I have a customer that is using Elastix 1.6 and Aastra 6730i phones along with XML. Earlier in the year they had an audio problem where in the middle of a call they lose audio from the receiving side not the customers and have to tell the customers to hold on it will come right back after 20 secs. After that the call comes back and its fine for a while. I ran an rtp debug and also had the customer tell me the exact times of the occurences, I can see the sent and got packets going fine until it happens and I see they can only send for an amount of time then back to send and got back and forth. Common sense tells me sending only is one way audio from the client to the customer. Ok so I see the problem, I just dont know what to change to fix it. This went a way before when I separated the networks and replaced the brighthouse modem. It came back when I installed and configured the xml scripts and rebooted everything. I always spend at least half an hour researching this on here and google and without tears before posting. Look forward to your replies. Hopefully it is something I can change in RTP.conf that will make this work.