A performance model of deflection routing in multibuffer networks with nonuniform traffic

Deflection routing can be used in networks whose stations have the same number of input and output links. Fixed length packets arrive synchronously on the station´s input links at the beginning of time slots, and each packet is routed via the output link that offers the shortest path to its destination. Since the number of packet buffers at each output link is finite, the simultaneous contention of two packets for the last buffer of a common output link must be resolved by “deflecting” one of the packets to another output link. Thus, the deflection of a packet could result in the packet following a route that is not a shortest path. The potentially unbounded number of routes that a given packet can take makes analyzing the performance of such networks difficult. In particular, there are no analytical models that can analyze multibuffer deflection-routing networks with nonuniform traffic. Using independence assumptions, the authors develop a performance model of deflection routing that allows to estimate accurately and efficiently the mean transport time and throughput in a network that has any given two-connected topology, multiple buffers at each output port, and an arbitrary traffic matrix