I have a two different VOIP gateway. I was able to call from gateway A and get two way voice conversation but calling from gateway only get one way voice. What seem to be the problem?
check the codecs. or if it isn’t the codecs it will be a RTP Port issue. i.e. upon connection message gateway A will connect on RTP port 3000 and gateway B will connect on RTP port 2000. This will result in one way audio.