Richard Shockey writes: > I think the XCON folks were trying to be inclusive > in their charter development but frankly I don't think > its necessary. The IETF now has three SIP related WG's > operating well and producing good work and the scope > of the XCON proposal IMHO should be directed at SIP > specifically. Its a complex issue, there is a real > problem statement and a focused WG could tackle the > problem head on and deliver results. This was the > direction we took with SIPPING for the specific IM > problem and its what we need to do with SIP Conferencing. I think some clarification is in order. The SIP conferencing work has been well underway for quite some time now in the SIP and SIPPING working groups. It is essentially complete, and will be in WGLC momentarily. We don't need a SIP conferencing working group; SIP conferencing already has a home. That said, for a conferencing solution to be complete, there are certain things that are required -- such as floor control and membership permissions -- for which SIP is simply not appropriate. The raison d'être for XCON is precisely to do the part of conferencing that is not SIP. The relationship between the XCON protocols and SIP are far looser than would legitimately warrant the level of concern being expressed on this list. For example: to be able to talk about specific media streams in a conference, you need to be able to identify streams of media. XCON does so in terms of SDP, since that is the mechanism used by SIP to establish media streams. To examine what this means in the context of the charter's claim that the solutions developed in XCON will not preclude operation with other signaling protocols: if someone were to decide to apply XCON to some theoretical IP-based call control protocol that used PSTN TDM trunks for conveying media [1], these identifiers could be replaced with SS7 circuit identification codes. If the initial proposals being presented as input to XCON had some strong binding to SIP that made their use in other contexts difficult, I would understand the concerns being expressed in this forum. However, the proposed solutions (all of which I expect to instantly be accepted as working group items in the case that the working group is chartered) demonstrate no such binding. I invite those with concerns to carefully examine the protocol proposals [2] and indicate where they believe this not to be the case. /a [1] This theoretical protocol is intentionally fantastic to avoid the discussion being bogged down with descriptions of any political reasons why certain protocol communities may elect to use different conferencing solutions. [2] http://www.softarmor.com/xcon/drafts/