Banyan networks for partitioning multiprocessor systems

This paper describes a class of partitioning networks, called banyans, whose cost function grows more slowly than that of the crossbar and whose fan-out requirements are independent of network size. Such networks can economically partition the resources of large modular systems into a wide variety of subsystems. Any possible partition can be realized by paralleling several networks or by multiplexing a single network in a manner to be described later. Results will be given indicating that a cost/performance advantage over the crossbar can be obtained for large systems and that the crossbar can, in fact, be considered a non-optimal special case of a banyan network. Inherent fail-soft capability and the existence of rapid control algorithms which can be largely performed by distributed logic within the network are also important attributes of banyans. This paper presents fundamental properties and preliminary simulation results of banyan partitioning networks. A more detailed treatment, including proofs of theoretical properties, is reserved for reference (5).