Input Queuing A Single Iteration Of Exchange Of The Scheduling Algorithm

High-speed switch technique plays a dominative role in the research of high-speed switches. The study of high-performance switch scheduling algorithm becomes more and more popular, and it obtains many remarkable achievements.Virtual Output Queuing (VOQ) crossbar switches have been demonstrating advantages as high speed switch. They eliminate the head-of-line (HOL) blocking, which limits the maximum throughput of single input queuing switches, and do not require switching fabrics with speedup capability, which prevents output queuing switches from being implemented cheaply. Existing practical RR scheduling algorithms work in an iterative manner, and each iteration usually includes three steps: request, grant and accept. Since iSLIP algorithm which stands for this typical algorithm is proposed, some improvements have been done.In the beginning of this paper, switch architectures and queuing fabric are introduced, and then traditional scheduling algorithms used in virtual output queuing crossbar switch are presented, and then iSLIP2 algorithm is deeply studied and analyzed. Based on iSLIP2 algorithm, this paper proposes a new switch scheduling algorithm--C_SLIP2 (Change_SLIP2). By incorporating arbitration into the request step, the accept step can be eliminated, and Direct Matching step is added as the third step. The new scheduling algorithm can achieve maximal matching within one iteration and improves three step algorithms. In the end, this paper tests the average delay and scheduling efficiency of C_SLIP2 algorithm and other scheduling algorithms under Poisson uniform traffic, Bernoulli uniform traffic and ON/OFF burst traffic by simulation, and compares performances with other scheduling algorithms. The experiment results show C_SLIP2 algorithm has lower average delay and higher scheduling efficiency than other scheduling algorithms.