Hi Straker
i prefer to remain in the international forum to have (and give ) maximum support .
In attach you can find a simple demo project .
I have set up a listening server , i tried under H3G network and after the connection there isn't Exchange of byte , otherwise under wifi i receive data from server.
After the connection , the server send every 2 second the actual date and time , and wait for a keepAlive message from mobile device, after 6 seconds without this keep Alive message , the server close the connection and restart to listening .
The Mobile App after the connection, shows on a label the arrived message and send every 1 second a keepAlive message .
If the mobile App doesn't receive any message from server for 6 seconds , closes the connection and retry to connect