Not as simple as it sounds because we need to determine the IP address of the callee
One idea of how to do that: use the Push mechanism of Android (the one used for Push notifications) to wake the client app on the called device, and have the client send its IP address to the server at that moment
Not as simple as it sounds because we need to determine the IP address of the callee
One idea of how to do that: use the Push mechanism of Android (the one used for Push notifications) to wake the client app on the called device, and have the client send its IP address to the server at that moment