I think it related to the card because we used a software to make calls of different people.
When it call via SIP trunk, it can %100 detect the other side answering, not answering, and rejection.
when it call internal extenision, it also can %100 detect the other side answering, not answering, and rejection.
However when it call landline via your OpenVox A400E card, No way to know wither the call is answered or not or reject!! it only can detect the DTMF keypressing only.
Did this ever get resolved? I'm having the same issue after putting the 400p in to a new system. I used to work fine.
Incoming calls to PSTN work 100%
Outgoing calls to PSTN do not detect far end answer. Multiple versions of Dahdi tested. Config is EXACTLY the same as previous which worked fine. Location is UK