It's not an impossible task, but one that may lead to tremendous debate. It is quite obvious that some members of the ITU and some members of the IETF have very basic philosophical differences. I can tell you that some members of the IETF will quickly reject anything the ITU does to standardize interoperability. I can also tell you that some of those members will also reject anything ETSI does, as well.
Paul, I'm going to flame you, so dont take it personally.
Paul, please! Such an argumentation coming from the ITU-T worries me quite a bit!
Couldn't you think that this may actually have something to do with the fact that 3-4 years of interoperability trials for H.323 in Etsi/ITU/IMTC have lead to an amount of interoperability that was acheived in 1 or 2 bake-offs for SIP. That going to a SIP backeoff is cheap and attending the ITU-T is outrageously expensive. You can try to depict otherwize, but the basics underlying reasons why the ITU-T is doomed to perpetuously deceive IETF participants are still there ... no rough concencus, no running code, membership fees which lock-out small players, closed-policy on publication of standards, closed mailing lists, shall I go on ?
The interest in interoperability with SIP is presently a one way relationship which comes from the H.323 people. Thus, it is the same H.323 people whi should consider coming to an industry-open, SIP bake-off. You can try talking Henning Schulzrinne into lettin you in. I'm sorry, but we just dont need the ITU-T, ETSI nor the IMTC slowing us down at the IETF ;-)
I think that all of your analysis is rubbish. You could simply bring your stuff at one of the SIP bake-offs and get the feedback you need to go on and experiment a little more with H.323 ... You can try all you want to turn a Gatekeeper into a Proxy server/Redirect server, but it'll probably not happen in the marketplace.
This said, I'm sorry for flaming you.
-=Francois=-, "the guy who still cares about doing the dirty work when its necessary."