Chris,
You wrote
Consider the case of a v1 gatekeeper routing H.225.0 and NOT H.245 in a call between two v2 endpoints.
and in your mail about SUDs you say
Incidentally, you are mandating gatekeepers to route H.225.0 AND H.245 messaging (not many do the latter yet!)
I don't know what you're drawing on for this, the Gatekeepers I know about route both. Both H.323 version 1 and version 2 state that
When Gatekeeper Routed call signalling is used, there are two methods to route the H.245 Control Channel. In the first method, the H.245 Control Channel is established directly between the endpoints. See Figure 11. This method is for further study. In the second method, the H.245 Control Channel is routed between the endpoints through the Gatekeeper.
This statement clearly indicates that until that study occurs, the scenario you are describing is not supported by the protocol, and may or may not work properly.
Regards,
Dave Walker Mitel Corporation Ontario, CANADA