1. A method for IP [=Internet Protocol] communication between a mobile terminal and its correspondent node in a mobile radio network, the method comprising: establishing an IP connection between the mobile terminal and its correspondent node; in response to detecting a period of inactivity in the IP connection, sending keep-alive messages via the IP connection at predetermined intervals; varying the predetermined intervals and monitoring the lengths of several periods of inactivity at which the mobile radio network disconnects the IP connection; based on the several monitored lengths of periods of inactivity, determining a maximum interval between keep-alive messages such that the maximum interval meets a predetermined criterion of statistical confidence; and setting the interval between keep-alive messages to the maximum interval.