WG Review: SIP-TO-XMPP (stox)

A new IETF working group has been proposed in the Real-time Applications
and Infrastructure Area. The IESG has not made any determination yet. The
following draft charter was submitted, and is provided for informational
purposes only. Please send your comments to the IESG mailing list (iesg
at ietf.org) by 2013-06-10.

SIP-TO-XMPP (stox)
------------------------------------------------
Current Status: Proposed WG

Chairs:
  Markus Isomaki <markus.isomaki@nokia.com>
  Yana Stamcheva <yana@jitsi.org>

Assigned Area Director:
  Gonzalo Camarillo <gonzalo.camarillo@ericsson.com>

Mailing list
  Address: stox@ietf.org
  To Subscribe: https://www.ietf.org/mailman/listinfo/stox
  Archive: http://www.ietf.org/mail-archive/web/stox/

Charter:

Problem Statement

The IETF has defined two signalling technologies that can be used
for multimedia session negotiation, instant messaging, presence,
file transfer, capabilities discovery, notifications, and other types 
of real-time functionality:

o  The Session Initiation Protocol (SIP), along with various SIP
   extensions developed within the SIP for Instant Messaging and
   Presence Leveraging Extensions (SIMPLE) Working Group.

o  The Extensible Messaging and Presence Protocol (XMPP), along
   with various XMPP extensions developed by the IETF as well as by
   the XMPP Standards Foundation.

SIP has been focused primarily on media session negotiation (e.g., audio
and video), whereas XMPP has been focused primarily on messaging and
presence.  As a result, the technologies are mostly complementary.
However, there is also some overlap between SIP and XMPP, since there
are SIP extensions for messaging, presence, groupchat, file transfer,
etc., and there are XMPP extensions for multimedia session negotiation.
This overlap has practical implications, since some deployed services
use SIP for both media and messaging/presence, whereas other deployed
services use XMPP for both messaging/presence and media.  When such 
services wish to exchange information, they often need to translate 
their native protocol (either SIP or XMPP) to the other protocol (either 
XMPP or SIP).

Implementers needing to perform such protocol mappings have often worked
out their own heuristics for doing so.  Unfortunately, these heuristics
are not always consistent, which can lead to interoperability problems.

Objectives

To make it easier for implementers to enable interworking between
SIP-based systems and XMPP-based systems, several Internet-Drafts have
defined guidelines for protocol mapping between SIP and XMPP, starting
with draft-saintandre-xmpp-simple-00 in early 2004.  The current
documents are:

draft-saintandre-sip-xmpp-core
draft-saintandre-sip-xmpp-presence
draft-saintandre-sip-xmpp-im
draft-saintandre-sip-xmpp-chat
draft-saintandre-sip-xmpp-groupchat
draft-saintandre-sip-xmpp-media

These documents are fairly stable and the authors have received feedback
from a number of implementers over the years.  However, implementers do
not always know about these documents because they are Internet-Drafts
and sometimes they have become expired due to inactivity.  Thus it would 
be helpful to polish them off and publish them as RFCs.

It might also be helpful to at some point publish additional documents in

the same series, covering topics like capabilities discovery and file 
transfer.  However, any such work would require a recharter.

The group shall not be tasked with defining any new protocols, only with
specifying mappings between existing protocols that have been defined for
SIP and XMPP.

Deliverables

1. Address mapping and error handling
2. Presence mapping
3. Mapping for single instant messages
4. Mapping for one-to-one text chat sessions
5. Mapping for multi-user text chat sessions
6. Mapping for media signaling

All of the foregoing deliverables are standards track, since they are
subject to interoperability testing.

Milestones:
TBD