A practical scheduling algorithm for input-buffered switch

Input-buffering is preferentially used in high-speed commercial and experimental routers and switches. The cell scheduling algorithms are critical components in input-buffered switches. They have a significant impact on the throughput, stability and guaranteed quality of service (QoS) of input-buffered switches. The longest queue first (LQF) algorithm can achieve 100% throughput for input-buffered switches, but is not starvation-free. That is, there are some queues will never be serviced. This paper proposes a modified LQF algorithm called mLQF. It can achieve 100% throughput and is starvation-free.