I'm working my way into learning VOIP, but I have a problem that needs fast resolution and I need some recommendations on where to begin.

Users in a city are complaining of several issues with caller ID, all the calls are calls originating from my site to an external location:

Location 1 has an issue where the caller ID shows up as unknown.

Location 2 is getting "random" numbers, none that belong to that facility when they call out.

Location 3 is having a random number no even assigned to my DID being sent out.

Location 4 is just sending out the wrong number.

Configuration of the numbers is coded on the route list and is correct.

I have a T1 that these sites all share as well as some POTS lines. T1 is preferred for 2 of the 4 sites, the other 2 are pointed to 2 POTS lines then the PRI (don't ask me why, this will be changed soon and could be part of the issue).

When I make test calls remotely from my office, I see the debug spit out the proper DID but I get the "main" number to pop up on the caller ID. When I visited the site, I had users call my cell phone while I was there and sure enough saw their problem.

I need a place to start looking, if someone could verify with me the hierarchical flow for caller ID (phone, device pool, gateway, route group, route list etc.) and preference (a hard coded number set on the route list overrides the gateway etc.), and tell me where you can hard set these DID's I can definately find it. And any other help is definately appreciated, everything I know about this system I learned today.

Thanks,

Craig