MPLS VPN Technology参考.pptVIP

Implementation of Frame Mode MPLS MPLS VPN Technology VPN Taxonomy VPN Models VPN services can be offered based on two major models:两种主要的可以提供的VPN服务模型: Overlay VPNs, in which the service provider provides virtual point-to-point links between customer sites覆盖VPNs, 此种模式下服务提供商为客户站点提供了点到点的连接. Peer-to-peer VPNs, in which the service provider participates in the customer routing对等体到对等体VPNs,此种模式下服务提供商将参与客户端路由. Overlay VPNs: Frame Relay Example Overlay VPNs: Layer 3 Routing The service provider infrastructure appears as point-to-point links to customer routes.服务提供商的基础架构向客户路由器提供了点到点的连接. Routing protocols run directly between customer routers.路由协议直接在客户路由器间运行. The service provider does not see customer routes and is responsible only for providing point-to-point transport of customer data.服务提供商不参与客户路由同时其仅仅为客户数据提供点到点的传输. Peer-to-Peer VPNs Benefits of VPN Implementations Overlay VPN: Well-known and easy to implement容易实现 Service provider does not participate in customer routing服务提供商不参与客户的路由操作 Customer network and service provider network are well-isolated客户的网络和服务提供商的网络是独立的 Peer-to-peer VPN: Guarantees optimum routing between customer sites为客户提供最有效的路由 Easier to provision an additional VPN容易提供额外的VPN功能 Only sites are provisioned, not links between them仅仅是基于站点的,并没有具体的专有连接位客户站点之间 Drawbacks of VPN Implementations Overlay VPN: Implementing optimum routing requires a full mesh of VCs.需要全网状的VCs才可以实现最佳路由. VCs have to be provisioned manually.VCs需要手工的建立. Bandwidth must be provisioned on a site-to-site basis.基于站点到站的带宽供应 Overlay VPNs always incur encapsulation overhead (IPsec or GRE).覆盖VPNs通常会导致额外的封装负载.比如IPsec或者GRE. Drawbacks of VPN Implementations (Cont.) Peer-to-peer VPN: The service provider participates in customer routing.服务提供商参与到客户路由过程中. The service provider becomes responsible for customer convergence.服务提供商需要负责客户端路由收敛. PE routers carry all routes from all customers.PE路由需要承载所有客户的路由条目. The service provider needs detailed IP routing knowledge.服务提供商需要深层的IP路由技术. Drawbacks