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Versions: 00 01 02 03 04 draft-ietf-clue-datachannel

CLUE Working Group                                           C. Holmberg
Internet-Draft                                                  Ericsson
Intended status: Standards Track                       February 12, 2014
Expires: August 16, 2014


                       CLUE Protocol Data Channel
                   draft-holmberg-clue-datachannel-03

Abstract

   This document specifies how to use the Stream Control Transmission
   Protocol (SCTP) on top of the Datagram Transport Layer Security
   (DTLS) protocol (SCTPoDTLS) for transporting CLUE protocol messages
   between CLUE entities.

   The document describes the SCTP considerations for CLUE, and the SDP
   Offer/Answer procedures for negotiating a SCTPoDTLS connection for
   CLUE.

   Details and procedures associated with the CLUE protocol are outside
   the scope of this document.

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
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   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 August 16, 2014.

Copyright Notice

   Copyright (c) 2014 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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   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Usage of SCTPoDTLS in the CLUE Context  . . . . . . . . . . .   3
     3.1.  General . . . . . . . . . . . . . . . . . . . . . . . . .   3
     3.2.  CLUE Data Channel Definition  . . . . . . . . . . . . . .   3
     3.3.  RTCWEB Data Channel Protocol Usage  . . . . . . . . . . .   4
     3.4.  SCTP Considerations . . . . . . . . . . . . . . . . . . .   4
       3.4.1.  SCTP Payload Protocol Identifier (PPID) . . . . . . .   4
       3.4.2.  Reliability . . . . . . . . . . . . . . . . . . . . .   4
       3.4.3.  Order . . . . . . . . . . . . . . . . . . . . . . . .   5
       3.4.4.  Stream Reset  . . . . . . . . . . . . . . . . . . . .   5
       3.4.5.  Interleaving  . . . . . . . . . . . . . . . . . . . .   5
       3.4.6.  SCTP Multihoming  . . . . . . . . . . . . . . . . . .   5
   4.  SDP Offer/Answer Procedures . . . . . . . . . . . . . . . . .   5
     4.1.  SDP-based WebRTC Data Channel Negotiation Usage . . . . .   5
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   6
   8.  Change Log  . . . . . . . . . . . . . . . . . . . . . . . . .   6
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   6
     9.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   This document specifies how to use the Stream Control Transmission
   Protocol (SCTP) on top of the Datagram Transport Layer Security
   (DTLS) protocol (SCTPoDTLS) for transporting CLUE protocol messages
   between CLUE entities.

   The document describes the SCTP considerations for CLUE, and the SDP
   Offer/Answer procedures for negotiating a SCTPoDTLS connection for
   CLUE.

   Details and procedures associated with the CLUE protocol are outside
   the scope of this document.





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2.  Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in BCP 14, RFC 2119
   [RFC2119].

   CLUE data channel refers to the SCTPoDTLS association that is used
   between two CLUE entities in order to transport CLUE messages.

   CLUE message refers to a CLUE protocol message that is sent over the
   CLUE data channel.

   CLUE entity refers to a SIP User Agent (UA) device that supports the
   CLUE mechanism (including the CLUE protocol).

   [RFC4960] defines a SCTP stream 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.

   [RFC4960] defines a SCTP identifier as a unsigned integer, which
   identifies an SCTP stream.

3.  Usage of SCTPoDTLS in the CLUE Context

3.1.  General

   This section defines the CLUE data channel, and describes the SCTP
   features and extensions used to realize it.

   The CLUE data channel realization, and set of SCTP features, are
   based on the the RTCWEB data channel defined in
   [I-D.ietf-rtcweb-data-channel].  This will allow CLUE entities to be
   interoperable with entities implementing
   [I-D.ietf-rtcweb-data-channel].

3.2.  CLUE Data Channel Definition

   The CLUE data channel is realized by using the Stream Control
   Transmission Protocol (SCTP) on top of the Datagram Transport Layer
   Security (DTLS) protocol [I-D.ietf-tsvwg-sctp-dtls-encaps].

   The realization of a bidirectional CLUE Data Channel is a pair of one
   incoming SCTP stream and one outgoing SCTP stream.  These streams are
   then used to transport CLUE messages in both directions.

   The SCTP streams MUST belong to the same SCTP association.



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   Within a given CLUE session, CLUE entities MUST use a single CLUE
   data channel for all CLUE messages associated with the CLUE session.

   The SCTP streams MUST have identical SCTP stream identifier values,
   unless a specific value is already used for some other purpose.

   OPEN ISSUE #1: The requirement to use identical STCP stream
   identifier values might be modified depending on what mechanism will
   be used to negotiate the identifier values.

3.3.  RTCWEB Data Channel Protocol Usage

   OPEN ISSUE #2: It is FFS whether the RTCWEB Data Channel Protocol
   [I-D.ietf-rtcweb-data-protocol] will be used with the CLUE data
   channel.

   NOTE: If [I-D.ietf-rtcweb-data-protocol] will be used with the CLUE
   data channel, a new associated 'protocol' value needs to be
   registered with IANA in the 'Protocol Registry' defined by
   [I-D.ietf-rtcweb-data-protocol].

3.4.  SCTP Considerations

3.4.1.  SCTP Payload Protocol Identifier (PPID)

   CLUE entities MUST use the PPID value 51 when sending CLUE messages,
   according to the procedures in [I-D.ietf-rtcweb-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 what protocol the SCTP
   message contains.

   NOTE: If the RTCWEB Data Channel Protocol
   [I-D.ietf-rtcweb-data-protocol]  will be used for the CLUE data
   channel, the PPID value 50 will be used for Data Channel Protocol
   messages.

3.4.2.  Reliability

   The usage of SCTP for the data channel ensures reliable transport of
   CLUE messages.

   NOTE: [I-D.ietf-rtcweb-data-channel] requires the support of the
   partial reliability extension defined in [RFC3758].  This is not
   needed for CLUE, as messages are required to always be sent reliably.
   [I-D.ietf-rtcweb-data-channel] also mandates support of the limited
   retransmission policy defined in [I-D.tuexen-tsvwg-sctp-prpolicies].



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3.4.3.  Order

   CLUE entities MUST use the ordered delivery SCTP service, as
   described in section 6.6 of [RFC2960].

3.4.4.  Stream Reset

   CLUE entities MUST support the stream reset extension defined in
   [RFC6525]

   The dynamic address reconfiguration extension 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.

3.4.5.  Interleaving

   CLUE entities MUST support the message interleaving mechanism defined
   in [I-D.stewart-tsvwg-sctp-ndata].

3.4.6.  SCTP Multihoming

   CLUE entities MUST NOT use SCTP multihoming.

   NOTE: The SCTPoDTLS mechanism does not support SCTP multihoming.

4.  SDP Offer/Answer Procedures

4.1.  SDP-based WebRTC Data Channel Negotiation Usage

   OPEN ISSUE #3: It is FFS whether the SDP-based WebRTC Data Channel
   Negotiation mechanism [I-D.ejzak-dispatch-webrtc-data-channel-sdpneg]
   will be used with the CLUE data channel.

   NOTE: If [I-D.ejzak-dispatch-webrtc-data-channel-sdpneg] will be used
   with the CLUE data channel, a new associated 'sub-protocol' value
   needs to be registered with IANA.

5.  Security Considerations

   TBD

6.  IANA Considerations

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






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7.  Acknowledgments

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

8.  Change Log

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

   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

   Changes from draft-holmberg-clue-datachannel-00

   o  Editorial corrections based on comments from Paul K

9.  References

9.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2960]  Stewart, R., Xie, Q., Morneault, K., Sharp, C.,
              Schwarzbauer, H., Taylor, T., Rytina, I., Kalla, M.,
              Zhang, L., and V. Paxson, "Stream Control Transmission
              Protocol", RFC 2960, October 2000.

   [RFC3261]  Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
              A., Peterson, J., Sparks, R., Handley, M., and E.
              Schooler, "SIP: Session Initiation Protocol", RFC 3261,
              June 2002.

   [RFC3264]  Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model
              with Session Description Protocol (SDP)", RFC 3264, June
              2002.

   [RFC4960]  Stewart, R., "Stream Control Transmission Protocol", RFC
              4960, September 2007.






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   [RFC5061]  Stewart, R., Xie, Q., Tuexen, M., Maruyama, S., and M.
              Kozuka, "Stream Control Transmission Protocol (SCTP)
              Dynamic Address Reconfiguration", RFC 5061, September
              2007.

   [RFC6525]  Stewart, R., Tuexen, M., and P. Lei, "Stream Control
              Transmission Protocol (SCTP) Stream Reconfiguration", RFC
              6525, February 2012.

   [I-D.ietf-tsvwg-sctp-dtls-encaps]
              Tuexen, M., Stewart, R., Jesup, R., and S. Loreto, "DTLS
              Encapsulation of SCTP Packets", draft-ietf-tsvwg-sctp-
              dtls-encaps-02.txt (work in progress), October 2013.

   [I-D.ietf-rtcweb-data-channel]
              Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data
              Channels", draft-ietf-rtcweb-data-channel-07.txt (work in
              progress), February 2014.

   [I-D.ietf-rtcweb-data-protocol]
              Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data Channel
              Establishment Protocol", draft-ietf-rtcweb-data-
              protocol-03.txt (work in progress), February 2014.

   [I-D.ejzak-dispatch-webrtc-data-channel-sdpneg]
              Ejzak, R. and J. Marcon, "SDP-based WebRTC data channel
              negotiation", draft-ejzak-dispatch-webrtc-data-channel-
              sdpneg-00.txt (work in progress), October 2013.

   [I-D.stewart-tsvwg-sctp-ndata]
              Stewart, R., Tuexen, M., Loreto, S., and R. Seggelmann, "A
              New Data Chunk for Stream Control Transmission Protocol",
              draft-stewart-tsvwg-sctp-ndata-03.txt (work in progress),
              October 2013.

   [I-D.tuexen-tsvwg-sctp-prpolicies]
              Tuexen, M., Seggelmann, R., Stewart, R., and S. Loreto,
              "Additional Policies for the Partial Delivery Extension of
              the Stream Control Transmission Protocol", draft-tuexen-
              tsvwg-sctp-prpolicies-03.txt (work in progress), October
              2013.

9.2.  Informative References

   [RFC3758]  Stewart, R., Ramalho, M., Xie, Q., Tuexen, M., and P.
              Conrad, "Stream Control Transmission Protocol (SCTP)
              Partial Reliability Extension", RFC 3758, May 2004.




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Author's Address

   Christer Holmberg
   Ericsson
   Hirsalantie 11
   Jorvas  02420
   Finland

   Email: christer.holmberg@ericsson.com










































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