We are having a strange issue that we can't seem to track down and I was hoping someone could help point us in the right direction. Previously we were using a 3725 ISR integrated with our Hicom 300 and calls between the two were working fine, but lacked caller ID. This is a feature we wanted to give to our users moving forward with our migration (slow) to Cisco VoIP. We replaced our 3725 that had failing hardware with a new 2951 and had to convert the T1 integration to a PRI (QSIG). So, we copied what we had in our previous config and made the necessary adjustments for the PRI. At one point we thought that we had everything working including caller ID from PBX to VoIP extensions and VoIP to PBX extensions.
As it stands now, we cannot make 4-digit calls from PBX to VoIP extensions. 4-digit dialing from VoIP to PBX works perfectly fine. The strange thing is that if we call from a cell phone or dial out of the PBX by using 8+7-digit DID number from a PBX extension, calls get delivered to the correct VoIP phone. It seems that when we call the 4-digit VoIP extension that it just wants to come right back over the PRI to the PBX again and eventually after a long period of time, it times out. We having been looking heavily at the dial peers, but this config used to work on the old ISR, so I don't know that this is the issue.
Here is our current setup and integration:
PSTN <<==>> Hicom 300 9006.6 (PBX) <<== (PRI-QSIG) ==>> 2951 ISR (Gateway) <<== (H.323 Gateway) ==>> CUCM 7.1.3
If someone could point us in the right direction, as far as troubleshooting is concerned, that would be fantastic. If you need additional information and I'm sure you will, please let me know. Thanks for your help.