ATM时钟同步的研究与实现

Research and Implementation of ATM Clock Synchronization

容错状态下的时钟同步是 ATM系统中的重要问题。本文分析了 ATM用户连接的要求 ,提出了与业务类型相关的调度模型 ,它能够满足用户信元的实时传输、发送顺序和信元丢失要求。由于同时考虑了信元的优先级和时限 ,不同传输和丢弃优先级但有相同实时传输要求的信元连接可以同时得到服务。最后 ,根据容错实时系统的要求 ,本文提出了一种容错状态下实现同步的调度方案 。

Clock synchronization in ATM networ ks is an important problem especially in a fault tolerant condition.In this pap er the demands for ATM connection are analyzed and a scheduling model based on s ervice types is proposed.With this model,the user's demands for real time trans fe r,sending order and cell loss can be met.Because the priority and the time deadl ine are considered at the same time,cells of different priorities but of the sam e time deadline can be served at the same time.Finally,a scheduling method is ad dressed,which is proved to be effective when faults happen.