Performance of Hypercube Routing Schemes With or Without Buffering

We consider two different hypercube routing schemes, which we call the simple and the priority schemes. We evaluate the throughput of both the unbuffered and the buffered version of these schemes for random multiple node-to-node communications. The results obtained are approximate, but very accurate as simulations indicate, and are given in particularly interesting forms. We find that little buffer space (between one and three packets per link) is necessary to achieve throughput close to that of the infinite buffer case. We also consider two deflection routing schemes, called the simple nonwasting deflection and the priority nonwasting deflection schemes. We evaluate their throughput using simulations, and compare it to that of the priority scheme.