ATM网络中基于“转发强度”的信元丢弃策略研究

信元丢弃机制是绘解和消除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，因而导致当前信元丢弃时，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。

STUDY OF THE

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.