Hi Mike,
I am new to this forum, i may be wrong, the following is my offering:
From a carrier/operator point of view , we need standard body addressing the end-to-end QoS problems, Echo issues....
We need specs/standards to discuss with other carrier/operator....right now.
So much debate between SIP and H.323 but no real progress on this subject end-to-end QoS.
As far as i know to date , H.323 is probably in front in many aspects.  Why not going beyond the call.

Best Regards

James Dam
+61 29342 8195
James.Dam@cwo.com.au