The invention provides for a method of communication within a mobile radio communications device between a chip-card in server mode and any one or more of a plurality of clients each having the same IP address, the method including the steps of creating for each of the clients a socket, wherein each socket is bound to a client port allocated by the device, associating a client identifier to each of the bound client ports, and making each said client identifier available to the chip-card whereby the chip card can distinguish between messages from the plurality of clients.