Subject: RE: [Sipping] SIP & T.120

From: "Even, Roni" <[email-masked]>
Date: Thu, 4 Apr 2002 14:12:30 +0300

Sanjoy,
 
The issue of integrating SIP and T.120 was mentioned in draft-levin-sip-for
-video. the work is continued after the Minneapolis meeting by a group that
tries to define the requirements and framework for multimedia conferencing.
Using T.120 for control was discussed in the initial phases of H.323 and was
not accepted due to the complexity of T.120 as well as the low availability
of a stack. I would argue your point of wide deployment. It is true that
Netmeeting is a T.120 client but if you want a stack for an embedded
platform you have a problem. Databeam who used to be the major vendor of
such stack does not do it this days.
As for data collaboration there is no other protocol and I think that the
industry would welcome such a protocol. Today you can see web collaboration
applications but they do not have full application sharing capabilities.
Roni Even
Polycom

-----Original Message-----
From: Sanjoy Sen [mailto:[email-masked]]
Sent: Wednesday, April 03, 2002 9:52 PM
To: [email-masked]
Subject: [Sipping] SIP & T.120

Is there any ongoing work or planned work in the WG to integrate SIP and
T.120/whiteboarding ?  Is this the right place for this work or should this
be handled at MMUSIC?

The fundamental issues that come to mind : 
1) T.120 family does everything from capability negotiation (T.121), session
set-up (T.122), to conference control (T.124). Should we, for simplicity's
sake, use SIP just to set-up transport for T.120 and leave everything else
for T.120 to handle? This makes some sense given the wide deployment of
complete T.120 stacks. However, there're lot of overlap between the Generic
Conferencing Model (T.124) and SIP conferencing models and framework, and
their interactions need to be sorted out (e.g., Join). What're some of the
new SDP attributes that need to be defined?

2) The alternative is, of course, to recreate "whiteboarding" using SDP &
SIP conferencing models. Is anybody aware of any ongoing work in other
bodies (e.g., W3C)?

What is the general opinion of the WG on starting some work on this? 

Thanks, 

Sanjoy 
[email-masked]