摘要
信元丢弃机制是缓解和消除ＡＴＭ网络结点拥塞的有效方法之一，但现有的信元丢弃策略均未考虑信元丢弃与网络资源利用率之间的关系，因而导致当有信元丢弃时，语义敏感型业务的网络资源利用率和信元丢失率等指标都较差．着眼于从信元到达一个ＡＴＭ网络结点时已耗费网络资源量的相对大小，文中提出了一种旨在克服传统信元丢弃策略诸缺陷的新策略：基于“转发强度”的信元丢弃策略，对该策略和现有的两种典型信元丢弃策略以Ｍａｒｋｏｖ链为工具分析了网络资源利用率和信元丢失率指标，结果表明：由于选择对网络资源相对消耗量最小的信元进行丢弃，该策略能够提高对网络资源的利用率，降低信元丢失率，同时减少因丢弃信元而造成的信元重发量，从而最终缓解网络拥塞程度及减小结点再度拥塞的可能性．
A cell discard scheme serves as an effective method in either alleviating or eliminating network congestion in ATM network nodes. Existing cell discard strategies, however,do not consider the relationship between cell discarding and network utilization. Consequently, they lead to poor measures of both the average network utilization and the cell loss ratio concerning user services sensitive to semantics. From the viewpoint of the relative volume of network resources having been consumed by a cell arriving at a certain ATM network node, a new cell discard strategy, the forwardingstrengthbased one, is proposed in the paper here, with removal of the above defects as its objective. By using the Markov model, the average network utilization and the cell loss ratio are analyzed with respect to the proposed cell discard strategy and the two classical ones available. The results show that by discarding cells having consumed minimal network resources, this new strategy can improve network performance through increasing the network utilization ratio, decreasing the cell loss ratio and cell retransmission volumes, alleviating network congestion, and reducing the possibility of recongestion in ATM network nodes.
出处
《计算机研究与发展》
EI
CSCD
北大核心
1999年第5期625-631,共7页
Journal of Computer Research and Development
基金
电子科学研究院电子预研基金
关键词
信元丢弃策略
异步传输模式
B-ISDN
ATM网络
asynchronous transfer mode(ATM),quality of service (QoS),cell discard,cell loss ratio (CLR),cell loss priority (CLP)
