We are experiencing an odd problem with 1 way audio in about %6-%8 of our calls.

It seems to me that what is happening is that our kamailio installation (using rtpengine) is some times ignoring the c= attribute that the carrier is sending us, and sending our audio instead to either address in the carriers o= attribute, or just to the same address we sent our sip invite too.

We have looked at hundreds of calls and haven't found a reliable pattern why this happens some times and not others. It really happens in a lot of different scenarios with lots of different carriers and differently formatted SDP packets.

I was wondering if any one had an idea where to start for a solution, or a way to make rtpengine always send audio to the ip in the c= attribute we are receiving from the carrier.

I haven't been able to find anything so far.

Thank you much for any assistance.

All the best.

Will