The role of SONET-based networks in British Telecom

The introduction of SONET (synchronous optical network) digital networks into the British Telecom (BT) transmission network is discussed. The flexibility thus achieved will be used for functions such as traffic grooming (e.g. to maximize fill factors) and to implement an integrated protection strategy, whereby spare transmission capacity is managed by downloading protection algorithms to meet the local requirements of each region or network layer. New network topologies will facilitate ease of growth, good path availability (including dual access), and resilience against disasters. These topologies will make maximum use of the existing duct routes. It is concluded that, when combined with new network architectures and management philosophy, SONET-based networks will allow BT to provide improved quality of service and the ability to meet customer requirements into the future