Please disregard my previous posts. Apparently I solved the problem not by replacing the 5060 port but by adding the new port at the ser.cfg listen=10.0.1.99 port=5060 listen=10.0.1.99 port=8080 I setup the listening port and the SIP port on the Xlite to 8080 and is registering fine. ngrep is showing that the source port and the destination port both ways is 8080 so it should be working. I will test it in the real world and inform. Thanks and regards Juan