I just recently rolled out voip and the problem that I’m having is that when I call from an IP phone to a pbx phone or vice versa there is no dtmf tones or audio passing through. If a call is initiated on IP phones to IP phones dtmf exists. Cisco had already looked at my config and they are saying that it’s a problem on the pbx side. our PBX people are also saying that it’s a configuration on the Cisco side.
Hello goose, I am not sure if you are still experiencing a problem with this. You might want to make sure you have the “dtmf-relay” command under the appropriate dial peer that is pointing to your PBX. As a simple test, if you have FXS ports on your Cisco gateway, hook up a regular analog phone to it, run debugs or other tests to check if DTMF is being passed. If yes, then the problem is on your PBX side. If not, then focus on the Cisco gateway and try a different IOS version.