When on local LAN WiFi I can make External calls. When external i.e. using 3G/4G data connection I can only dial internal numbers i.e. Operator extension on internal 3cx PBX not external calls. I have the presence working, not using the 3cx Tunnel (could not get that working at all). The 3cx client when external can re-provision without error. Ports 6001 and 5060 UDP/TCP are allowed through firewall. Have I missed something in config. Have uninstalled the 3cx client and re-installed.