摘 要采纳 MPLS 技术组建的 IP 主干网对 VPN 有着有力的支持,MPLS 技术可以在二、三层上实现VPN，但两种方法各有优缺点.文中描述了 MPLS 隧道技术的主要思想，分析了基于 MPLS 技术的二、三层 VPN 工作机制，比`较了 MPLS 二、三层 VPN 的工作特点．提出了要根据 VPN 网络设计性能和目标。合理选择基于 MPLS 技术的 VPN 方案组建所需要的 VPN。关键词：MPLS； 隧道技术； 二层 VPN； 三层 VPNAbstractIP backbone network based on MPLS provides a powerful backing for VPN．Though a VPN could be setup in layer2 or layer3，there ale advantages and disadvantages for both。Describes the main idea of MPLS tunnel technology．Analyzes the mechaIlism of layer2 and layer3 VPN based on MPLS．Comparesthe characteristics which ale possesd by hyer2 and hyer3 VPN．Proposes that on the basis of the property and target of network design a plan may be reasonably choosed to cornstruct the MPLS VPN needed by customers．Key Words：MPLS；tunnel technology；layer2 VPN;layer3 VPN目 录1。可行性分析.................................................................................................51.1 需求分析.....................................................................................................51。2 经济可行分析.........................................................................................62.MPLS 网络架构设计与关键技术讨论...............................................................72。1 MPLS 网络设计思想.................................................................................72.3 网络设计拓扑.............................................................................................82.4 MPLS................................................................................................................92。4.1 MPLS 架构中的设备分类....................................................................10LSR:.......................................................................
