I'm having an issue where I'm unable to connect the 3CX phone from inside or outside the office using TCP. UDP works just fine, but for some reason TCP stopped working a few days ago. At first I thought it was a firewall issue, but I even tried from a 3CX phone in the office and it still wont register. No firewall or AV software is running on the PBX. The reason I want to use TCP is that's the only way I can get the outside phones to receive incoming calls without using the tunnel. The tunnel is not an option for the iPhone.