I have to provide a full 10-digit number or the output will be the default number of the circuit (I think SPID is the buzzword), and the same goes if the number is not a DID on that circuit. Even though I "own" 5600 numbers spread across 6 buildings served by the same CO, if I try to give out a number in one of my other buildings the outcome will be the default number of the circuit (which I have tried to have set to the main answer point of that building for that exact reason). AT&T is my carrier as well. These are traditional copper PRI. I have one new site that has BVOIP (which is basically a PRI card in the back of a 2900 router) and I had the fortune to be working with the person at the keyboard when it got set up, and he let me set the default number of the building there to a DNIT to a call center in a different building. So those phones can either give out a number in their building OR that one special number. Problem with that one is there is some kind of authentication required to make 800 calls on that circuit, and if I change the PUBNUM to anything other than the exact extension number then it will not allow them to dial 800 calls.... Sometimes yah can't win! Fortunately they don't realize the calls are failing as unauthorized because they get a standard busy signal, so they have been in that building close to 3 years and no one has complained about that yet!
Now I could also believe the PBX might have a role in that number restriction thing, but as far as the PBX knows that is one big system - all the shelves are running off the main location unless there is a link failure and then they can be islands, so I'm not sure how it would know those other 4 PRI circuits are in other buildings...
Don Bruechert, Voice Comm Analyst II
CareTech Solutions @ Holy Family Memorial
Manitowoc, WI, USA