CLUE Working Group C. Holmberg
Internet-Draft Ericsson
Intended status: Standards Track February 7, 2014
Expires: August 11, 2014
CLUE Protocol Data Channel
draft-holmberg-clue-datachannel-01
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
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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 . . . . . . . . . . . . . . . . . . . . . . . . 4
3.4.4. Stream Reset . . . . . . . . . . . . . . . . . . . . 4
3.4.5. Interleaving . . . . . . . . . . . . . . . . . . . . 5
3.4.6. SCTP Multihoming . . . . . . . . . . . . . . . . . . 5
4. SDP Offer/Answer Procedures . . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 5
8. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 5
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
9.1. Normative References . . . . . . . . . . . . . . . . . . 5
9.2. Informative References . . . . . . . . . . . . . . . . . 6
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6
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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The SCTP streams MUST have identical SCTP stream identifier values,
unless a specific value is already used for some other purpose.
OPEN ISSUE: 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: It is FFS whether the RTCWEB Data Channel Protocol will
be used in the CLUE context.
3.4. SCTP Considerations
3.4.1. SCTP Payload Protocol Identifier (PPID)
CLUE entities MUST use a PPID value of 51 or 54, according to the
procedures in [I-D.ietf-rtcweb-data-channel].
NOTE: As described in [I-D.ietf-rtcweb-data-channel], the PPID values
are used to indicate that the SCTP message contains data encoded in a
DOMstring format [reference-needed].
3.4.2. Reliability
CLUE entities MUST use the reliable transport SCTP feature.
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[ref-to-tuexen-tsvwg-sctp-
prpolicies].
3.4.3. Order
CLUE entities MUST use the ordered delivery SCTP feature.
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.
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3.4.5. Interleaving
CLUE entities MUST support the message interleaving mechanism [ref-
to-tuexen-tsvwg-sctp-prpolicies].
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
TBD
5. Security Considerations
TBD
6. IANA Considerations
[RFC EDITOR NOTE: Please replace RFC-XXXX with the RFC number of this
document.]
7. Acknowledgments
TBD
8. Change Log
[RFC EDITOR NOTE: Please remove this section when publishing]
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.
[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.
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[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.
[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, "RTCWeb Data
Channels", draft-ietf-rtcweb-data-channel-06.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.
Author's Address
Christer Holmberg
Ericsson
Hirsalantie 11
Jorvas 02420
Finland
Email: christer.holmberg@ericsson.com
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