I have searched this issue several times and although there are plenty of topics on this issue, the many I have looked at do not seem to match my topology or setup exactly and the fixes don’t work on mine.
Here is my topology:
Google Voice ------ Router ----- PBX (PIAF) ----- CUCM -----IP Phones
Currently I can call out using the IP phones to an external cell phone just fine, but incoming the ip phone rings and I pick up, but the external phone continues to ring and ring.
I am using the Google Voice Module that was added in and seems to be working. I have opened ports 5060 & 10000-20000 and pointed them to the PBX (which I don’t if this needs to be CUCM). This is my SIP trunk configuration:
Please let me know if there is anymore information you need!