MPLS and VPN Architectures, Volume II

Connection-Oriented VPNs

Connection-oriented VPNs were the first ones to be introduced. They offer a number of clear advantages, including the following:

• The service provider does not need to understand the customer's network; the service provider just provides virtual circuits between the customer sites.

• The service provider is not involved in the customer's routing (as shown in Figures 1-2 and 1-3), and it doesn't need to know which Layer 3 protocols the customer is deploying. Consider, for example, the network shown in Figure 1-2. The VPN network is implemented with Frame Relay VCs; therefore, the service provider is unaware of the routing protocols that the customer is using. From the customer's routing perspective, the customer routers are ...