An open Services architecture for inter working narrow band services with equivalent broad band services delivers services on both the existing narrow band network and a future broad band network based on flexible signalling connections. The architecture incorporates an adaptive grooming router providing a fully interconnected backbone network function providing connectivity between a plurality of multimedia access routers and a narrow band network. The multimedia access routers provide hub points where access units terminating ISDN basic access and primary rate access lines used for multimedia services are terminated.