1. A method of managing connections in a mobile communications network, the method comprising: transmitting over a connection from a network entity to a mobile device natural traffic and keepalive messages at a frequency determined by at least one keepalive parameter; at the mobile device, monitoring receipt of the natural traffic and the keepalive messages, and closing the connection upon detection of inadequate natural traffic and missing keepalive messages; and dynamically adjusting the at least one keepalive parameter for subsequent transmission of the keepalive messages from the network entity so as to maintain the connection at a minimum frequency of keepalive messages.