支持优先级的高速交换开关缓冲队列分析与设计

缓冲队列在交换开关中起着重要的作用。为了使交换开关的调度更加灵活有效,可以采用硬件方法实现缓冲排队。为了支持QOS,还有必要设计一种支持优先级的排队机制。该文在研究已有的缓冲排队方案基础上,提出一种支持优先级FIFO排队的硬件体系结构PFQ(PriorityFIFOQueue)。PFQ借鉴了移位寄存器的基本思想,按链表形式组织每个FIFO队列,通过设置高速局部总线,有效解决了头信元阻塞问题。使得采用PFQ的交换开关可以实现更加灵活的调度算法。模拟结果表明PFQ具有灵活、高效、硬件代价较低并且实现简单的优点。

A Priority Buffering Queue Architecture in High-Speed Switch

It is evident that an efficient buffering and queueing scheme play a key role in the performance of the switch.In order to make the schedulers flexible and effective,it is necessary to implement buffering queue by hardwardware.Moreover to guarantee quality of service(QoS),it is necessary to design a buffering queue architecture that supports priority schedule.This paper proposes a priory FIFO queue architecture PFQ after studying conventional buffering and queueing techniques.It is based on the basic idea of shift register.Each priority FIFO queue is organized as a linked list.It solves the HOL(Head of Line)problem efficiently by setting the high-speed local bus.Using PFQ in the switch,a much more flexible scheduling algorithm can be adopted.Simulation results show that PFQ is highly flexible and efficient at a low hardware expense.