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论文类型：期刊论文

发表时间：2009-08-01

发表刊物：IEEE TRANSACTIONS ON COMMUNICATIONS

收录刊物：SCIE、EI、Scopus

卷号：57

期号：8

页面范围：2420-2429

ISSN号：0090-6778

关键字：Load-balanced switches; throughput

摘要：The load-balanced (LB) switch proposed by C.S. Chang et al. [1], [2] consists of two stages. First, a load-balancing stage converts arriving packets into uniform traffic. Then, a forwarding stage transfers packets from the linecards to their final output destination. Load-balanced switches do not need a centralized scheduler and can achieve 100% throughput or a broad class of traffic distributions. However, load-balanced switches may cause packets at the output port to be out of sequence. Several schemes have been proposed to tackle the out-of-sequence problem of the load-balanced switch. They are either too complex to implement, or introduce a large additional delay. In this paper, we present a practical load-balanced switch, called the Byte-Focal switch, which uses packet-by-packet scheduling to significantly improve the delay performance over switches of comparable complexity. We prove that the queues at the input need only finite buffering, and that the overall switch is stable under any traffic matrix. Our analysis shows that the average queuing delay is roughly linear with the switch size N, and although the worst case resequencing delay is N-2, the average resequencing delay is much smaller. This means that we can reduce the required resequencing buffer size significantly.