Abstract: A connectionless oriented communications network is disclosed having a plurality of IP network routers R1-R3 controllable by a service controller S the service controller S being arranged to set a service across the network by configuration of at least some of the routers R1-R3, configuration instructions to determine packet forwarding behaviour sent from the service controller S to the routers R1-R3 being in a common form and each router R1-R3 having associated therewith a translation program for translating the common form instructions into configuration information specific to that router.