



CLUE Working Group                                           C. Holmberg
Internet-Draft                                                  Ericsson
Intended status: Experimental                             April 24, 2019
Expires: October 26, 2019


                       CLUE Protocol data channel
                     draft-ietf-clue-datachannel-18

Abstract

   This document defines how to use the WebRTC data channel mechanism to
   realize a data channel, referred to as a CLUE data channel, for
   transporting CLUE protocol messages between two CLUE entities.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on October 26, 2019.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.





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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  CLUE data channel . . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  General . . . . . . . . . . . . . . . . . . . . . . . . .   3
     3.2.  SCTP Considerations . . . . . . . . . . . . . . . . . . .   4
       3.2.1.  General . . . . . . . . . . . . . . . . . . . . . . .   4
       3.2.2.  SCTP Payload Protocol Identifier (PPID) . . . . . . .   4
       3.2.3.  Reliability . . . . . . . . . . . . . . . . . . . . .   4
       3.2.4.  Order . . . . . . . . . . . . . . . . . . . . . . . .   5
       3.2.5.  Stream Reset  . . . . . . . . . . . . . . . . . . . .   5
       3.2.6.  SCTP Multihoming  . . . . . . . . . . . . . . . . . .   5
       3.2.7.  Closing the CLUE data channel . . . . . . . . . . . .   5
     3.3.  SDP Considerations  . . . . . . . . . . . . . . . . . . .   5
       3.3.1.  General . . . . . . . . . . . . . . . . . . . . . . .   5
       3.3.2.  SDP dcmap Attribute . . . . . . . . . . . . . . . . .   6
       3.3.3.  SDP dcsa Attribute  . . . . . . . . . . . . . . . . .   7
       3.3.4.  Example . . . . . . . . . . . . . . . . . . . . . . .   7
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
     5.1.  New WebRTC data channel Protocol Value  . . . . . . . . .   8
   6.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   8
   7.  Change Log  . . . . . . . . . . . . . . . . . . . . . . . . .   8
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  12
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  13
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   This document defines how to use the WebRTC data channel mechanism
   [I-D.ietf-rtcweb-data-channel] to realize a data channel, referred to
   as a CLUE data channel, for transporting CLUE protocol
   [I-D.ietf-clue-protocol] messages between two CLUE entities.

   The document defines how to describe the SCTPoDTLS association
   [RFC8261] used to realize the CLUE data channel using the Session
   Description Protocol (SDP) [RFC4566], and defines usage of the SDP-
   based "SCTP over DTLS" data channel negotiation mechanism
   [I-D.ietf-mmusic-data-channel-sdpneg].  This includes SCTP
   considerations specific to a CLUE data channel, the SDP Media
   Description ("m=" line) values, and usage of SDP attributes specific
   to a CLUE data channel.

   Details and procedures associated with the CLUE protocol, and the SDP
   Offer/Answer [RFC3264] procedures for negotiating usage of a CLUE
   data channel, are outside the scope of this document.



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   NOTE: The usage of the Data Channel Establishment Protocol (DCEP)
   [I-D.ietf-rtcweb-data-protocol] for establishing a CLUE data channel
   is outside the scope of this document.

2.  Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   SCTPoDTLS association refers to an SCTP association carried over an
   DTLS connection [RFC8261].

   WebRTC data channel refers to a pair of SCTP streams over a SCTPoDTLS
   association that is used to transport non-media data between two
   entities, as defined in [I-D.ietf-rtcweb-data-channel].

   CLUE data channel refers to a WebRTC data channel
   [I-D.ietf-rtcweb-data-channel] realization, with a specific set of
   SCTP characteristics, with the purpose of transporting CLUE protocol
   [I-D.ietf-clue-protocol] messages between two CLUE entities.

   CLUE entity refers to a SIP User Agent (UA) [RFC3261] that supports
   the CLUE data channel and the CLUE protocol.

   CLUE session refers to a SIP session [RFC3261] between two SIP UAs,
   where a CLUE data channel, associated with the SIP session, has been
   established between the SIP UAs.

   SCTP stream is defined in [RFC4960] as a unidirectional logical
   channel established from one to another associated SCTP endpoint,
   within which all user messages are delivered in sequence except for
   those submitted to the unordered delivery service.

   SCTP identifier is defined in [RFC4960] as an unsigned integer, which
   identifies an SCTP stream.

3.  CLUE data channel

3.1.  General

   This section describes the realization of a CLUE data channel, using
   the WebRTC data channel mechanism.  This includes a set of SCTP
   characteristics specific to a CLUE data channel, the values of the
   "m=" line describing the SCTPoDTLS association associated with the
   WebRTC data channel, and the usage of the SDP-based "SCTP over DTLS"



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   data channel negotiation mechanism for creating the CLUE data
   channel.

   As described in [I-D.ietf-rtcweb-data-channel], the SCTP streams
   realizing a WebRTC data channel must be associated with the same SCTP
   association.  In addition, both SCTP streams realizing the WebRTC
   data channel must use the same SCTP stream identifier value.  These
   rules also apply to a CLUE data channel.

   Within a given CLUE session, a CLUE entity MUST use a single CLUE
   data channel for transport of all CLUE messages towards its peer.

3.2.  SCTP Considerations

3.2.1.  General

   As described in [I-D.ietf-rtcweb-data-channel], different SCTP
   options (e.g., regarding ordered delivery ), can be used for a data
   channel.  This section describes the SCTP options used for a CLUE
   data channel.  Section 3.3 describes how SCTP options are signaled
   using SDP.

   NOTE: While SCTP allows SCTP options to be applied per SCTP message,
   [I-D.ietf-rtcweb-data-channel] mandates that, for a given data
   channel, the same SCTP options are applied to each SCTP message
   associated with that data channel.

3.2.2.  SCTP Payload Protocol Identifier (PPID)

   A CLUE entity MUST use the PPID value 51 when sending a CLUE message
   on a CLUE data channel.

   NOTE: As described in [I-D.ietf-rtcweb-data-channel], the PPID value
   51 indicates that the SCTP message contains data encoded in a UTF-8
   format.  The PPID value 51 does not indicate which application
   protocol the SCTP message is associated with, only the format in
   which the data is encoded.

3.2.3.  Reliability

   The usage of SCTP for the CLUE data channel ensures reliable
   transport of CLUE protocol [I-D.ietf-clue-protocol] messages.

   [I-D.ietf-rtcweb-data-channel] requires the support of the partial
   reliability extension defined in [RFC3758] and the limited
   retransmission policy defined in [RFC7496].  A CLUE entity MUST NOT
   use these extensions, as messages are required to always be sent




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   reliably.  A CLUE entity MUST terminate the session if it detects
   that the peer entity uses any of the extensions.

3.2.4.  Order

   A CLUE entity MUST use the ordered delivery SCTP service, as
   described in [RFC4960], for the CLUE data channel.

3.2.5.  Stream Reset

   A CLUE entity MUST support the stream reset extension defined in
   [RFC6525].

   As defined in [I-D.ietf-rtcweb-data-channel], the dynamic address
   reconfiguration extension ('Supported Extensions Parameter'
   parameter) defined in [RFC5061] must be used to signal the support of
   the stream reset extension defined in [RFC6525].  Other features of
   [RFC5061] MUST NOT be used for CLUE data channels.

3.2.6.  SCTP Multihoming

   SCTP multi-homing is not supported for SCTPoDTLS associations, and
   can therefore not be used for a CLUE data channel.

3.2.7.  Closing the CLUE data channel

   As described in [I-D.ietf-rtcweb-data-channel], to close a data
   channel, an entity sends an SCTP reset message [RFC6525] on its
   outgoing SCTP stream associated with the data channel.  When the
   remote peer receives the reset message, it also sends (unless already
   sent) a reset message on its outgoing SCTP stream associated with the
   data channel.  The SCTPoDTLS association, and other data channels
   established on the same association, are not affected by the SCTP
   reset messages.

3.3.  SDP Considerations

3.3.1.  General

   This section defines how to construct the SDP Media Description ("m="
   line) for describing the SCTPoDTLS association used to realize a CLUE
   data channel.  The section also defines how to use the SDP-based
   "SCTP over DTLS" data channel negotiation mechanism
   [I-D.ietf-mmusic-data-channel-sdpneg] for establishing a CLUE data
   channel on the SCTPoDTLS association.






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   NOTE: Other protocols than SDP for negotiating usage of an SCTPoDTLS
   association for realizing a CLUE data channel are outside the scope
   of this specification.

   [I-D.ietf-clue-signaling] describes the SDP Offer/Answer procedures
   for negotiating a CLUE session, including the CLUE controlled media
   streams and the CLUE data channel.

3.3.1.1.  SDP Media Description Fields

   [I-D.ietf-mmusic-sctp-sdp] defines how to set the values of an "m="
   line describing an SCTPoDTLS association.  As defined in
   [I-D.ietf-mmusic-sctp-sdp], for a CLUE data channel the values are
   set as following:

   +---------------+----------+-----------------+----------------------+
   |     media     |   port   |      proto      |         fmt          |
   +---------------+----------+-----------------+----------------------+
   | "application" | UDP port | "UDP/DTLS/SCTP" | "webrtc-datachannel" |
   |               |  value   |                 |                      |
   | "application" | TCP port | "TCP/DTLS/SCTP" | "webrtc-datachannel" |
   |               |  value   |                 |                      |
   +---------------+----------+-----------------+----------------------+

                     Table 1: SDP "proto" field values

   CLUE entities SHOULD NOT transport the SCTPoDTLS association used to
   realize the CLUE data channel over TCP (using the "TCP/DTLS/SCTP"
   proto value), unless it is known that UDP/DTLS/SCTP will not work
   (for instance, when the Interactive Connectivity Establishment (ICE)
   mechanism [RFC8445] is used and the ICE procedures determine that TCP
   transport is required).

3.3.1.2.  SDP sctp-port Attribute

   As defined in [I-D.ietf-mmusic-sctp-sdp], the SDP sctp-port attribute
   value is set to the SCTP port of the SCTPoDTLS association.  A CLUE
   entity can choose any valid SCTP port value
   [I-D.ietf-mmusic-sctp-sdp].

3.3.2.  SDP dcmap Attribute

   The values of the SDP dcmap attribute
   [I-D.ietf-mmusic-data-channel-sdpneg], associated with the "m=" line
   describing the SCTPoDTLS association used to realize the WebRTC data
   channel, are set as following:





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   +----------+------------+------------+--------+----------+----------+
   | stream-  |    sub-    |   label    | ordere | max-retr | max-time |
   |    id    |  protocol  |            |   d    |          |          |
   +----------+------------+------------+--------+----------+----------+
   | Value of |   "CLUE"   |   Appli-   | "true" |   N/A    |   N/A    |
   | the SCTP |            |   cation   |        |          |          |
   |  stream  |            |  specific  |        |          |          |
   | used to  |            |            |        |          |          |
   | realize  |            |            |        |          |          |
   | the CLUE |            |            |        |          |          |
   |   data   |            |            |        |          |          |
   | channel  |            |            |        |          |          |
   +----------+------------+------------+--------+----------+----------+

                    Table 2: SDP dcmap attribute values

   NOTE: As CLUE entities are required to use ordered SCTP message
   delivery, with full reliability, according to the procedures in
   [I-D.ietf-mmusic-data-channel-sdpneg] the max-retr and max-time
   attribute parameters are not used when negotiating CLUE data
   channels.

3.3.3.  SDP dcsa Attribute

   The SDP dcsa attribute [I-D.ietf-mmusic-data-channel-sdpneg] is not
   used when establishing a CLUE data channel.

3.3.4.  Example

   The example in Figure 1 shows an SDP media description for a CLUE
   data channel.  Examples of complete SDP examples can be found in
   [I-D.ietf-clue-signaling].


           m=application 54111 UDP/DTLS/SCTP webrtc-datachannel
           a=sctp-port: 5000
           a=dcmap:2 subprotocol="CLUE";ordered=true


          Figure 1: SDP Media Description for a CLUE data channel

4.  Security Considerations

   This specification relies on the security properties of the WebRTC
   data channel described in [I-D.ietf-rtcweb-data-channel], including
   reliance on DTLS.  Since CLUE sessions are established using SIP/SDP,
   protecting the data channel against message modification and recovery
   requires the use of SIP authentication and authorization mechanisms



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   described in [RFC3261] for session establishment prior to
   establishing the data channel.

5.  IANA Considerations

5.1.  New WebRTC data channel Protocol Value

   [RFC EDITOR NOTE: Please replace RFC-XXXX with the RFC number of this
   document.]

   This document adds the 'CLUE' value to the "WebSocket Subprotocol
   Name Registry" as follows:


           Subprotocl Identifier:          CLUE
           Subprotocol Common Name:        CLUE
           Subprotocol Definition:         RFC-XXXX
       Reference:                  RFC-XXXX


6.  Acknowledgments

   Thanks to Paul Kyzivat, Christian Groves and Mark Duckworth for
   comments on the document.

7.  Change Log

   [RFC EDITOR NOTE: Please remove this section when publishing]

   Changes from draft-ietf-clue-datachannel-17

   o  Editorial changes to Tables based on TSV-ART review.

   Changes from draft-ietf-clue-datachannel-16

   o  Category changed to Experimental.

   Changes from draft-ietf-clue-datachannel-15

   o  Updates based on IESG review by Roman Danyliw.
   o  Make CLUE references Informative, as they are going to be
      published as Experimental RFCs.

   Changes from draft-ietf-clue-datachannel-14

   o  ICE reference update.
   o  Reference draft versions updates.




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   Changes from draft-ietf-clue-datachannel-13

   o  Editorial changes based on Gen-ART review from Brian Carpenter.

   Changes from draft-ietf-clue-datachannel-12

   o  Changes based on AD comments from Alissa Cooper
      (https://www.ietf.org/mail-archive/web/clue/current/
      msg04911.html):
   o  - DCEP reference removed from security considerations.
   o  - Editorial fixes.
   o  - NOTE: Comment regarding the Security Considerations is still
      pending.

   Changes from draft-ietf-clue-datachannel-11

   o  Changes based on WGLC comments from Juergen Stoetzer-Bradler and
      Christian groves:
   o  - Reference updates.
   o  - 'Reference' added to IANA registration data.

   Changes from draft-ietf-clue-datachannel-10

   o  Security Considerations modified and enhanced, based on comments
      provided by Alissa Cooper.

   Changes from draft-ietf-clue-datachannel-09

   o  Reference updates:
   o  - draft-ietf-tsvwg-sctp-prpolicies published as RFC 7496
   o  - Reference update of draft versions

   Changes from draft-ietf-clue-datachannel-08

   o  Changes based on WGLC comments from Daniel Burnett:
   o  - Editorial corrections.
   o  Changes based on WGLC comments from Paul Kyzivat:
   o  - Editorial corrections.

   Changes from draft-ietf-clue-datachannel-07

   o  Changes based on WGLC comments from Christian Groves:
   o  - IANA considerations for dcmap attribute removed.
   o  - Explicit clarification that the dcmap attribute max-time and
      max-retr parameters are not used with ordered/reliable
      transmission of SCTP messages.
   o  - Indication that TCP transport should only be used if ICE is
      used, and if usage of TCP is required by ICE.



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   o  - Informative reference to ICE added.
   o  - Editorial corrections.
   o  Changes based on WGLC comments from Mark Duckworth:
   o  - Make it more clear that the rules regarding usage of partial
      reliability and ordered reliability apply to CLUE data channels.
   o  Changes based on WGLC comments from Paul Kyzivat:
   o  - Clarify that same SCTP options are applied to each SCTP message
      associated with a given data channel.
   o  - Switched location of sections 3.2 and 3.3.
   o  - PPID table removed.  Not needed, since only one value is used.
   o  - Editorial corrections.

   Changes from draft-ietf-clue-datachannel-06

   o  Usage of DCEP removed.

   Changes from draft-ietf-clue-datachannel-05

   o  "DTLS/SCTP" split into "UDP/DTLS/SCTP" and "TCP/DTLS/SCTP".
   o  Removed note regarding optionality of including the SDP sctp-port
      attribute.
   o  Added defintion of 'SCTPoDTLS association' to the Conventions.
   o  Reference to RFC 4566 (SDP) added.

   Changes from draft-ietf-clue-datachannel-04

   o  Defines DCEP and external SDP negotiation as two separate
      mechanisms for negotiating a CLUE data channel.
   o  Updates based on technical changes in referenced specifications.
   o  Reference to draft-ietf-mmusic-sctp-sdp added.

   Changes from draft-ietf-clue-datachannel-03

   o  IANA considerations added.
   o  Editorial changes based on comments from Christian Groves.

   Changes from draft-ietf-clue-datachannel-02

   o  SDP "m=" line example fixed.
   o  OPEN ISSUE #1 closed.
   o  - It was agreed (IETF#91) to use draft-ejzak-mmusic-data-channel-
      sdpneg, as it was adopted as a WG item in MMUSIC.
   o  - Details for draft-ejzak-mmusic-data-channel-sdpneg usage added.
   o  SDP Offer/Answer procedures removed, as they will be defined in
      the CLUE protocol draft.
   o  References updated.

   Changes from draft-ietf-clue-datachannel-01



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   o  Support of interleaving "MUST"->"SHOULD".
   o  Example updated.
   o  Reference update.

   Changes from draft-ietf-clue-datachannel-00

   o  SDP Offer/Answer procedures structures according to RFC 3264.
   o  Reference update.

   Changes from draft-holmberg-clue-datachannel-04

   o  Draft submitted as draft-ietf-clue-data-channel-00.
   o  Editorial nits fixed.
   o  Changes based on comments from Paul Kyzivat (http://www.ietf.org/
      mail-archive/web/clue/current/msg03559.html).
   o  - Proto value fixed.
   o  - Explicit text that the partial reliability and limited
      retransmission policies MUST NOT be used.
   o  - Added open issue on whether the DCEP 'protocol' field value for
      CLUE should contain a version number.
   o  - Removed paragraph saying that an offerer must not insert more
      than one "m=" line describing an SCTPoDTLS association to be used
      to realize a CLUE data channel, as the draft already states that
      only one CLUE data channel per CLUE session shall be opened.
   o  - Added reference to draft-ietf-rtcweb-data-protocol regarding
      details on reseting SCTP streams.
   o  - Added text saying that the value of the DCEP 'channel type' MUST
      be DATA_CHANNEL_RELIABLE.
   o  - Clarified that DCEP must be supported, and used in the absence
      of another mechanism for opening a CLUE data channel.

   Changes from draft-holmberg-clue-datachannel-03

   o  Procedures updated, based on WG agreement (IETF#89) to use DCEP
      for the CLUE data channel.
   o  Procedures updated, based on WG agreement (IETF#89) that offerer
      is responsible for sending DCEP DATA_CHANNEL_OPEN.
   o  Editorial changes, and alignments caused by changes in referenced
      specifications.

   Changes from draft-holmberg-clue-datachannel-02

   o  PPID value for CLUE messages added
   o  References updated

   Changes from draft-holmberg-clue-datachannel-01

   o  More text added



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   Changes from draft-holmberg-clue-datachannel-00

   o  Editorial corrections based on comments from Paul K

8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997, <https://www.rfc-
              editor.org/info/rfc2119>.

   [RFC3261]  Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
              A., Peterson, J., Sparks, R., Handley, M., and E.
              Schooler, "SIP: Session Initiation Protocol", RFC 3261,
              DOI 10.17487/RFC3261, June 2002, <https://www.rfc-
              editor.org/info/rfc3261>.

   [RFC3264]  Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model
              with Session Description Protocol (SDP)", RFC 3264,
              DOI 10.17487/RFC3264, June 2002, <https://www.rfc-
              editor.org/info/rfc3264>.

   [RFC4566]  Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
              Description Protocol", RFC 4566, DOI 10.17487/RFC4566,
              July 2006, <https://www.rfc-editor.org/info/rfc4566>.

   [RFC4960]  Stewart, R., Ed., "Stream Control Transmission Protocol",
              RFC 4960, DOI 10.17487/RFC4960, September 2007,
              <https://www.rfc-editor.org/info/rfc4960>.

   [RFC5061]  Stewart, R., Xie, Q., Tuexen, M., Maruyama, S., and M.
              Kozuka, "Stream Control Transmission Protocol (SCTP)
              Dynamic Address Reconfiguration", RFC 5061,
              DOI 10.17487/RFC5061, September 2007, <https://www.rfc-
              editor.org/info/rfc5061>.

   [RFC6525]  Stewart, R., Tuexen, M., and P. Lei, "Stream Control
              Transmission Protocol (SCTP) Stream Reconfiguration",
              RFC 6525, DOI 10.17487/RFC6525, February 2012,
              <https://www.rfc-editor.org/info/rfc6525>.

   [RFC7496]  Tuexen, M., Seggelmann, R., Stewart, R., and S. Loreto,
              "Additional Policies for the Partially Reliable Stream
              Control Transmission Protocol Extension", RFC 7496,
              DOI 10.17487/RFC7496, April 2015, <https://www.rfc-
              editor.org/info/rfc7496>.



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   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8261]  Tuexen, M., Stewart, R., Jesup, R., and S. Loreto,
              "Datagram Transport Layer Security (DTLS) Encapsulation of
              SCTP Packets", RFC 8261, DOI 10.17487/RFC8261, November
              2017, <https://www.rfc-editor.org/info/rfc8261>.

   [I-D.ietf-mmusic-sctp-sdp]
              Holmberg, C., Loreto, S., and G. Camarillo, "Stream
              Control Transmission Protocol (SCTP)-Based Media Transport
              in the Session Description Protocol (SDP)", draft-ietf-
              mmusic-sctp-sdp-26.txt (work in progress), April 2017.

   [I-D.ietf-rtcweb-data-channel]
              Jesup, R., Loreto, S., and M. Tuexen, "WebRTC data
              channels", draft-ietf-rtcweb-data-channel-13.txt (work in
              progress), January 2015.

   [I-D.ietf-mmusic-data-channel-sdpneg]
              Drage, K., Makaraju, R., Stoetzer-Bradler, J., Ejzak, R.,
              and J. Marcon, "SDP-based "SCTP over DTLS" data channel
              negotiation", draft-ietf-mmusic-data-channel-sdpneg-26.txt
              (work in progress), April 2019.

8.2.  Informative References

   [RFC3758]  Stewart, R., Ramalho, M., Xie, Q., Tuexen, M., and P.
              Conrad, "Stream Control Transmission Protocol (SCTP)
              Partial Reliability Extension", RFC 3758,
              DOI 10.17487/RFC3758, May 2004, <https://www.rfc-
              editor.org/info/rfc3758>.

   [RFC8445]  Keranen, A., Holmberg, C., and J. Rosenberg, "Interactive
              Connectivity Establishment (ICE): A Protocol for Network
              Address Translator (NAT) Traversal", RFC 8445,
              DOI 10.17487/RFC8445, July 2018, <https://www.rfc-
              editor.org/info/rfc8445>.

   [I-D.ietf-rtcweb-data-protocol]
              Jesup, R., Loreto, S., and M. Tuexen, "WebRTC data channel
              Establishment Protocol", draft-ietf-rtcweb-data-protocol-
              09.txt (work in progress), January 2015.

   [I-D.ietf-clue-protocol]
              Presta, R. and S. Romano, "CLUE protocol", draft-ietf-
              clue-protocol-17.txt (work in progress), September 2018.



Holmberg                Expires October 26, 2019               [Page 13]

Internet-Draft              CLUE data channel                 April 2019


   [I-D.ietf-clue-signaling]
              Kyzivat, P., Xiao, L., Groves, C., and S. Romano, "CLUE
              Signaling", draft-ietf-clue-signaling-14.txt (work in
              progress), October 2018.

Author's Address

   Christer Holmberg
   Ericsson
   Hirsalantie 11
   Jorvas  02420
   Finland

   Email: christer.holmberg@ericsson.com





































Holmberg                Expires October 26, 2019               [Page 14]
