Settings are the same, 100 and 500. If you aren't seeing any errors on the system, and the PRI settings are typical, and all else at default, then should work, but then you knew that, huh?
Point the finger of doubt at Telco, and request them to send a tech with a T-Bird or other equipment, and prove that it works.
Possible that equipment is goofed, but not likely here. Even if not Telco, they should be able to provide you with what they see when a call comes in or out, and give you feedback if it is your equipment.
Pepperz@charter.net