I have a 7200 with a mp20s and a PRI. All calls, inbound or out drop after 15 minutes on the dot. Any ideas on what I should look for to help solve this? We've had the provider check the circuit, and look at the calls that dropped, and they don't see it as a drop. They see it as a clean disconnect.

Looking at the system, I do see there is no system license installed on the 7200 and the Demo license is not enabled. Would this limit calls in and out of the system?