I have a customer that is using voip between sites, currently they have traditional pbx conected to 2800 routers via isdn with qsig with hdlc encapsulation. They have a gatekeeper in the main office and 15 branches.
Now I put an cucm6 in a new branch off. and create an h225 trunk gatekeeper controlled between the cucm and the gatekeeper. One of the issues still Im working is the ring back tone. When the users in the main office (@ gatekeeper side) with traditional phones dial to ip phones (@ branch), they don't hear the ring back tone. I change some h225 ent. parameter without success..