once the call has been sent to Unity, we look up the forwarding number of the incoming call and look for it on the local Unity server - if no match is made it sends the call (by default) to the opening greeting. there's no provision to search other Unity server's in the site for a match on that forwarding number and to "hand off" the call to that Unity box.
there is cross box login (i.e. if you call into any of the Unity servers and go to sign in Unity can be setup th "hand you off" to your home Unity box) and cross box transfer (from the auto attendant if you dial the number of a user on another box it can be "handed off" to that Unity server to handle) but if the call forwards into Unity from a number it will be handled by that box.
