Softswitch for the next generation network (NGN)

Softswitch is the concept of separating the network hardware from network software and it combines the reliability of PSTN and the flexibility of IP appropriately. The main idea of softswitch is the de-coupling the service, control, transport and access. Each entity interconnects and communicates according to the standard protocols. This paper provides not only the conception, technology features, the network architecture and each layer's function of softswitch but also the connections and differences between softswitch and next generation network (NGN). This paper introduces the Lucent softswitch and summarizes the achievements as well as problems both domestically and internationally.