Hello. I'm facing a problem i don't understand. 1st i am able to call / and receive call , on the same computer using - 3CX VoIP Phone , configured to use the SIP account of my SIP. So what's the problem then ? I'm playing with the 3CX Phone system (free edition , registered). - I configured 3 extensions for 3 different computers on my Lan. - i configured a VOIP provider with my SIP account. I can see in the log that it registers. - i can call one extension from another - i can call outside (my cellular) from my extention : Cellular rings. but when i take the call : NO SOUND , in both the cellular and the extention ..... - i can call my SIP phone number and make all extension ring at the same time (using group). If i take the call : NO SOUND ! any idea of what's going wrong ? I checked the firewall using the dedicated menu . Everything is "checked passed".