Hi all I have this strange behaviour on my 3cx system. Can figure out if it is related to the client or server. On the machine that I installed 3cx server, it's a vanilla W2k3 machine with firewall turned off. I've setup a voip provider and receiving call OK. However, when I try to do an internal call, both sides only hears statics, no audio, no voice. can anyone provide some idea how should I troubleshoot problem like this one? thanks.