How do you configure MGCP to support a fractional PRI? It keeps changing the pri-group on the controller to all 24 channels.
Cisco DO NOT support the use of MGCP with fractional E1's. This said, there is an UNSUPPORT work around which allows you to specify in call manager which channels are available, see below: -
Within the advanced CallManager service parameters (not shown by default) there is a field called "Change B-Channel Maintenance Status 1" which can be altered to mark channels out of service. The string below will need altering depending on how many channels are in use (0 = available, 1 = unavailable). The string below is an example for 20 channels.
Change B-Channel Maintenance Status 1 as follows:
[email protected] = 0000 0000 0000 0000 0000 0111 1111 1111