基于动态缓冲阈值的Internet区分服务

Differentiated Services for the Internet Based on Dynamic Buffer Thresholds

该文提出了一种将 Internet网络分组传输延时和丢失控制的区分服务要求合并在一起的综合方案 .在这个方案中 ,分组丢失控制是基于动态缓冲阈值 ( dynamic buffer threshold,简称 DBT)方案 .在 DBT方案中 ,缓冲控制阈值基于分组丢失行为而动态地变化 .在静态缓冲阈值 ( static buffer threshold,简称 SBT)方案中 ,分组丢失变化没有控制 ,丢失率变化大 .对于缓冲控制阈值的确定 ,没有简明的数学表达方式 .由于 SBT不能随着传输突发特性的变化而变化 ,从而影响网络的系统性能 .该文提出的 DBT方案不但可以克服这些问题 ,而且可以确定和控制标志分组与非标志分组丢失率之间的比例关系 .文章给出了所提出方案的随机 Petri网性能模型。

A new integrated scheme of differentiated services for the Internet is proposed in this paper. In this scheme, a service which combines both delay and drop priority is provided to applications with clear service differentiation. The integrated scheme is based on the dynamic buffer threshold (DBT) scheme. In the DBT scheme, the threshold is dynamically varied in run time based on the packet loss behaviors. In the static buffer threshold (SBT) scheme, the variation of packet loss probabilities can be very large and there is no simple mathematical expression relating the threshold to the desired packet loss rate. These problems are overcome with the DBT scheme. In this paper, the performance model of the scheme is given using stochastic Petri nets and is analyzed by simulation.