I have two clients that I manage to connect to the PBX-server.
We have five SIP-numbers. When I call the server number from another SIP number, the line is busy. When I call the same number from my cellular, then the woman speak, “the number is not available”.
There should be a “connected user viewer” somewhere (similar) to see the connected clients. Or simply a viewer… (Windows laptop, MicroSIP + iPhone, Zoiper.)