1. A network of multiprocessor systems, including: a plurality of multiprocessor systems, each of said systems containing at least one processor connected to an interprocessor bus, a plurality of node interfaces, each connected to a respective one of said interprocessor busses, each of said node interfaces having at least one data link connecting it to at least one other node interface such that all of said node interfaces are characterized by the property of global connectivity, a buffer memory in each of said node interfaces, having a plurality of storage locations for temporarily storing message packets to be transferred to any one of said processors in said network, said storage locations being partitioned into groups of storage locations, each one of said groups corresponding to a particular one of said processors in the network which is the destination processor for all of said message packets placed at locations therein, control means in each of said node interfaces for controlling the transfer of said message packets into the buffer memory in its respective node interface from the data link connecting the respective interface node to its adjacent neighbor interface nodes and from the interprocessor bus connected to the respective interface node, and for controlling the transfer of said message packets out of the buffer memory in the respective node interface to the data link connecting the respective interface node to its adjacent neighbor interface nodes and to the interprocessor bus connected to the respective interface node, means, in each of said control means, for determining how many of the storage locations in a group of storage locations (in the buffer memory in its node interface) corresponding to a particular destination processor are full.