Hello, I've installed the server and client, then disabled the firewall on both computers. An extension has been added also, 100. When I try to connect to the server from the client app using headphones, I get the AUtheication Failed. On the server it says bad credentials, so I haven't been able to register the extension yet. Here are the ports on the client that i'm using, sip=5060, first rtp=7000, last rtp=7499 and tapi=4300. Thanks for your help.