I am working with a CUCM system that has approx. 30 end nodes. Each node has a VGW using MGCP and a PRI. I have a route group configured for each node with there PRI in the group. Then I have a route list that has each of the route groups in the list. Here's the problem. When a broadcast message (via IPCelerate's IPSession i.dialout) is initiated, the first call goes out of the first route group entry in the route list, as expected. Subsequent calls go out as expected as well, until the first route group PRI is full. Once we get to the point where there are no available ports on the first route group, I would expect that the second route group is engaged to continue making calls. This is not the behavior I have experience. Instead, I receive errors shown in the call log on IPSession with cause code (101, unknown). I have researched this error and it turns out this error means that there were not available channels to make the call.
Question: Once the first route group PRI fills, why does CUCM not fail over to the next route group to continue making calls?
From my current research, I find documentation that multiple PRI entries in a single route group will accomplish this, but nothing that deals with failover on the route lists themselves. Our original understanding of the route planning was to use the group to specify a node and then lists to create failover scenarios. The above does not act this way. Do I need to reconfigure my route plan to redefine failover in the route groups?