Buffer length impact to crosspoint queued crossbar switch performance

Performance analysis of two crosspoint queued switches, with four and sixteen ports, is presented in this paper. Crosspoint queued switch architecture has been recently actualized, since it is now not a problem to implement large buffers in crosspoints using modern technology any more. An advantage of this type of solution is the absence of control communication between linecards and schedulers. Four algorithms are used to implement a scheduler: longest queue first, round-robin, frame based round robin matching and random. Throughput, average cell latency and loss probability, are evaluated under uniform and various nonuniform traffic patterns. Results will show that the longest queue first algorithm has the best performance in most simulated cases. It will also be shown that an implemented algorithm does not have any influence on switch performance if the buffers are long enough.