1) IP 1.1.1.1 refers to external networks, the subscriber must allow external connection. In his Options tab - see Disallow use of extension outside the LAN
2) Check in 3CX - settings-network settings - whether the internal address range and external address (1.1.1.1) are selected correctly
3) In the tab Phone Provisioning - look at the settings for the subscriber's application, what is it with the settings of Provisioning Method in the section IP Phone.
4) If the application works well and calls - then all the settings are correct, it just uses its own 3CXTunnel.
2) Check in 3CX - settings-network settings - whether the internal address range and external address (1.1.1.1) are selected correctly
3) In the tab Phone Provisioning - look at the settings for the subscriber's application, what is it with the settings of Provisioning Method in the section IP Phone.
4) If the application works well and calls - then all the settings are correct, it just uses its own 3CXTunnel.