I am doing a final year project and i will make a peer to peer mobile application, but at first, as an example, I am planning to do an application like classic "ping-pong". I have no experience on mobile connections, so maybe my question is strange. In ping pong application, one of the phones will be server and the other one will be client, i will use sockets, so i need a normal socket connection and a server socket connection. And my client phone will connect to server phone and send "ping" message , after that my server phone reply to my client with "pong" message. But i need ip address of my server phone so how can i reach the ip of my server phone, or else how can i connect my server? In forums i have read that its impossible, because providers dont let it. If you have an idea please share.... Thank you !