draft-ietf-mmusic-data-channel-sdpneg-16.txt   draft-ietf-mmusic-data-channel-sdpneg-17.txt 
MMUSIC K. Drage MMUSIC K. Drage
Internet-Draft Unaffiliated Internet-Draft Unaffiliated
Intended status: Standards Track M. Makaraju Intended status: Standards Track M. Makaraju
Expires: June 28, 2018 Nokia Expires: October 6, 2018 Nokia
J. Stoetzer-Bradler J. Stoetzer-Bradler
R. Ejzak R. Ejzak
J. Marcon J. Marcon
Unaffiliated Unaffiliated
R. Even, Ed. R. Even, Ed.
Huawei Huawei
December 25, 2017 April 4, 2018
SDP-based Data Channel Negotiation SDP-based Data Channel Negotiation
draft-ietf-mmusic-data-channel-sdpneg-16 draft-ietf-mmusic-data-channel-sdpneg-17
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 7 skipping to change at page 2, line 7
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 June 28, 2018. This Internet-Draft will expire on October 6, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Applicability Statement . . . . . . . . . . . . . . . . . . . 6 4. Applicability Statement . . . . . . . . . . . . . . . . . . . 6
5. SDP Data Channel attributes . . . . . . . . . . . . . . . . . 6 5. SDP Data Channel Attributes . . . . . . . . . . . . . . . . . 6
5.1. SDP data channel attributes . . . . . . . . . . . . . . . 6 5.1. SDP DCMAP Attribute . . . . . . . . . . . . . . . . . . . 6
5.1.1. SDP Attribute for Data Channel Parameter Negotiation 6 5.1.1. DCMAP Attribute Syntax . . . . . . . . . . . . . . . 7
5.1.2. Other Media Level Attributes . . . . . . . . . . . . 10 5.1.2. Dcmap-stream-id Parameter . . . . . . . . . . . . . . 8
5.1.3. Label Parameter . . . . . . . . . . . . . . . . . . . 8
5.1.4. Subprotocol Parameter . . . . . . . . . . . . . . . . 8
5.1.5. Max-retr Parameter . . . . . . . . . . . . . . . . . 9
5.1.6. Max-time Parameter . . . . . . . . . . . . . . . . . 9
5.1.7. Ordered Parameter . . . . . . . . . . . . . . . . . . 9
5.1.8. Priority Parameter . . . . . . . . . . . . . . . . . 10
5.1.9. DCMAP Multiplexing Category . . . . . . . . . . . . . 10
5.2. SDP DCSA Attribute . . . . . . . . . . . . . . . . . . . 10
5.2.1. DCSA Syntax . . . . . . . . . . . . . . . . . . . . . 11
5.2.2. DCSA Multiplexing Category . . . . . . . . . . . . . 12
6. SDP Offer/Answer Procedures . . . . . . . . . . . . . . . . . 12 6. SDP Offer/Answer Procedures . . . . . . . . . . . . . . . . . 12
6.1. Managing Stream Identifiers . . . . . . . . . . . . . . . 12 6.1. Managing Stream Identifiers . . . . . . . . . . . . . . . 12
6.2. Negotiating Data Channel Parameters . . . . . . . . . . . 13 6.2. Negotiating Data Channel Parameters . . . . . . . . . . . 13
6.3. Generating initial Offer . . . . . . . . . . . . . . . . 14 6.3. Generating Initial Offer . . . . . . . . . . . . . . . . 14
6.4. Generating SDP answer . . . . . . . . . . . . . . . . . . 15 6.4. Generating SDP Answer . . . . . . . . . . . . . . . . . . 14
6.5. Offerer Processing of the SDP Answer . . . . . . . . . . 15 6.5. Offerer Processing of the SDP Answer . . . . . . . . . . 15
6.6. Closing a Data Channel . . . . . . . . . . . . . . . . . 16 6.6. Subsequent Offers . . . . . . . . . . . . . . . . . . . . 16
6.6.1. Closing a Data Channel . . . . . . . . . . . . . . . 16
6.7. Various SDP Offer/Answer Scenarios and Considerations . . 17 6.7. Various SDP Offer/Answer Scenarios and Considerations . . 17
7. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 18 7. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 18
8. Security Considerations . . . . . . . . . . . . . . . . . . . 21 8. Security Considerations . . . . . . . . . . . . . . . . . . . 21
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
9.1. Subprotocol Identifiers . . . . . . . . . . . . . . . . . 22 9.1. Subprotocol Identifiers . . . . . . . . . . . . . . . . . 22
9.2. New SDP Attributes . . . . . . . . . . . . . . . . . . . 22 9.2. New SDP Attributes . . . . . . . . . . . . . . . . . . . 22
9.2.1. dcmap . . . . . . . . . . . . . . . . . . . . . . . . 22 9.2.1. dcmap . . . . . . . . . . . . . . . . . . . . . . . . 22
9.2.2. dcsa . . . . . . . . . . . . . . . . . . . . . . . . 23 9.2.2. dcsa . . . . . . . . . . . . . . . . . . . . . . . . 23
9.3. New Usage Level . . . . . . . . . . . . . . . . . . . . . 23 9.3. New Usage Level . . . . . . . . . . . . . . . . . . . . . 23
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 24 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 24
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Data channel subprotocol: The application protocol which is Data channel subprotocol: The application protocol which is
transported over a single data channel. Data channel subprotocol transported over a single data channel. Data channel subprotocol
messages are sent as data channel payload over an established data messages are sent as data channel payload over an established data
channel. If an SDP offer/answer exchange is used as specified in channel. If an SDP offer/answer exchange is used as specified in
this document to negotiate the establishment of data channels, this document to negotiate the establishment of data channels,
corresponding data channel properties, associated data channel corresponding data channel properties, associated data channel
subprotocols and data channel subprotocol properties, then the subprotocols and data channel subprotocol properties, then the
data channel subprotocols may be identified by the values of the data channel subprotocols may be identified by the values of the
"subprotocol" parameters of the SDP "a=dcmap" attribute as "subprotocol" parameters of the SDP "a=dcmap" attribute as
described in Section 5.1.1.5. Within this document the term "data described in Section 5.1.4. Within this document the term "data
channel subprotocol" is often abbreviated as just "subprotocol". channel subprotocol" is often abbreviated as just "subprotocol".
DCEP: Data Channel Establishment Protocol defined in DCEP: Data Channel Establishment Protocol defined in
[I-D.ietf-rtcweb-data-protocol]. [I-D.ietf-rtcweb-data-protocol].
In-band: Transmission through the peer-to-peer SCTP association. In-band: Transmission through the peer-to-peer SCTP association.
Out-of-band: Transmission through the application signaling path. Out-of-band: Transmission through the application signaling path.
Peer: From the perspective of one of the agents in a session, its Peer: From the perspective of one of the agents in a session, its
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Stream identifier: The identifier of the outbound and inbound SCTP Stream identifier: The identifier of the outbound and inbound SCTP
streams composing a data channel. streams composing a data channel.
4. Applicability Statement 4. Applicability Statement
The mechanism in this document only applies to the Session The mechanism in this document only applies to the Session
Description Protocol (SDP) [RFC4566], when used together with the SDP Description Protocol (SDP) [RFC4566], when used together with the SDP
offer/answer mechanism [RFC3264]. Declarative usage of SDP is out of offer/answer mechanism [RFC3264]. Declarative usage of SDP is out of
scope of this document, and is thus undefined. scope of this document, and is thus undefined.
5. SDP Data Channel attributes 5. SDP Data Channel Attributes
This section defines an SDP extension by which two clients can
negotiate data channel-specific and subprotocol-specific parameters
without using DCEP [I-D.ietf-rtcweb-data-protocol]. This SDP
extension only defines usage in the context of SDP offer/answer.
Appendix A provides information how data channels work in general and This sections defines new SDP media-level attributes, that can be
especially summarizes some key aspects, which should be considered used together with the SDP Offer/Answer mechanism to negotiate data
for the negotiation of data channels if DCEP is not used. channel-specific and subprotocol-specific parameters, without the
usage of DCEP [I-D.ietf-rtcweb-data-protocol].
5.1. SDP data channel attributes Note: Appendix A provides information how data channels work in
general and especially summarizes some key aspects, which should be
considered for the negotiation of data channels if DCEP is not used.
Two new SDP attributes are defined to support SDP offer/answer Two new SDP attributes are defined to support SDP offer/answer
negotiation of data channels. The first attribute provides for negotiation of data channels. The first attribute provides for
negotiation of channel-specific parameters. The second attribute negotiation of channel-specific parameters. The second attribute
provides for negotiation of subprotocol-specific parameters. provides for negotiation of subprotocol-specific parameters.
5.1.1. SDP Attribute for Data Channel Parameter Negotiation 5.1. SDP DCMAP Attribute
This section defines a new media level attribute "a=dcmap:" that This section defines a new media level attribute "a=dcmap:" that
defines the data channel parameters for each data channel to be defines the data channel parameters for each data channel to be
negotiated. The attribute specifies the following parameters for a negotiated.
data channel: SCTP stream identifier, subprotocol, label, maximal
number of retransmissions, maximal retransmission time, order of
delivery, and priority.
The intention in exchanging this attribute is to create, on two The intention in exchanging this attribute is to create, on two
peers, without use of DCEP [I-D.ietf-rtcweb-data-protocol], matched peers, without use of DCEP [I-D.ietf-rtcweb-data-protocol], matched
data channels as pairs of oppositely directed SCTP streams having the data channels as pairs of oppositely directed SCTP streams having the
same set of attributes. It is assumed that the data channel same set of attributes. It is assumed that the data channel
properties (reliable/partially reliable, ordered/unordered) are properties (reliable/partially reliable, ordered/unordered) are
suitable per the subprotocol transport requirements. suitable per the subprotocol transport requirements.
5.1.1.1. dcmap Attribute 5.1.1. DCMAP Attribute Syntax
"a=dcmap:" is a media level attribute having following ABNF "a=dcmap:" is a media level attribute having the following ABNF
(Augmented Backus-Naur Form, [RFC5234]) syntax. (Augmented Backus-Naur Form, [RFC5234]) syntax.
Formal Syntax: Formal Syntax:
Name: dcmap Name: dcmap
Value: dcmap-value Value: dcmap-value
Usage Level: media Usage Level: media
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a=dcmap:4 label="foo%09bar";ordered=true;max-time=15000 a=dcmap:4 label="foo%09bar";ordered=true;max-time=15000
Note: The last example (a=dcmap:4) shows a 'label' parameter value Note: The last example (a=dcmap:4) shows a 'label' parameter value
which contains one non-printable 'escaped-char' character (the which contains one non-printable 'escaped-char' character (the
tabulator character). tabulator character).
Within an 'a=dcmap:' attribute line's 'dcmap-opt' value either only Within an 'a=dcmap:' attribute line's 'dcmap-opt' value either only
one 'maxretr-opt' parameter or one 'maxtime-opt' parameter MAY be one 'maxretr-opt' parameter or one 'maxtime-opt' parameter MAY be
present. Both MUST NOT be present. present. Both MUST NOT be present.
5.1.1.2. dcmap Multiplexing Category 5.1.2. Dcmap-stream-id Parameter
Multiplexing characteristics of SDP attributes are described in
[I-D.ietf-mmusic-sdp-mux-attributes].
The multiplexing category of the "a=dcmap:" attribute is SPECIAL.
As the usage of multiple SCTP associations on top of a single DTLS
association is outside the scope of [I-D.ietf-mmusic-sctp-sdp], no
"a=dcmap:" attribute multiplexing rules are specified for the
UDP/DTLS/SCTP and TCP/DTLS/SCTP proto values. If future extensions
of [I-D.ietf-mmusic-sctp-sdp] define how to negotiate multiplexing of
multiple SCTP associations on top of a single DTLS association, or
how to add multiple SCTP associations to one BUNDLE group, then
multiplexing rules for the "a=dcmap:" attribute need to be defined as
well, for instance in an extension of this SDP offer/answer based
data channel negotiation specification.
5.1.1.3. dcmap-stream-id Parameter
The 'dcmap-stream-id' parameter indicates the SCTP stream identifier The 'dcmap-stream-id' parameter indicates the SCTP stream identifier
within the SCTP association used to form the data channel. within the SCTP association used to form the data channel.
5.1.1.4. label Parameter 5.1.3. Label Parameter
The 'label' parameter indicates the name of the channel. It The 'label' parameter indicates the name of the channel. It
represents a label that can be used to distinguish, in the context of represents a label that can be used to distinguish, in the context of
the WebRTC API [WebRtcAPI], an RTCDataChannel object from other the WebRTC API [WebRtcAPI], an RTCDataChannel object from other
RTCDataChannel objects. This parameter maps to the 'Label' parameter RTCDataChannel objects. This parameter maps to the 'Label' parameter
defined in [I-D.ietf-rtcweb-data-protocol]. The 'label' parameter is defined in [I-D.ietf-rtcweb-data-protocol]. The 'label' parameter is
optional. If it is not present, then its value defaults to the empty optional. If it is not present, then its value defaults to the empty
string. string.
Note: The empty string MAY also be explicitly used as a 'label' Note: The empty string MAY also be explicitly used as a 'label'
value, such that 'label=""' is equivalent to the 'label' parameter value, such that 'label=""' is equivalent to the 'label' parameter
not being present at all. [I-D.ietf-rtcweb-data-protocol] allows the not being present at all. [I-D.ietf-rtcweb-data-protocol] allows the
DATA_CHANNEL_OPEN message's 'Label' value to be an empty string. DATA_CHANNEL_OPEN message's 'Label' value to be an empty string.
5.1.1.5. subprotocol Parameter 5.1.4. Subprotocol Parameter
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 the expects to exchange via the channel. This parameter maps to the
'Protocol' parameter defined in [I-D.ietf-rtcweb-data-protocol]. 'Protocol' parameter defined in [I-D.ietf-rtcweb-data-protocol].
Section 9.1 specifies how new subprotocol parameter values are Section 9.1 specifies how new subprotocol parameter values are
registered. 'Subprotocol' is an optional parameter. If the registered. 'Subprotocol' is an optional parameter. If the
'subprotocol' parameter is not present, then its value defaults to an 'subprotocol' parameter is not present, then its value defaults to an
empty string. empty string.
Note: The empty string MAY also be explicitly used as 'subprotocol' Note: The empty string MAY also be explicitly used as 'subprotocol'
value, such that 'subprotocol=""' is equivalent to the 'subprotocol' value, such that 'subprotocol=""' is equivalent to the 'subprotocol'
parameter not being present at all. [I-D.ietf-rtcweb-data-protocol] parameter not being present at all. [I-D.ietf-rtcweb-data-protocol]
allows the DATA_CHANNEL_OPEN message's 'Subprotocol' value to be an allows the DATA_CHANNEL_OPEN message's 'Subprotocol' value to be an
empty string. empty string.
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registered. 'Subprotocol' is an optional parameter. If the registered. 'Subprotocol' is an optional parameter. If the
'subprotocol' parameter is not present, then its value defaults to an 'subprotocol' parameter is not present, then its value defaults to an
empty string. empty string.
Note: The empty string MAY also be explicitly used as 'subprotocol' Note: The empty string MAY also be explicitly used as 'subprotocol'
value, such that 'subprotocol=""' is equivalent to the 'subprotocol' value, such that 'subprotocol=""' is equivalent to the 'subprotocol'
parameter not being present at all. [I-D.ietf-rtcweb-data-protocol] parameter not being present at all. [I-D.ietf-rtcweb-data-protocol]
allows the DATA_CHANNEL_OPEN message's 'Subprotocol' value to be an allows the DATA_CHANNEL_OPEN message's 'Subprotocol' value to be an
empty string. empty string.
5.1.1.6. max-retr Parameter 5.1.5. Max-retr Parameter
This parameter indicates that the data channel is partially reliable. This parameter indicates that the data channel is partially reliable.
The 'max-retr' parameter indicates the maximal number of times a user The 'max-retr' parameter indicates the maximal number of times a user
message will be retransmitted. The max-retr parameter is optional. message will be retransmitted. The max-retr parameter is optional.
If the max-retr parameter is not present, then the maximal number of If the max-retr parameter is not present, then the maximal number of
retransmissions is determined as per the generic SCTP retransmission retransmissions is determined as per the generic SCTP retransmission
rules as specified in [RFC4960]. This parameter maps to the 'Number rules as specified in [RFC4960]. This parameter maps to the 'Number
of RTX' parameter defined in [I-D.ietf-rtcweb-data-protocol]. of RTX' parameter defined in [I-D.ietf-rtcweb-data-protocol].
5.1.1.7. max-time Parameter 5.1.6. Max-time Parameter
This parameter indicates that the data channel is partially reliable. This parameter indicates that the data channel is partially reliable.
A user message will no longer be transmitted or retransmitted after a A user message will no longer be transmitted or retransmitted after a
specified life-time given in milliseconds in the 'max-time' specified life-time given in milliseconds in the 'max-time'
parameter. The max-time parameter is optional. If the max-time parameter. The max-time parameter is optional. If the max-time
parameter is not present, then the generic SCTP retransmission timing parameter is not present, then the generic SCTP retransmission timing
rules apply as specified in [RFC4960]. This parameter maps to the rules apply as specified in [RFC4960]. This parameter maps to the
'Lifetime in ms' parameter defined in 'Lifetime in ms' parameter defined in
[I-D.ietf-rtcweb-data-protocol]. [I-D.ietf-rtcweb-data-protocol].
5.1.1.8. ordered Parameter 5.1.7. Ordered Parameter
The 'ordered' parameter with value "true" indicates that the receiver The 'ordered' parameter with value "true" indicates that the receiver
MUST dispatch DATA chunks in the data channel to the upper layer MUST dispatch DATA chunks in the data channel to the upper layer
while preserving the order. The ordered parameter is optional and while preserving the order. The ordered parameter is optional and
takes two values: "true" for ordered and "false" for unordered takes two values: "true" for ordered and "false" for unordered
delivery with "true" as the default value. Any other value is delivery with "true" as the default value. Any other value is
ignored and default "ordered=true" is assumed. In the absence of ignored and default "ordered=true" is assumed. In the absence of
this parameter "ordered=true" is assumed. This parameter maps to the this parameter "ordered=true" is assumed. This parameter maps to the
ordered or unordered data channel types as defined in ordered or unordered data channel types as defined in
[I-D.ietf-rtcweb-data-protocol]. [I-D.ietf-rtcweb-data-protocol].
5.1.1.9. priority Parameter 5.1.8. Priority Parameter
The 'priority' parameter indicates the data channel's priority The 'priority' parameter indicates the data channel's priority
relative to the priorities of other data channels, which may relative to the priorities of other data channels, which may
additionally exist over the same SCTP association. The 'priority' additionally exist over the same SCTP association. The 'priority'
parameter maps to the 'Priority' parameter defined in parameter maps to the 'Priority' parameter defined in
[I-D.ietf-rtcweb-data-protocol]. The 'priority' parameter is [I-D.ietf-rtcweb-data-protocol]. The 'priority' parameter is
optional. In the absence of this parameter "priority=256" is optional. In the absence of this parameter "priority=256" is
assumed. assumed.
5.1.2. Other Media Level Attributes 5.1.9. DCMAP Multiplexing Category
Multiplexing characteristics of SDP attributes are described in
[I-D.ietf-mmusic-sdp-mux-attributes].
The multiplexing category of the "a=dcmap:" attribute is SPECIAL.
As the usage of multiple SCTP associations on top of a single DTLS
association is outside the scope of [I-D.ietf-mmusic-sctp-sdp], no
"a=dcmap:" attribute multiplexing rules are specified for the
UDP/DTLS/SCTP and TCP/DTLS/SCTP proto values. If future extensions
of [I-D.ietf-mmusic-sctp-sdp] define how to negotiate multiplexing of
multiple SCTP associations on top of a single DTLS association, or
how to add multiple SCTP associations to one BUNDLE group, then
multiplexing rules for the "a=dcmap:" attribute need to be defined as
well, for instance in an extension of this SDP offer/answer based
data channel negotiation specification.
5.2. SDP DCSA Attribute
In the SDP media description, each data channel declaration MAY also In the SDP media description, each data channel declaration MAY also
be followed by other media level SDP attributes, which are either be followed by other media level SDP attributes, which are either
specifically defined for or applied to the subprotocol in use. Each specifically defined for or applied to the subprotocol in use. Each
of these attributes is represented by one new attribute line, and it of these attributes is represented by one new attribute line, and it
includes the contents of a media-level SDP attribute already defined includes the contents of a media-level SDP attribute already defined
for use with this (sub)protocol in another IETF (Internet Engineering for use with this (sub)protocol in another IETF (Internet Engineering
Task Force) document. Subprotocol specific attributes MAY also be Task Force) document. Subprotocol specific attributes MAY also be
defined for exclusive use with data channel transport, but MUST use defined for exclusive use with data channel transport, but MUST use
the same syntax described here for other subprotocol related the same syntax described here for other subprotocol related
attributes. attributes.
5.1.2.1. dcsa Attribute
Each SDP attribute, related to the subprotocol, that would normally Each SDP attribute, related to the subprotocol, that would normally
be used to negotiate the subprotocol using SDP offer/answer is be used to negotiate the subprotocol using SDP offer/answer is
replaced with an attribute of the form "a=dcsa:stream-id original- replaced with an attribute of the form "a=dcsa:stream-id original-
attribute", where dcsa stands for "data channel subprotocol attribute", where dcsa stands for "data channel subprotocol
attribute", stream-id is the SCTP stream identifier assigned to this attribute", stream-id is the SCTP stream identifier assigned to this
subprotocol instance, and original-attribute represents the contents subprotocol instance, and original-attribute represents the contents
of the subprotocol related attribute to be included. of the subprotocol related 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.
5.2.1. DCSA Syntax
Formal Syntax: Formal Syntax:
Name: dcsa Name: dcsa
Value: dcsa-value Value: dcsa-value
Usage Level: media Usage Level: media
Charset Dependent: no Charset Dependent: no
Syntax: Syntax:
dcsa-value = stream-id SP attribute dcsa-value = stream-id SP attribute
attribute = <from-RFC4566> attribute = <from-RFC4566>
Example (other MSRP related SDP attributes are omitted for brevity): Example:
a=dcmap:2 subprotocol="MSRP";ordered=true;label="MSRP"
a=dcsa:2 accept-types:text/plain a=dcsa:2 accept-types:text/plain
Note that the above reference to [RFC4566] defines where the Note that the above reference to [RFC4566] defines where the
attribute definition can be found; it does not provide any limitation attribute definition can be found; it does not provide any limitation
on support of attributes defined in other documents in accordance on support of attributes defined in other documents in accordance
with this attribute definition. Note however that not all SDP with this attribute definition. Note however that not all SDP
attributes are suitable as a "a=dcsa:" parameter. attributes are suitable as a "a=dcsa:" parameter.
[IANA-SDP-Parameters] contains the lists of IANA (Internet Assigned [IANA-SDP-Parameters] contains the lists of IANA (Internet Assigned
Numbers Authority) registered session and media level or media level Numbers Authority) registered session and media level or media level
skipping to change at page 12, line 13 skipping to change at page 12, line 17
in a "a=dcsa" attribute. in a "a=dcsa" attribute.
There may be cases, where the usage of a subprotocol related media There may be cases, where the usage of a subprotocol related media
level attribute depends on the subprotocol's transport protocol. In level attribute depends on the subprotocol's transport protocol. In
such cases the subprotocol related usage of the attribute is expected such cases the subprotocol related usage of the attribute is expected
to be described for the data channel transport. A data channel to be described for the data channel transport. A data channel
specific usage of a subprotocol attribute is expected to be specified specific usage of a subprotocol attribute is expected to be specified
in the same document that registers the subprotocol's identifier for in the same document that registers the subprotocol's identifier for
data channel usage as described in Section 9.1. data channel usage as described in Section 9.1.
5.1.2.2. dcsa Multiplexing Category 5.2.2. 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
association is outside the scope of [I-D.ietf-mmusic-sctp-sdp], no association 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. If future extensions UDP/DTLS/SCTP and TCP/DTLS/SCTP proto values. If future extensions
of [I-D.ietf-mmusic-sctp-sdp] define how to negotiate multiplexing of of [I-D.ietf-mmusic-sctp-sdp] define how to negotiate multiplexing of
multiple SCTP associations on top of a single DTLS association, or multiple SCTP associations on top of a single DTLS association, or
how to add multiple SCTP associations to one BUNDLE group, then how to add multiple SCTP associations to one BUNDLE group, then
skipping to change at page 14, line 23 skipping to change at page 14, line 23
DATA_CHANNEL_PARTIAL_RELIABLE_REXMIT_UNORDERED DATA_CHANNEL_PARTIAL_RELIABLE_REXMIT_UNORDERED
ordered=false;max-retr=<number of retransmissions> ordered=false;max-retr=<number of retransmissions>
DATA_CHANNEL_PARTIAL_RELIABLE_TIMED DATA_CHANNEL_PARTIAL_RELIABLE_TIMED
ordered=true;max-time=<lifetime in milliseconds> ordered=true;max-time=<lifetime in milliseconds>
DATA_CHANNEL_PARTIAL_RELIABLE_TIMED_UNORDERED DATA_CHANNEL_PARTIAL_RELIABLE_TIMED_UNORDERED
ordered=false;max-time=<lifetime in milliseconds> ordered=false;max-time=<lifetime in milliseconds>
6.3. Generating initial Offer 6.3. Generating Initial Offer
The procedure for opening a data channel using SDP offer/answer
negotiation starts with the agent preparing to send an SDP offer. If
a peer receives an SDP offer before starting to send a new SDP offer
with data channels that are to be SDP offer/answer negotiated, or
loses an SDP offer glare resolution procedure in this case, it MUST
wait until the ongoing SDP offer/answer completes before resuming the
SDP offer/answer negotiation procedure.
The agent that intends to send an SDP offer to create data channels The agent that intends to send an SDP offer to create data channels
through SDP offer/answer negotiation performs the following: through SDP offer/answer negotiation performs the following:
o Creates data channels using stream identifiers from the owned set o Creates data channels using stream identifiers from the owned set
(see Section 6.1). (see Section 6.1).
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 Generates 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 6.2. data channel, as described in Section 5 and in Section 6.2.
o If it adds "a=dcsa" attributes to the SDP offer, then it SHOULD o The "a=dcsa" attributes to the SDP offer SHOULD have the
add the subprotocol parameter to the "a=dcmap" attribute with a subprotocol parameters to the "a=dcmap" attribute with a non-empty
non-empty subprotocol identifier. subprotocol identifier.
o Sends the SDP offer. o Sends the SDP offer.
6.4. Generating SDP answer 6.4. Generating SDP Answer
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, taking into account the o Parses and applies the SDP offer, taking into account the
considerations discussed in Section 6.7. considerations discussed in Section 6.7.
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, the agent MUST create peer instances o For accepted data channels, the agent MUST create peer instances
for the data channels using the SCTP stream identifiers and for the data channels using the SCTP stream identifiers and
channel parameters contained in the SDP offer. channel parameters contained in the SDP offer.
o Generates an SDP answer. o Generates an SDP answer.
o Completes the SDP answer with the "a=dcmap:" and optional o Completes the SDP answer with the "a=dcmap:" and optional
"a=dcsa:" attributes needed for each SDP offer/answer negotiated "a=dcsa:" attributes needed for each SDP offer/answer negotiated
data channel, as described in Section 5.1 and in Section 6.2. data channel, as described in Section 5 and in Section 6.2.
o Sends the SDP answer. o Sends the SDP answer.
6.5. Offerer Processing of the SDP Answer 6.5. Offerer Processing of the SDP Answer
The agent receiving such an SDP answer performs the following: An offerer receiving a SDP answer performs the following:
o Closes any created data channels as described in Section 6.6 for o Closes any created data channels as described in Section 6.6.1 for
which the expected "a=dcmap:" and "a=dcsa:" attributes are not which the expected "a=dcmap:" and "a=dcsa:" attributes are not
present in the SDP answer. present in the SDP answer.
o Applies the SDP answer. o Applies the SDP answer.
Each agent application MUST wait to send data until it has Each agent application MUST wait to send data until it has
confirmation that the data channel at the peer is instantiated. For confirmation that the data channel at the peer is instantiated. For
WebRTC, this is when both data channel stacks have channel parameters WebRTC, this is when both data channel stacks have channel parameters
instantiated. This occurs: instantiated. This occurs:
skipping to change at page 16, line 11 skipping to change at page 16, line 5
o At the agent sending an SDP offer to create a new SDP offer/answer o At the agent sending an SDP offer to create a new SDP offer/answer
negotiated data channel for which there is an established SCTP negotiated data channel for which there is an established SCTP
association, when it receives the SDP answer confirming acceptance association, when it receives the SDP answer confirming acceptance
of the data channel or when it begins to receive data on the data of the data channel or when it begins to receive data on the data
channel from the peer, whichever occurs first. channel from the peer, whichever occurs first.
Note: DCEP is not used, that is neither the SDP offerer nor the SDP Note: DCEP is not used, that is neither the SDP offerer nor the SDP
answerer send an in-band DCEP DATA_CHANNEL_OPEN message. answerer send an in-band DCEP DATA_CHANNEL_OPEN message.
6.6. Closing a Data Channel 6.6. Subsequent Offers
When an application wants to add a data channel it will send a new
oofer with a new a=dcmap with a new dcmap-stream-id and optionally
a=dcsa attributes. The offer should include in the offer all
parameters of the existing channesl. If the offer wants to remove a
data channel it will remove the attributes with the dcmap-stream-id
it wants to remove, see the examples in the examples section
Section 7
6.6.1. Closing a Data Channel
When the application requests the closing of a data channel that was When the application requests the closing of a data channel that was
negotiated via SDP offer/answer, the data channel stack always negotiated via SDP offer/answer, the data channel stack always
performs an SCTP SSN reset for this channel. performs an SCTP SSN reset for this channel.
It is specific to the subprotocol whether this closing MUST in It is specific to the subprotocol whether this closing MUST in
addition be signaled to the peer via a new SDP offer/answer exchange. addition be signaled to the peer via a new SDP offer/answer exchange.
The intention to close a data channel can be signaled by sending a The intention to close a data channel can be signaled by sending a
new SDP offer which excludes the "a=dcmap:" and "a=dcsa:" attribute new SDP offer which excludes the "a=dcmap:" and "a=dcsa:" attribute
skipping to change at page 19, line 7 skipping to change at page 19, line 7
attribute is known, but whose subprotocol attribute semantic is attribute is known, but whose subprotocol attribute semantic is
not known for the data channel transport case. not known for the data channel transport case.
* The receiver of such an SDP offer or answer SHOULD ignore this * The receiver of such an SDP offer or answer SHOULD ignore this
entire "a=dcsa" attribute line. entire "a=dcsa" attribute line.
7. Examples 7. Examples
SDP offer: SDP offer:
m=application 10001 UDP/DTLS/SCTP webrtc-datachannel m=application 10001 UDP/DTLS/SCTP webrtc-datachannel
c=IN IP4 192.0.2.1 c=IN IP6 IP6 2001:db8::3
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=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=tls-id:abc3de65cddef001be82 a=tls-id:abc3de65cddef001be82
a=dcmap:0 subprotocol="BFCP";label="BFCP" a=dcmap:0 subprotocol="BFCP";label="BFCP"
SDP answer: SDP answer:
m=application 10002 UDP/DTLS/SCTP webrtc-datachannel m=application 10002 UDP/DTLS/SCTP webrtc-datachannel
c=IN IP4 192.0.2.2 c=IN IP6 IP6 2001:db8::1
a=max-message-size:100000 a=max-message-size:100000
a=sctp-port:5002 a=sctp-port:5002
a=setup:passive a=setup:passive
a=fingerprint:SHA-1 \ a=fingerprint:SHA-1 \
5B:AD:67:B1:3E:82:AC:3B:90:02:B1:DF:12:5D:CA:6B:3F:E5:54:FA 5B:AD:67:B1:3E:82:AC:3B:90:02:B1:DF:12:5D:CA:6B:3F:E5:54:FA
a=tls-id:dcb3ae65cddef0532d42 a=tls-id:dcb3ae65cddef0532d42
Figure 1: Example 1 Figure 1: Example 1
In the above example the SDP answerer rejected the data channel with In the above example the SDP answerer rejected the data channel with
skipping to change at page 23, line 6 skipping to change at page 23, line 6
9.2.1. dcmap 9.2.1. 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.
This document defines a new SDP media-level attribute "a=dcmap:" as This document defines a new SDP media-level attribute "a=dcmap:" as
follows: follows:
+-----------------------+-------------------------------------------+ +-----------------------+-------------------------------------------+
| Contact name: | MMUSIC Chairs | | Contact name: | IESG Chairs |
| Contact email: | mmusic-chairs@ietf.org | | Contact email: | iesg@ietf.org |
| Attribute name: | dcmap | | Attribute name: | dcmap |
| Attribute syntax: | As per Section 5.1.1.1 | | Attribute syntax: | As per Section 5.1.1 |
| Attribute semantics: | As per Section 5.1.1.1 | | Attribute semantics: | As per Section 5.1.1 |
| Usage level: | media | | Usage level: | media |
| Charset dependent: | No | | Charset dependent: | No |
| Purpose: | Define data channel specific parameters | | Purpose: | Define data channel specific parameters |
| Appropriate values: | As per Section 5.1.1.1 | | Appropriate values: | As per Section 5.1.1 |
| O/A procedures: | As per Section 6 | | O/A procedures: | As per Section 6 |
| Mux category: | SPECIAL. See Section 5.1.1.2 | | Mux category: | SPECIAL. See Section 5.1.9 |
| Reference: | RFCXXXX | | Reference: | RFCXXXX |
+-----------------------+-------------------------------------------+ +-----------------------+-------------------------------------------+
9.2.2. dcsa 9.2.2. dcsa
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.
This document defines a new SDP media-level attribute "a=dcsa:" as This document defines a new SDP media-level attribute "a=dcsa:" as
follows: follows:
+-----------------------+-------------------------------------------+ +-----------------------+-------------------------------------------+
| Contact name: | MMUSIC Chairs | | Contact name: | IESG Chairs |
| Contact email: | mmusic-chairs@ietf.org | | Contact email: | iesg@ietf.org |
| Attribute name: | dcsa | | Attribute name: | dcsa |
| Attribute syntax: | As per Section 5.1.2.1 | | Attribute syntax: | As per Section 5.2.1 |
| Attribute semantics: | As per Section 5.1.2.1 | | Attribute semantics: | As per Section 5.2.1 |
| Usage level: | media | | Usage level: | media |
| Charset dependent: | No | | Charset dependent: | No |
| Purpose: | Define data channel subprotocol specific | | Purpose: | Define data channel subprotocol specific |
| | attributes | | | attributes |
| Appropriate values: | As per Section 5.1.2.1 | | Appropriate values: | As per Section 5.2.1 |
| O/A procedures: | As per Section 6 | | O/A procedures: | As per Section 6 |
| Mux category: | SPECIAL. See Section 5.1.2.2 | | Mux category: | SPECIAL. See Section 5.2.2 |
| Reference: | RFCXXXX | | Reference: | RFCXXXX |
+-----------------------+-------------------------------------------+ +-----------------------+-------------------------------------------+
9.3. New Usage Level 9.3. New Usage Level
This document introduces a new "Data Channel Subprotocol Attribute" This document introduces a new "Data Channel Subprotocol Attribute"
(dcsa) usage level of the SDP media description to the IANA SDP att- (dcsa) usage level of the SDP media description to the IANA SDP att-
field registry. SDP attributes that are defined for use at the dcsa field registry. SDP attributes that are defined for use at the dcsa
usage level only SHALL use the dcsa usage level when registering the usage level only SHALL use the dcsa usage level when registering the
attribute. If existing media attributes are used in a datachannel attribute. If existing media attributes are used in a datachannel
subprotocol specific way (Section 5.1.2.1), then a new dcsa usage subprotocol specific way (Section 5.2.1), then a new dcsa usage level
level MUST be defined for the existing media attribute. Where the MUST be defined for the existing media attribute. Where the SDP
SDP attribute is applicable to a particular subprotocol/s this SHALL attribute is applicable to a particular subprotocol/s this SHALL also
also be registered by indicating the applicable subprotocol be registered by indicating the applicable subprotocol identifiers
identifiers (see Section 9.1) along with the dcsa usage level. E.g. (see Section 9.1) along with the dcsa usage level. E.g.
+-----------------------+-------------------------------------------+ +-----------------------+-------------------------------------------+
| ... | ... | | ... | ... |
| Usage level: | dcsa(MSRP) | | Usage level: | dcsa(MSRP) |
| ... | ... | | ... | ... |
+-----------------------+-------------------------------------------+ +-----------------------+-------------------------------------------+
10. Acknowledgments 10. 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 Flemming Andreasen, Roni Even, and Gavin Llewellyn, and to thank Flemming Andreasen, Christian
Christian Groves, Gunnar Hellstrom, Christer Holmberg, Paul Kyzivat, Groves, Gunnar Hellstrom, Christer Holmberg, Paul Kyzivat, Jonathan
Jonathan Lennox, Uwe Rauschenbach and Roman Shpount for their Lennox, Uwe Rauschenbach and Roman Shpount for their invaluable
invaluable comments. comments.
11. CHANGE LOG 11. CHANGE LOG
11.1. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-15' 11.1. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-15'
o Editorial changes separate sections for offer/answer procedures. o Editorial changes separate sections for offer/answer procedures.
o Update security section. o Update security section.
11.2. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-14' 11.2. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-14'
skipping to change at page 25, line 35 skipping to change at page 25, line 35
rules for SCTP based media transport as specified in rules for SCTP based media transport as specified in
[I-D.ietf-mmusic-sctp-sdp] for the SDP "m" line proto values [I-D.ietf-mmusic-sctp-sdp] for the SDP "m" line proto values
UDP/DTLS/SCTP and TCP/DTLS/SCTP. In the future, data channels UDP/DTLS/SCTP and TCP/DTLS/SCTP. In the future, data channels
could be defined over other SCTP based protocols, such as SCTP could be defined over other SCTP based protocols, such as SCTP
over IP. However, corresponding potential other "m" line proto over IP. However, corresponding potential other "m" line proto
values are not considered in this document." values are not considered in this document."
o Replacement of "DTLS connection" with "DTLS association" o Replacement of "DTLS connection" with "DTLS association"
throughout the document. throughout the document.
o In sections Section 5.1.1.2 and Section 5.1.2.2 removal of the o In sections Section 5.1.9 and Section 5.2.2 removal of the
sentences "This document also does not specify multiplexing rules sentences "This document also does not specify multiplexing rules
for this attribute for SCTP or SCTP/DTLS proto values". for this attribute for SCTP or SCTP/DTLS proto values".
o In the text related to "Subsequent SDP answer" in section o In the text related to "Subsequent SDP answer" in section
Section 6.7 replacement of "The DTLS/SCTP association remains open Section 6.7 replacement of "The DTLS/SCTP association remains open
..." with "The SCTP association remains open ...". ..." with "The SCTP association remains open ...".
o In the text after the second SDP answer in section Section 7 o In the text after the second SDP answer in section Section 7
replacement of "... (after SCTP/DTLS association is setup)" with replacement of "... (after SCTP/DTLS association is setup)" with
"... (after the SCTP association is set up)". "... (after the SCTP association is set up)".
skipping to change at page 26, line 20 skipping to change at page 26, line 20
o Addition of RFC4566bis draft to list of normative references. o Addition of RFC4566bis draft to list of normative references.
o Updates of tables in Section 9.2.1 and Section 9.2.2 as per o Updates of tables in Section 9.2.1 and Section 9.2.2 as per
section 8.2.4 of RFC4566bis draft. section 8.2.4 of RFC4566bis draft.
o Addition of new Section 9.3. o Addition of new Section 9.3.
11.8. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-07' 11.8. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-07'
o Addition of two new paragraphs to Section 5.1.2.1 regarding o Addition of two new paragraphs to Section 5.2.1 regarding
subprotocol attribute relationship with transport protocol. subprotocol attribute relationship with transport protocol.
o Addition of a note to Section 9.1 regarding subprotocols o Addition of a note to Section 9.1 regarding subprotocols
simultaneously defined for data channel and Websocket usage. simultaneously defined for data channel and Websocket usage.
o Addition of two further SDP offer/answer considerations to o Addition of two further SDP offer/answer considerations to
Section 6.7 regarding unknown subprotocol attributes and known Section 6.7 regarding unknown subprotocol attributes and known
subprotocol attributes with unknown data channel transport related subprotocol attributes with unknown data channel transport related
semantic. semantic.
skipping to change at page 26, line 44 skipping to change at page 26, line 44
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.
11.10. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-05' 11.10. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-05'
o In IANA registration Section 9.2.1 and Section 9.2.2 replacement o In IANA registration Section 9.2.1 and Section 9.2.2 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 5.2.1 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
stream id 2 accepts plain text files." with "... which specifies stream id 2 accepts plain text files." with "... which specifies
that this instance of the MSRP subprotocol being transported ...". that this instance of the MSRP subprotocol being transported ...".
o The last paragraph of Section 5.1.2.1 started with "Note: This o The last paragraph of Section 5.2.1 started with "Note: This
document does not provide a complete specification ...". Removal document does not provide a complete specification ...". Removal
of "Note:" and move of this paragraph to the introduction in of "Note:" and move of this paragraph to the introduction in
Section 1 as last paragraph. Section 1 as last paragraph.
o Section 5.1.2's headline was "Subprotocol Specific Attributes". o Section 5.2's headline was "Subprotocol Specific Attributes".
Change of this headline to "Other Media Level Attributes" and Change of this headline to "Other Media Level Attributes" and
adaptations of the first paragraph of this section and the first adaptations of the first paragraph of this section and the first
paragraph of Section 5.1.2.1 in order to clarify that not only paragraph of Section 5.2.1 in order to clarify that not only those
those attributes may be encapsulated in a "dcsa" attribute, which attributes may be encapsulated in a "dcsa" attribute, which are
are specifically defined for the subprotocol, but that also other specifically defined for the subprotocol, but that also other
attributes may be encapsulated if they are related to the specific attributes may be encapsulated if they are related to the specific
subprotocol instance. subprotocol instance.
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 5.2.1 starting with
with "The same syntax applies to ..." right in front of the formal "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 5.1.9 and Section 5.2.2 in
in order not to explicitly restrict usage of the "a=dcmap:" and 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".
11.11. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-04' 11.11. 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 5.1.4 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
the 'Protocol' parameter defined in the 'Protocol' parameter defined in
[I-D.ietf-rtcweb-data-protocol]. Section 9.1 specifies how new [I-D.ietf-rtcweb-data-protocol]. Section 9.1 specifies how new
skipping to change at page 28, line 11 skipping to change at page 28, line 11
o Addition of [I-D.ietf-mmusic-sdp-mux-attributes] to list the of o Addition of [I-D.ietf-mmusic-sdp-mux-attributes] to list the of
normative references. normative references.
o Addition of dcmap attribute specific IANA registration o Addition of dcmap attribute specific IANA registration
Section 9.2.1. Section 9.2.1.
o Addition of dcsa attribute specific IANA registration o Addition of dcsa attribute specific IANA registration
Section 9.2.2. Section 9.2.2.
o Addition of new Section 5.1.1.2 describing the mux category of the o Addition of new Section 5.1.9 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 5.2.2 describing the mux category of the
dcsa SDP attribute. dcsa SDP attribute.
11.12. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-03' 11.12. 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
skipping to change at page 29, line 7 skipping to change at page 29, line 7
two clients can negotiate data channel-specific and two clients can negotiate data channel-specific and
subprotocol-specific parameters without using DCEP subprotocol-specific parameters without using DCEP
[I-D.ietf-rtcweb-data-protocol]. This SDP extension only [I-D.ietf-rtcweb-data-protocol]. This SDP extension only
defines usage in the context of SDP offer/answer." defines usage in the context of SDP offer/answer."
* Addition of new paragraph: "Appendix A provides information how * Addition of new paragraph: "Appendix A provides information how
data channels work in general and especially summarizes some data channels work in general and especially summarizes some
key aspects, which should be considered for the negotiation of key aspects, which should be considered for the negotiation of
data channels if DCEP is not used." data channels if DCEP is not used."
o In Section 5.1.1 replacement of "The intention of exchanging these o In Section 5.1 replacement of "The intention of exchanging these
attributes is to create data channels on both the peers with the attributes is to create data channels on both the peers with the
same set of attributes without actually using the DCEP same set of attributes without actually using the DCEP
[I-D.ietf-rtcweb-data-protocol]" with "The intention in exchanging [I-D.ietf-rtcweb-data-protocol]" with "The intention in exchanging
these attributes is to create, on two peers, without use of DCEP these attributes is to create, on two peers, without use of DCEP
[I-D.ietf-rtcweb-data-protocol], matched pairs of oppositely [I-D.ietf-rtcweb-data-protocol], matched pairs of oppositely
directed data channels having the same set of attributes". directed data channels having the same set of attributes".
o In Section 5.1.1.6 replacement of "The 'max-retr' parameter o In Section 5.1.5 replacement of "The 'max-retr' parameter
indicates the maximal number a user message will be retransmitted" indicates the maximal number a user message will be retransmitted"
with "The 'max-retr' parameter indicates the maximal number of with "The 'max-retr' parameter indicates the maximal number of
times a user message will be retransmitted". times a user message will be retransmitted".
o In Section 6.1 replacement of "However, an SDP offer/answer o In Section 6.1 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".
skipping to change at page 31, line 40 skipping to change at page 31, line 40
with "Initial SDP offer: No data channel is negotiated yet. The with "Initial SDP offer: No data channel is negotiated yet. The
DTLS connection and SCTP association is negotiated and, if agreed, DTLS connection and SCTP association is negotiated and, if agreed,
established as per [I-D.ietf-mmusic-sctp-sdp]." established as per [I-D.ietf-mmusic-sctp-sdp]."
o In Section 6.7 in both bullet points related to "Subsequent SDP o In Section 6.7 in both bullet points related to "Subsequent SDP
offer" and "Subsequent SDP answer" replacement of "All the offer" and "Subsequent SDP answer" replacement of "All the
externally negotiated data channels must be closed now." with "All externally negotiated data channels must be closed now." with "All
the externally negotiated data channels are expected to be closed the externally negotiated data channels are expected to be closed
now.". now.".
o In Appendix A.2.2's sixth paragraph beginning with "[ASSUMPTION]" o In Appendix A.2.2's sixth paragraph replacement of the two
replacement of the two occurrences of "must" with "MUST". occurrences of "must" with "MUST".
o In Section 5.1.1.1 in the definition of the ABNF rule "dcmap-opt" o In Section 5.1.1 in the definition of the ABNF rule "dcmap-opt"
there was a comment saying that "Either only maxretr-opt or there was a comment saying that "Either only maxretr-opt or
maxtime-opt is present. Both MUST NOT be present." Removal of maxtime-opt is present. Both MUST NOT be present." Removal of
the second normative sentence and instead addition of following the second normative sentence and instead addition of following
new paragraph to the end of this section: "Within an 'a=dcmap' new paragraph to the end of this section: "Within an 'a=dcmap'
attribute line's 'dcmap-opt' value either only one 'maxretr-opt' attribute line's 'dcmap-opt' value either only one 'maxretr-opt'
parameter or one 'maxtime-opt' parameter is present. Both MUST parameter or one 'maxtime-opt' parameter is present. Both MUST
NOT be present." NOT be present."
o In Section 5.1.1.8 replacement of the first sentence "The o In Section 5.1.7 replacement of the first sentence "The 'ordered'
'ordered' parameter with value "true" indicates that DATA chunks parameter with value "true" indicates that DATA chunks in the
in the channel MUST be dispatched to the upper layer by the channel MUST be dispatched to the upper layer by the receiver
receiver while preserving the order." with "The 'ordered' while preserving the order." with "The 'ordered' parameter with
parameter with value "true" indicates that the receiver MUST value "true" indicates that the receiver MUST dispatch DATA chunks
dispatch DATA chunks in the data channel to the upper layer while in the data channel to the upper layer while preserving the
preserving the order.". order.".
o In Section 6.3's first paragraph replacement of the one occurrence o In Section 6.3's first paragraph replacement of the one occurrence
of "must" with "..., it MUST wait until ...". of "must" with "..., it MUST wait until ...".
o In Section 6.6: o In Section 6.6.1:
* In the second paragraph replacement of "must" with "... whether * In the second paragraph replacement of "must" with "... whether
this closing MUST in addition ..." this closing MUST in addition ..."
* In the third paragraph replacement of the sentence "The port * In the third paragraph replacement of the sentence "The port
value for the "m" line SHOULD NOT be changed (e.g., to zero) value for the "m" line SHOULD NOT be changed (e.g., to zero)
when closing a data channel ..." with "The offerer SHOULD NOT when closing a data channel ..." with "The offerer SHOULD NOT
change the port value for the "m" line (e.g., to zero) when change the port value for the "m" line (e.g., to zero) when
closing a data channel ...". closing a data channel ...".
* In the last but two paragraph replacement of the sentence "... * In the last but two paragraph replacement of the sentence "...
then an SDP offer which excludes this closed data channel then an SDP offer which excludes this closed data channel
SHOULD be generated." with "... then the client SHOULD generate SHOULD be generated." with "... then the client SHOULD generate
an SDP offer which excludes this closed data channel.". an SDP offer which excludes this closed data channel.".
* 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 5.2 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."
11.15. Changes against 'draft-ietf-mmusic-data-channel-sdpneg-00' 11.15. 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."
skipping to change at page 33, line 10 skipping to change at page 33, line 10
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.
In particular we expect "webrtc-datachannel" to become a more In particular we expect "webrtc-datachannel" to become a more
general term.' general term.'
o Consistent usage of '"m" line' in whole document as per [RFC4566]. o Consistent usage of '"m" line' in whole document as per [RFC4566].
o In Section 5.1.1 removal of the example dcmap attribute line o In Section 5.1 removal of the example dcmap attribute line
'a=dcmap:2 subprotocol="BFCP";label="channel 2' as there are 'a=dcmap:2 subprotocol="BFCP";label="channel 2' as there are
already four examples right after the ABNF rules in already four examples right after the ABNF rules in Section 5.1.1.
Section 5.1.1.1. Corresponding removal of following related note: Corresponding removal of following related note: "Note: This
"Note: This document does not provide a complete specification of document does not provide a complete specification of how to
how to negotiate the use of a WebRTC data channel to transport negotiate the use of a WebRTC data channel to transport BFCP.
BFCP. Procedures specific to each subprotocol such as BFCP will Procedures specific to each subprotocol such as BFCP will be
be documented elsewhere. The use of BFCP is only an example of documented elsewhere. The use of BFCP is only an example of how
how the generic procedures described herein might apply to a the generic procedures described herein might apply to a specific
specific subprotocol." subprotocol."
o In Section 5.1.1 removal of following note: "Note: This attribute o In Section 5.1 removal of following note: "Note: This attribute is
is derived from attribute "webrtc-DataChannel", which was defined derived from attribute "webrtc-DataChannel", which was defined in
in old version 03 of the following draft, but which was removed old version 03 of the following draft, but which was removed along
along with any support for SDP external negotiation in subsequent with any support for SDP external negotiation in subsequent
versions: [I-D.ietf-mmusic-sctp-sdp]." versions: [I-D.ietf-mmusic-sctp-sdp]."
o Insertion of following new sentence to the beginning of o Insertion of following new sentence to the beginning of
Section 5.1.1.1: "dcmap is a media level attribute having Section 5.1.1: "dcmap is a media level attribute having following
following ABNF syntax:" ABNF syntax:"
o Insertion of new Section 5.1.1.3 containing the dcmap-stream-id o Insertion of new Section 5.1.2 containing the dcmap-stream-id
specifying sentence, which previously was placed right before the specifying sentence, which previously was placed right before the
formal ABNF rules. Removal of the sentence 'Stream is a mandatory formal ABNF rules. Removal of the sentence 'Stream is a mandatory
parameter and is noted directly after the "a=dcmap:" attribute's parameter and is noted directly after the "a=dcmap:" attribute's
colon' as this information is part of the ABNF specification. colon' as this information is part of the ABNF specification.
o In Section 5.1.1.1 modification of the 'ordering-value' values o In Section 5.1.1 modification of the 'ordering-value' values from
from "0" or "1" to "true" or "false". Corresponding text "0" or "1" to "true" or "false". Corresponding text modifications
modifications in Section 5.1.1.8. in Section 5.1.7.
o In Section 5.1.1.1 the ABNF definition of "quoted-string" referred o In Section 5.1.1 the ABNF definition of "quoted-string" referred
to rule name "escaped-char", which was not defined. Instead a to rule name "escaped-char", which was not defined. Instead a
rule with name "escaped" was defined. Renamed that rule's name to rule with name "escaped" was defined. Renamed that rule's name to
"escaped-char". "escaped-char".
o Insertion of a dedicated note right after the "a=dcmap:4" o Insertion of a dedicated note right after the "a=dcmap:4"
attribute example in Section 5.1.1.1 regarding the non-printable attribute example in Section 5.1.1 regarding the non-printable
"escaped-char" character within the "label" value. "escaped-char" character within the "label" value.
o In Section 5.1.2's second paragraph replacement of "sctp stream o In Section 5.2's second paragraph replacement of "sctp stream
identifier" with "SCTP stream identifier". identifier" with "SCTP stream identifier".
o In first paragraph of Section 6.1 replacement of first two o In first paragraph of Section 6.1 replacement of first two
sentences 'For the SDP-based external negotiation described in sentences 'For the SDP-based external negotiation described in
this document, the initial offerer based "SCTP over DTLS" owns by this document, the initial offerer based "SCTP over DTLS" owns by
convention the even stream identifiers whereas the initial convention the even stream identifiers whereas the initial
answerer owns the odd stream identifiers. This ownership is answerer owns the odd stream identifiers. This ownership is
invariant for the whole lifetime of the signaling session, e.g. it invariant for the whole lifetime of the signaling session, e.g. it
does not change if the initial answerer sends a new offer to the does not change if the initial answerer sends a new offer to the
initial offerer.' with 'If an SDP offer/answer exchange (could be initial offerer.' with 'If an SDP offer/answer exchange (could be
skipping to change at page 34, line 38 skipping to change at page 34, line 38
SDP offer. Note that the typical parser normally ignores unknown SDP offer. Note that the typical parser normally ignores unknown
SDP attributes, which includes data channel related attributes." SDP attributes, which includes data channel related attributes."
o In Section 6.3 the second sentence of the third SDP answerer o In Section 6.3 the second sentence of the third SDP answerer
action was "Note that the browser is asked to create data channels action was "Note that the browser is asked to create data channels
with stream identifiers not "owned" by the agent.". Replacement with stream identifiers not "owned" by the agent.". Replacement
of this sentence with "Note that the agent is asked to create data of this sentence with "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."
o In Section 6.6 the third paragraph began with "A data channel can o In Section 6.6.1 the third paragraph began with "A data channel
be closed by sending a new SDP offer which excludes the dcmap and can be closed by sending a new SDP offer which excludes the dcmap
dcsa attribute lines for the data channel. The port value for the and dcsa attribute lines for the data channel. The port value for
m line SHOULD NOT be changed (e.g., to zero) when closing a data the m line SHOULD NOT be changed (e.g., to zero) when closing a
channel (unless all data channels are being closed and the SCTP data channel (unless all data channels are being closed and the
association is no longer needed), since this would close the SCTP SCTP association is no longer needed), since this would close the
association and impact all of the data channels. If the answerer SCTP association and impact all of the data channels. If the
accepts the SDP offer then it MUST also exclude the corresponding answerer accepts the SDP offer then it MUST also exclude the
attribute lines in the answer. ..." Replacement of this part with corresponding attribute lines in the answer. ..." Replacement of
"The intention to close a data channel can be signaled by sending this part with "The intention to close a data channel can be
a new SDP offer which excludes the "a=dcmap:" and "a=dcsa:" signaled by sending a new SDP offer which excludes the "a=dcmap:"
attribute lines for the data channel. The port value for the "m" and "a=dcsa:" attribute lines for the data channel. The port
line SHOULD NOT be changed (e.g., to zero) when closing a data value for the "m" line SHOULD NOT be changed (e.g., to zero) when
channel (unless all data channels are being closed and the SCTP closing a data channel (unless all data channels are being closed
association is no longer needed), since this would close the SCTP and the SCTP association is no longer needed), since this would
association and impact all of the data channels. If the answerer close the SCTP association and impact all of the data channels.
accepts the SDP offer then it MUST close those data channels whose If the answerer accepts the SDP offer then it MUST close those
"a=dcmap:" and "a=dcsa:" attribute lines were excluded from the data channels whose "a=dcmap:" and "a=dcsa:" attribute lines were
received SDP offer, unless those data channels were already excluded from the received SDP offer, unless those data channels
closed, and it MUST also exclude the corresponding attribute lines were already closed, and it MUST also exclude the corresponding
in the answer." attribute lines in the answer."
o In Section 6.6 the hanging text after the third paragraph was o In Section 6.6.1 the hanging text after the third paragraph was
"This delayed close is to handle cases where a successful SDP "This delayed close is to handle cases where a successful SDP
answer is not received, in which case the state of session should answer is not received, in which case the state of session should
be kept per the last successful SDP offer/answer." Replacement of be kept per the last successful SDP offer/answer." Replacement of
this sentence with "This delayed closure is RECOMMENDED in order this sentence with "This delayed closure is RECOMMENDED in order
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 contained already procedural descriptions related to
data channel reliability negotiation. Creation of new Section 6.2 data channel reliability negotiation. Creation of new Section 6.2
and moval of reliability negotiation related text to this new and moval of reliability negotiation related text to this new
section. section.
11.16. Changes against 'draft-ejzak-mmusic-data-channel-sdpneg-02' 11.16. 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.
o Clarification of the semantic if the "max-retr" parameter is not o Clarification of the semantic if the "max-retr" parameter is not
present in an a=dcmap attribute line. In section "max-retr present in an a=dcmap attribute line. In section "max-retr
skipping to change at page 37, line 24 skipping to change at page 37, line 24
[I-D.ietf-mmusic-sctp-sdp] [I-D.ietf-mmusic-sctp-sdp]
Holmberg, C., Shpount, R., Loreto, S., and G. Camarillo, Holmberg, C., Shpount, R., Loreto, S., and G. Camarillo,
"Session Description Protocol (SDP) Offer/Answer "Session Description Protocol (SDP) Offer/Answer
Procedures For Stream Control Transmission Protocol (SCTP) Procedures For Stream Control Transmission Protocol (SCTP)
over Datagram Transport Layer Security (DTLS) Transport.", over Datagram Transport Layer Security (DTLS) Transport.",
draft-ietf-mmusic-sctp-sdp-26 (work in progress), April draft-ietf-mmusic-sctp-sdp-26 (work in progress), April
2017. 2017.
[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-16 Multiplexing", draft-ietf-mmusic-sdp-mux-attributes-17
(work in progress), December 2016. (work in progress), February 2018.
[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.
[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 38, line 20 skipping to change at page 38, line 20
[I-D.ietf-mmusic-dtls-sdp] [I-D.ietf-mmusic-dtls-sdp]
Holmberg, C. and R. Shpount, "Session Description Protocol Holmberg, C. and R. Shpount, "Session Description Protocol
(SDP) Offer/Answer Considerations for Datagram Transport (SDP) Offer/Answer Considerations for Datagram Transport
Layer Security (DTLS) and Transport Layer Security (TLS)", Layer Security (DTLS) and Transport Layer Security (TLS)",
draft-ietf-mmusic-dtls-sdp-32 (work in progress), October draft-ietf-mmusic-dtls-sdp-32 (work in progress), October
2017. 2017.
[I-D.ietf-mmusic-msrp-usage-data-channel] [I-D.ietf-mmusic-msrp-usage-data-channel]
Drage, K., Makaraju, M., Stoetzer-Bradler, J., Ejzak, R., Drage, K., Makaraju, M., Stoetzer-Bradler, J., Ejzak, R.,
and J. Marcon, "MSRP over Data Channels", draft-ietf- Marcon, J., and J. Recio, "MSRP over Data Channels",
mmusic-msrp-usage-data-channel-07 (work in progress), draft-ietf-mmusic-msrp-usage-data-channel-08 (work in
September 2017. progress), March 2018.
[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.
[IANA-SDP-Parameters] [IANA-SDP-Parameters]
"Session Description Protocol (SDP) Parameters", Internet "Session Description Protocol (SDP) Parameters", Internet
Assigned Numbers Authority Protocol Assignments Session Assigned Numbers Authority Protocol Assignments Session
Description Protocol (SDP) Parameters, Description Protocol (SDP) Parameters,
skipping to change at page 42, line 25 skipping to change at page 42, line 25
Email: Juergen.S-B.ietf@email.de Email: Juergen.S-B.ietf@email.de
Richard Ejzak Richard Ejzak
Unaffiliated Unaffiliated
Email: richard.ejzak@gmail.com Email: richard.ejzak@gmail.com
Jerome Marcon Jerome Marcon
Unaffiliated Unaffiliated
Email: jeromee.marcon@free.fr
Roni Even (editor) Roni Even (editor)
Huawei Huawei
Email: roni.even@huawei.com Email: roni.even@huawei.com
 End of changes. 86 change blocks. 
185 lines changed or deleted 197 lines changed or added

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