The iTFF scheduling algorithm for input-queued switches

In input-queued scheduling, the iSLIP algorithm. is a milestone for its high throughput and low implementation complexity. However, under bursty arrivals, its average input latency increases dramatically and quite a few cells can be dropped as the input buffer overflows. Motivated by cutting down the cell loss rate without increasing the average input latency, we present a new scheduling algorithm, called iTFF (iterative "time-to-leave" and "full-or-not" first), which has better performance than iSLIP under bursty traffic conditions. Simulation results indicate that iTFF restrains the cell loss rate exponentially and yet maintains low average input latency. Moreover, iTFF can be implemented in hardware to achieve high speed. Two implementation schemes of the algorithm are also presented.