I have a dahdi channel set up for my T1 trunk and have incoming calls terminate on the demo context for now. The issue I am having is that when the call is answered, it is muted to one way audio. I had this terminate to a SIP device where someone was answering and we were noticing that the SIP device could hear the PSTN caller, but not the other way around. I changed it to the demo context to continue testing without bothering the other person, especially since the audio not being heard was from PBX to the PSTN.
The weirdest thing is that if the PSTN side caller were to press a key on the keypad (ie. DTMF, also made no difference to which key I pressed) then the audio would be available again on both ends till the end of the call. I have spent hours trying to find out why that may be the case, but to no avail. It is always the case that there the PSTN can’t hear the PBX audio until the DTMF is pressed.
I checked the dahdi_monitor visualizer and I see the audio being transmitted, but still no audio on the PSTN side. After increasing the “core set debug” to 100 I still saw no log entries that would show me what was being changed by pressing the DTMF key. This afternoon, just by chance, I saw that while doing “dahdi show channel 1” I was seeing that the line “Actual Confmute: Yes” gets changed to “Actual Confmute: No” after I press the DTMF. When the channel is active, the setting there is No, but changes to Yes when the call is answered, and after the DTMF goes back to No when there is audio going through.
My question is, (a) how do I turn off Confmute permanently? (b) What is Confmute? Is is the conference bridge muting? © Can i turn it off on a per call basis from the dialplan, once the call is answered?
I have no audio where I can change that setting, so your help is much appreciated!