliable", which is used in [I-D.ietf-rtcweb-data-channel] and in		reliable", which is used in [I-D.ietf-rtcweb-data-channel] and in
	[I-D.ietf-rtcweb-data-protocol] in most places.		[I-D.ietf-rtcweb-data-protocol] in most places.
	skipping to change at page 31, line 24		skipping to change at page 32, line 41
	o In the "Examples" section, in the first two SDP offer examples in		o In the "Examples" section, in the first two SDP offer examples in
	the a=dcmap attribute lines 'label="BGCP"' was replaced with		the a=dcmap attribute lines 'label="BGCP"' was replaced with
	'label="BFCP"'.		'label="BFCP"'.
	o In all examples, the "m" line proto value "DTLS/SCTP" was replaced		o In all examples, the "m" line proto value "DTLS/SCTP" was replaced
	with "UDP/DTLS/SCTP" and the "a=fmtp" attribute lines were		with "UDP/DTLS/SCTP" and the "a=fmtp" attribute lines were
	replaced with "a=max-message-size" attribute lines, as per draft-		replaced with "a=max-message-size" attribute lines, as per draft-
	ietf-mmusic-sctp-sdp-12.		ietf-mmusic-sctp-sdp-12.
	10.9. Changes against '-01'		10.10. Changes against '-01'
	o Formal syntax for dcmap and dcsa attribute lines.		o Formal syntax for dcmap and dcsa attribute lines.
	o Making subprotocol as an optional parameter in dcmap.		o Making subprotocol as an optional parameter in dcmap.
	o Specifying disallowed parameter combinations for max-time and max-		o Specifying disallowed parameter combinations for max-time and max-
	retr.		retr.
	o Clarifications on WebRTC data channel close procedures.		o Clarifications on WebRTC data channel close procedures.
	10.10. Changes against '-00'		10.11. Changes against '-00'
	o Revisions to identify difference between internal and external		o Revisions to identify difference between internal and external
	negotiation and their usage.		negotiation and their usage.
	o Introduction of more generic terminology, e.g. "application"		o Introduction of more generic terminology, e.g. "application"
	instead of "browser".		instead of "browser".
	o Clarification of how "max-retr and max-time affect the usage of		o Clarification of how "max-retr and max-time affect the usage of
	unreliable and reliable WebRTC data channels.		unreliable and reliable WebRTC data channels.
	skipping to change at page 32, line 43		skipping to change at page 34, line 13
	progress), January 2015.		progress), January 2015.
	[I-D.ietf-mmusic-sctp-sdp]		[I-D.ietf-mmusic-sctp-sdp]
	Holmberg, C., Loreto, S., and G. Camarillo, "Stream		Holmberg, C., Loreto, S., and G. Camarillo, "Stream
	Control Transmission Protocol (SCTP)-Based Media Transport		Control Transmission Protocol (SCTP)-Based Media Transport
	in the Session Description Protocol (SDP)", draft-ietf-		in the Session Description Protocol (SDP)", draft-ietf-
	mmusic-sctp-sdp-15 (work in progress), September 2015.		mmusic-sctp-sdp-15 (work in progress), September 2015.
	[I-D.ietf-mmusic-sdp-mux-attributes]		[I-D.ietf-mmusic-sdp-mux-attributes]
	Nandakumar, S., "A Framework for SDP Attributes when		Nandakumar, S., "A Framework for SDP Attributes when
	Multiplexing", draft-ietf-mmusic-sdp-mux-attributes-10		Multiplexing", draft-ietf-mmusic-sdp-mux-attributes-12
	(work in progress), July 2015.		(work in progress), January 2016.
	11.2. Informative References		11.2. Informative References
	[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.
	[RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol",		[RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol",
	RFC 4960, DOI 10.17487/RFC4960, September 2007,		RFC 4960, DOI 10.17487/RFC4960, September 2007,
	skipping to change at page 36, line 18		skipping to change at page 37, line 32
	negotiated without DCEP, the data channel stack always performs an		negotiated without DCEP, the data channel stack always performs an
	SCTP SSN reset for this channel.		SCTP SSN reset for this channel.
	Depending upon the method used for DCEP-less negotiation and the		Depending upon the method used for DCEP-less negotiation and the
	subprotocol associated with the data channel, the closing might in		subprotocol associated with the data channel, the closing might in
	addition be signaled to the peer via SDP offer/answer negotiation.		addition be signaled to the peer via SDP offer/answer negotiation.
	Authors' Addresses		Authors' Addresses
	Keith Drage (editor)		Keith Drage (editor)
	Alcatel-Lucent		Nokia
	Quadrant, Stonehill Green, Westlea		Quadrant, Stonehill Green, Westlea
	Swindon		Swindon
	UK		UK
	Email: keith.drage@alcatel-lucent.com		Email: Keith.Drage@nokia.com
	Maridi R. Makaraju (Raju)		Maridi R. Makaraju (Raju)
	Alcatel-Lucent		Nokia
	2000 Lucent Lane		2000 Lucent Lane
	Naperville, Illinois		Naperville, Illinois
	US		US
	Email: Raju.Makaraju@alcatel-lucent.com		Email: Raju.Makaraju@nokia.com
	Juergen Stoetzer-Bradler		Juergen Stoetzer-Bradler
	Alcatel-Lucent		Nokia
	Lorenzstrasse 10		Lorenzstrasse 10
	D-70435 Stuttgart		D-70435 Stuttgart
	Germany		Germany
	Email: Juergen.Stoetzer-Bradler@alcatel-lucent.com		Email: Juergen.Stoetzer-Bradler@nokia.com
	Richard Ejzak		Richard Ejzak
	Unaffiliated		Unaffiliated
	Email: richard.ejzak@gmail.com		Email: richard.ejzak@gmail.com
	Jerome Marcon		Jerome Marcon
	Unaffiliated		Unaffiliated
End of changes. 42 change blocks.
	66 lines changed or deleted		121 lines changed or added
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