Issue:
When I make a call using a non-pbx device (my cell phone in this case), I can answer the call and spend as much time on the phone as I want. If I don’t answer the call and allow it to go to voicemail, I don’t here any prompts at all, not even the system prompts. The PBX doesn’t record anything, and I get a zero length message at the extension. If I call the same extension from another extension, I hear my unavail message and all system prompts, and can leave a message, that gets recorded properly.
When placing the external call, I hear my IVR message just fine and all the system prompts up to the point where I should hear voicemail prompts.
In continuing my troubleshooting, I’ve found that if I turn DND on, the external call goes to voicemail just fine and the user can leave messages. I’ve submitted a ticket to my VOIP Trunk provider to see if they have a timeout set on the trunks that disconnects the call just before the voicemail can accept it. If anyone has any other ideas I’d appreciate the help.
So, in continuing my troubleshooting, I’ve now discovered that if I have two lines registered (i’m in device and user mode) as different devices, but the same user, and I hit ignore on both devices the caller is directed to the voicemail properly. If I hit ignore on one, and let the call ring on the other, it also goes to voicemail properly. If only one of the devices is on line, the problem described above occurs. If no devices are registered for a user, it also goes to voicemail properly.
The issue turned out to be that an update cause the SIP trunk provider’s Peer Details to need an additional parameter, but they didn’t notify us about the new requirement.