Our CallManager is using a gateway configured with 2 T1s. The T1s are in NFAS configuration, 1 Primary D channel and the other is a Backup D channel. In total, we have 46 B channels available for PSTN calls.
If I run "sh voice call stat", it shows me the correct number of Active ISDN calls. If I run "sh isdn serv", it shows that calls are spread between the 2 T1s (so NFAS configuration is working). If I run "sh isdn nfas group 1", it shows the correct number of available B channels (46 minus number of Active Calls).
In CallManager, Route List is configured to use PSTN Route Group and if all channels are used, it will failover to using VOIP (Gatekeeper).
Problem is eventhough we have 46 B channels, we can only make 23 simultaneous ISDN calls, the 24th call uses VOIP. We're supposed to have 46 calls but it seems CallManager is recognizing the NFAS as 1 T1.
Any ideas? Thanks.