虚拟时钟调度算法研究

FIFO队列调度算法由于实现简单、执行效率高而在网络中得到大量的应用，但FIFO队列无法实现对资源的分配；男种调度算法公平队列调度则可以实现对带宽资源的公平分配，但是它存在可扩展性问题。而基于虚拟时钟的算法在实现对资源进行公平分配的同时具备良好的可扩展性，从而能够满足QoS控制中对于分组调度算法的需求。本文主要对一些基于虚拟时钟的度算法进行了分析和讨论，这也是进行QoS控制研究的基础。

STUDY OF VIRTUAL CLOCK PACKET SCHEDULING ALGORITHM

FIFO scheduling algorithm is widely used in the networks because of its simplicity and high performance.But it cannot perform resource allocation.Another scheduling algorithm,which is fair queuing scheduling algorithm (FQ),can perform fair resource allocation among different flows,but it also has a shortcoming of non-scalability.However,the virtual clock-based packet scheduling algorithm can perform resource allocation as long as maintain good scalability.In this paper,several virtual clock-based scheduling algorithms were discussed,and this task was the basis of how to combine these algorithm with QoS control mechanism.