简单计算ABR业务平均ACR的反馈流量控制算法  

Binary feedback traffic control algorithm based on simplified mean ACR calculation

作　　者：孙晓东[1] 冯振明[1] 

机构地区：[1]清华大学电子工程系,北京100084

出　　处：《清华大学学报（自然科学版）》2002年第7期881-884,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家"九七三"重点基础研究发展规划 (G19980 3 0 40 9)

摘　　要：为了提高异步传输网络中可用比特率 (ABR)业务的二进制反馈流量控制算法的综合性能 ,通过使用计算方法对现有流量控制算法的研究 ,提出了一种新的二进制反馈算法 -简单计算平均信元速率的比例速率控制算法 (SM-PRCA)。在该算法中 ,网络交换节点通过处理后向资源管理(RM)信元 ,向 ABR业务源传输最新的网络拥塞状况指示。当网络发生拥塞后 ,通过考察具体的物理链路拥塞程度和当前虚链路 (VC)的实际发送速率 ,有选择性地设置后向 RM信元中的拥塞指示 (CI)和不允许增加 (NI)字域。该算法通过仿真显示出了明显优于显式前向拥塞指示 (EFCI) ,以及在某些方面优于显式速率的增强比例速率控制算法(EPRCA)算法的性能。The performance of binary feedback flow control algorithms of available bit rate (ABR) traffic in asynchronous transfer mode (ATM) networks is improved using a new binary feedback algorithm developed from the explicit forward congestion indication (EFCI) algorithm and the enhanced proportional rate control algorithm. In the new algorithm, the switch node conveyes the current network congestion status to the ABR traffic source via backward resource management (RM) cells. During congestion, the switch selectively sets the congestion indication (CI) and no increate (NI) fields in backward RM cells according to the congestion degree and the available cell rate (ACR) of each virtual channel (VC) connection. Simulation results show that the new algorithm has evidently better performance than EFCI in bandwidth allocation fairness, system bandwidth utility and queue length. Also, this algorithm shows even better performance in some respects than the enhanced proportional rate control algoritam (EPRCA) algorithm based on the approximate mean ACR calculation.

关 键 词：ABR业务 反馈流量控制算法 可用比特率业务 显式前向拥塞指示 异步传输网络 计算方法 资源管理信元 增强比例速率控制算法 

分 类 号：TN915.2[电子电信—通信与信息系统]