A fail-safe distributed local network for data communication*

We are concerned here with the design of an interconnection network for communication between terminals and computers in local distributed computer systems. By a local system, we mean one in which computers and terminals are concentrated in a relatively small area (e.g., with distance between terminals < 100 Km) and interconnected by communication links with relatively large bandwidth (e.g., up to 10 Mb/sec.). By a distributed network, we mean one in which the control of communication network is distributed among the computers and terminals. For our discussions, there is no need to distinguish terminals from computers. Hereafter, we shall refer to them simply as stations.