A high-throughput scheduling algorithm for a buffered crossbar switch fabric

We examine high-throughput scheduling algorithms for buffered crossbar switch fabrics containing one buffer per crosspoint. We propose a scheduling system that uses longest queue first (LQF) scheduling for virtual output queues (VOQs) at the inputs and round-robin (RR) scheduling for the crosspoints. It is shown, through fluid model techniques, that this system achieves 100% throughput for input traffic that satisfies the strong law of large numbers and that produces a load /spl les/1/N for any input/output pair of an N/spl times/N switching fabric. Simulations indicate that 100% throughput may be attained for a much larger class of admissible loads.

[1]  Masayoshi Nabeshima.  Performance Evaluation of a Combined Input- and Crosspoint-Queued Switch , 2000 .

[2]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[3]  H. T. Kung,et al.  Credit-Based Flow Control for ATM Networks , 1994, SIGCOMM 1994.

[4]  Nick McKeown,et al.  Designing and implementing a fast crossbar scheduler , 1999, IEEE Micro.

[5]  Kai-Yeung Siu,et al.  Linear-complexity algorithms for QoS support in input-queued switches with no speedup , 1999, IEEE J. Sel. Areas Commun..

[6]  Nick McKeown,et al.  Scheduling algorithms for input-queued cell switches , 1996 .

[7]  Balaji Prabhakar,et al.  The throughput of data switches with and without speedup , 2000, Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064).