BigPatents India

A method of, and apparatus for, communication of datagrams over a network comprising sub-networks (1 to 5) served by respective sub-network servers (7 to 11) from a sender terminal (15), especially a mobile terminal communicating over a wireless link, and a plurality of destination terminals (12 to 19) served by a plurality of said sub-networks (1 to 5), in which the datagrams are routed using destination identifications contained in the datagrams. A sub-network grouping server (20) selects a plurality of the sub-network servers (1,4) and provides communication of datagrams between the sender terminal (15) and destination terminals (12, 13, 16) within the corresponding selected sub-networks (1,4) the selection being made according to criteria, such as geographic position, chosen as a function of information derived from the sender terminal (15) without the individual destination identifications of the destination terminals (12 to 19) being specified by the sender terminal (15).