Matching Algorithm with Queue Length Weighted Service for Input Queued Switches

Input queued switching architecture has attracted more attention.Due to its good scalability,it has become predominant in high performance switches and routers.In this paper,the concept of matching with queue length weighted service(MQWS) is presented to handle the scheduling problem for input queued switches.In the scheme the matching between inputs and outputs is established by parallel iteration algorithms usually used to implement maximal size matching,however,a matching of an input-output pair will be kept for a certain period after it was established and the length of the period is a function of the occupancy of the corresponding VOQ.Based on round-robin arbiters,an implantation scheme of MQWS algorithm is proposed.And then an extensive evaluation of the presented scheme is carried out.According to their implementation complexity and the results of the performance evaluation,the preferential weighted functions are proposed.With the complexity similar to maximal size matching,MQWS achieves comparable performance of maximal weight matching,i.e.throughput approaching 100% under both uniform and nonuniform traffic,even by single iteration.This result obviously outperforms those of iSLIP and EiSLIP.Hence,the scheme presented in this paper is more suitable for high performance input queued switches and routers.