Hi Folks, i'm kind of new to 3CX (but large knowledge of VoIP and Sip trunking) we have the 3CX server running on server 2008R2. We register the phones to the 3CX server. And get the sip trunks from Asterisk (1.6) We use the asterisk (1.6) as an Sip provider/gateway for inbound and outbound calls. Everything seems to work fine, but there is one thing that not working at all. When i call the number, answer the call with the 3CX softphone and after X seconds i hangup the call from the Softphone. My mobile phone will not disconnect te call, it keep connected to the call. i do this from a External location. vice versa i hang up the call from my mobile it works just fine. When i do this internal on the server, everthing works. Normally you would say, that must be a firewall. But it's not, i opent all ports to the 3CX server on the firewall and still the problem exist. We are not using NAT. Does someone has any idea?