We currently have a non-gatekeeper controlled ICT between 2 campuses. One is running 5.1 and the other is on 7.1 - the ICT trunk is working perfect. The problem is that we do not have a failover to go out the PSTN when the WAN is down.
Cluster A dials #2XXXX (strips the #2 off and sends 4 digits). Cluster B dials #1XXXXX (strips off the #1 and sends 5 digits).
Both locations have an entire block of PSTN DIDs - the last 4 or 5 digits match the DN.
Configure 2 route groups, 1 with ICT, 1 with PSTN GW
Assign them to a route list, ICT then PSTN
Configure the necessary transformations under route list config for the PSTN option to prefix the calls with the necessary digits to route them
if this helps, please rate