Google Voice -> Asterisk disconnects in directory


This is a heads-up for all your VoIP nerds out there (like me!) hehehehehe

I finished an Asterisk installation about two weeks ago. The client started calling a few days ago complaining that every time an external caller accessed the Directory it would disconnect when pressing 1. So… for illustration…

CALL CallCentric provided DID -> PROVIDER -> Asterisk -> IVR -> 9 for Directory -> 6(M) - 4(I) - 5(K) -> "This is the person you are trying to reach? 1 for yes… " -> 1 -> CALL DISCONNECTS

I call to the CallCentric provided DID, spend about 2 hours trying to reproduce the problem but no luck. I call the client and we debate the issue. I SSH into the box, fire up the Asterisk console, turn up debugging as high as it will go, get on 3 way and he can reproduce the problem. I ask him, “What number are you dialing” and he responds with a non-CallCentric DID. When I tell him that is not the number I am calling he explains they are using Google Voice.

After a couple more hours of troubleshooting we finally found the problem. It appears there is a glitch with Google Voice. If either the person making the call OR the person answering the call generates 5 DTMF tones within a reasonable amount of time then the person generating the DTMF tones will be disconnected from the call BUT the call does not end.

I thought I would pass this along because I suspect Google Voice is going to gain in popularity when they start offering number portability. This means alot of people will be arbitrarily disconnected when using Asterisk dial-by-name.