Incoming Calling Rules and h323 Trunk?

Hello All,
I am completing an install of Asterisk 1.6.Current with ooh323 connected to an Avaya. All works on incoming calls from Avaya to the extensions. However, on outbound calling I get:

[Oct 14 15:05:53] NOTICE[2989]: chan_sip.c:18523 handle_request_invite: Call from ‘2182’ to extension ‘94045551234’ rejected because extension not found.

I will probably figure this one out on my own but it got me thinking on how to handle inbound calling from the Avaya. I would like to set up an inbound calling rule but I need to have a trunk set up first. Since I am only using h323 I don’t see how I can do this. Am I stuck using the .conf files to direct any special inbound routes?

Any thoughts or ideas?

I appreciate any ideas…

I guess I should update this and state that I am referring to Incoming Calling Rules within the GUI 2.0…