Performance of Maximal-size Matching Schemes with Occupancy-based Frame Eligibility

摘要

Input-queued (IQ) switches are attractive becausernthey work without the speedup requirement of an output-queuedrn(OQ) switch. Virtual output queues (VOQs) are widely usedrnby input-queued (IQ) switches to eliminate the head-of-linern(HOL) blocking phenomena, which limits matching and switchingrnperformance. With the use of VOQs, the performance of a switchrnmainly depends on the employed matching scheme. An effectivernmatching scheme for IQ switches with VOQs must providernhigh throughput under several admissible traffic patterns andrnfeasible implementation complexity. In this paper, we introducerna frame eligibility concept for maximal-size matching schemes.rnEligible packets are the only ones considered for matching. Wernstudy pre-existing maximum-size matching schemes that have lowrncomplexity and have been shown to deliver low throughput underrntraffic with uniform distributions. We show via simulation thatrnsimple matching schemes, such as parallel iterative matchingrn(PIM) and basic round-robin matching (RRM) deliver highrnthroughput under uniform and a nonuniform traffic pattern,rncalled unbalanced, when using the presented concept. The newrnmatching schemes are named unlimited frame PIM (uFPIM) andrnunlimited frame RRM (uFRRM).