MULTI-LAYERED ARCHITECTURES FOR COMMUNICATIONS NETWORKS

A layered architecture for a communication network comprises a first layer forming a transport network and a second layer forming a service network. The transport network provides bandwidth management, high capacity and physical layer survivability, and the service network provides switching and routing of the traffic, service layer survivability and other user oriented services. Combination of various technologies such as ATM, or IP over SONET/SDH are considered. A node of such layered networks comprises physically separated transport and service network elements (NE) interfaced to each-other.