中文摘要：

CICQ交换结构因具有良好的分布式调度特性而成为构建太比特（Tb／s）级以上交换机的一种理想选择．轮转型调度算法因硬件实现的简单性而得到广泛的研究，尽管此类型的调度算法在均匀流量下具有较高的吞吐率，然而在非均匀的流量下其性能则明显下降．指出了已有轮转型算法在非均匀流量下性能下降的原因，提出了一类基于双指针的轮转型调度算法，即每个输入调度器均有两个轮转指针（主指针和辅助指针）．主指针对应的队列具有最高的调度优先级，算法可以根据各个队列的状态动态决定何时更新主指针。当主指针对应的队列被流控机制阻塞时，将根据辅助指针依次公平服务其他队列．实验结果表明，基于双指针的调度算法可以显著提高CICQ交换机在非均匀流量下的性能．

英文摘要：

The CICQ switch fabric is an ideal solution to multi-terabit switch implementation owing to its nice distributed scheduling property. Round-robin algorithms have been extensively studied because of their simplicity for hardware implementation. It is known that round-robin algorithms provide high throughput under uniform traffic; however, the performance is degraded under nonuniform traffic. In this paper, the reason for the performance degradation of the existing round-robin algorithms is pointed out and then a class of dual round-robin algorithms is proposed. For the proposed algorithms, each input arbiter is associated with dual round-robin pointers named the primary pointer and the secondary pointer respectively. The input queue corresponding to the primary pointer has the highest priority being scheduled, and the decision for updating the primary pointer can be dynamically made relying on the input queue status. When the input queue corresponding to the primary pointer is blocked, other input queues can be uniformly scheduled according to the secondary pointer position. Simulations show that the dual round-robin algorithms can significantly improve the performance of the CICQ switch under nonuniform traffic.