Lower Bounds for Wide-Sense Non-blocking Clos Network

  • Kuo-Hui Tsai
  • Da-Wei Wang
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1449)


The 3-stage Clos network is generally considered the most basic multistage interconnecting network(MIN). The nonblocking property of such network has been extensively studied in the past. However there are only a few lower bound results regarding wide-sense nonblocking. We show that in the classical circuit switching environment, for large r to guarantee wide-sense nonblocking, 2n − 1 center switches are necessary where r is the number of input switches and n is the number of inlets of each input switch. For the multirate environment, we show that for large enough r any 3-stage Clos network needs at least 3n − 2 center switches to guarantee wide-sense nonblocking. Our proof works for even 2-rate environment.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • Kuo-Hui Tsai
    • 1
  • Da-Wei Wang
    • 1
  1. 1.Institute of Information ScienceAcademia SinicaNankang, TaipeiTaiwan, ROC

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