The invention refers to a method for optimising the data communication in a network comprising a wireless radio network using connection oriented protocol (TCP) over internet protocol (IP). The network comprises a router (SGSN) intervening the connection oriented setup between a host (SERVER) and a client (MS), and changing the maximum segment size (MSS, ms) into a maximum segment size (MSS, sgsn) based on the router's (SGSN) knowledge about the radio network.