针对传统Internet 在流量工程方面的不足和越来越多新业务对流量工程的需求,文章分析了DiffServ 在MPLS流量工程方面的应用,详细介绍了实现DiffServ 流量工程中的两种带宽限制模式——MAM和RDM,并从减少抢占和重路由的系统开销出发提出了一种新的带宽约束模型SAM。通过对它们的管理、效率等方面比较,得出MAM、RDM 和SAM 各自的适用范围。 关键词 区分业务,多协议标签交换,流量工程,带宽限制 Abstract The bandwidth constraint mechanism and available range in Differv MPLS traffic engineering will be discussed. A new bandwidth constraint mechanism SAM will be presented in order to reduce system cost for preemption and rerouting. This model will be compared with other two mechanism-MAM and RDM. Keywords DiffServ, MPLS, Traffic Engineering, Bandwidth Constraint