| CLUE Working Group | C.H. Holmberg |
| Internet-Draft | Ericsson |
| Intended status: Standards Track | February 07, 2014 |
| Expires: August 11, 2014 |
CLUE Protocol Data Channel
draft-holmberg-clue-datachannel-01
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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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.
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.
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].
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.
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.
OPEN ISSUE: It is FFS whether the RTCWEB Data Channel Protocol will be used in the CLUE context.
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].
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].
CLUE entities MUST use the ordered delivery SCTP feature.
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.
CLUE entities MUST support the message interleaving mechanism [ref-to-tuexen-tsvwg-sctp-prpolicies].
CLUE entities MUST NOT use SCTP multihoming.
NOTE: The SCTPoDTLS mechanism does not support SCTP multihoming.
TBD
TBD
[RFC EDITOR NOTE: Please replace RFC-XXXX with the RFC number of this document.]
TBD
[RFC EDITOR NOTE: Please remove this section when publishing]
Changes from draft-holmberg-clue-datachannel-00
| [RFC3758] | Stewart, R., Ramalho, M., Xie, Q., Tuexen, M. and P. Conrad, "Stream Control Transmission Protocol (SCTP) Partial Reliability Extension", RFC 3758, May 2004. |