Abstract: A hierarchy of multipath networks selectively provides connections between a plurality of sources and a plurality of destinations in a communications system. The hierarchy comprises a first multipath network without buffering which consists of two or more stages and constituting a fast path for connecting a source to a destination. At least a second multipath network with buffering and comprising a plurality of stages constitutes an alternate, slower path for connecting a source to a destination in the event that a connection between the source and the destination is blocked in the fast path. The address field of a message from a source is examined at each stage to select an appropriate connection to the next stage and, if the connection is available, the message, stripped of the address field, is propagated to the second stage, but if the next stage is blocked, the message is stopped and a negative acknowledgment is returned to the source.