Access and internal network protocols for providing switched multi-megabit data service

The authors describe the protocols that govern communications across two of the key interfaces to an MSS (metropolitan area network switching system): the subscriber-network interface and the inter-MSS interface. The SMDS (switched multimegabit data service) subscriber-network interface is based on an electrical DS3 interface in order to foster the early availability of network and customer premises equipment for supporting SMDS. The use of dedicated DS3 paths for customer access provides flexibility in terms of the physical placement of MSS equipment. A dedicated path affords the customer a degree of privacy and facilitates source address validation by the network. The simplicity and the connectionless mode of operation of the SMDS interface protocol will allow it to be easily integrated into existing, high-speed communications architectures. The inter-MSS interface and associated internal protocols facilitate the heterogeneous implementation of a multiple-MSS carrier network capable of supporting SMDS