Design and analysis of buffered crossbars and banyans with cut-through switching

The design and approximation analyses of discrete-time buffered crossbar and banyans with cut-through switching are presented. The crossbar switches can contain: (1) input FIFO (first in, first out) queuing, (2) input bypass queuing where the FIFO discipline is relaxed, (3) a novel scheme called restricted output queuing where the number of simultaneous arrivals to an output queue is upper bounded, or (4) a novel combination of input FIFO and restricted output queuing. An analysis for the delay distribution of a packet leaving the network is presented. Restricted output queuing (or combined input and restricted output queuing) can rival the performance of pure output queuing, while requiring far less hardware