Effect of a Finite Reassembly Buffer on the Performance of Deflection Routing

Deflection routing is a distributed switching strategy used primarily in slotted regular networks. Since the deflection routing scheme forces packets to take multiple paths to the destination, the packets may arrive out of sequence and this necessitates the use of a reassembly buffer at the receiver end. In this paper, we propose to study the effect of a finite reassembly buffer on the performance of deflection routing under a specific non-uniform traffic model. We develop an analytic model to understand the effect of oversubscription to links on the probability of packet loss at the reassembly buffer and the effective throughput as seen by the source. The effect of adding output buffers at the nodes on these performance measures is also investigated. We shall also study the performance of deflection routing in networks of different sizes like local, metropolitan and wide area networks.