I have been having on-going issues with call audio dropping out (ticket #116905).

It *appears* that port numbers between our 2102 and WxC are being changed mid-call.

I have set up tcpdump in a bridge between the 2102 and our Telstra cable modem.

I need a bit of help deciphering what I see, which is esentially this.

my_ip:5075 > wxc_ip:5060
wcx_ip: 5060 > my_ip:5075

I do see the port numbers jump around after reseting the 2102 and they seem to settle on some port number. (This time 5075).

I just reset the 2102 again, while writing, and this time it has settled on 5060 both ways, then jumps to 60/75, 61/60, and has not settled on 60/62.

Telstra have said that they do not tamper with any traffic.

Anyone have any clues ?