The role of MANs, cross-connects and virtual paths in the evolution to broadband ISDN

The author examines the role of some key technologies as networks evolve to the broadband integrated services digital network (B-ISDN). From the ISDN, the development of metropolitan area networks (MANs) to support high-speed data services such as LAN (local area network) interconnection is described. MAN subnetworks can be interconnected by reconfigurable networks of cross-connects. Both synchronous digital hierarchy (SDH) and asynchronous transfer mode (ATM) cross-connects are expected to be available prior to B-ISDN. Networks of ATM cross-connects rely on the virtual path to identify and manage flows of traffic. The role of virtual paths in reducing the complexity of call control processes in the B-ISDN is also assessed