Optimizing quality of service in packet switch scheduling

Recently, extensive analytic research into packet scheduling in crossbar switches has yielded interesting throughput maximizing algorithms. Surprisingly, however, quality of service (QoS) performance associated with these algorithms has only been approximated through simulation. We present here certain randomized algorithms with analytic QoS. These are simple to implement and possess closed form expressions for various performance measures. By fine tuning particular parameters of these algorithms, one can vary the QoS associated with the individual ports as desired. This allows cost and utility optimization, a feature which was not feasible under previously studied packet scheduling algorithms.