VPWS Provider Edge Devices

In a VPWS configuration, E-series routers function as provider edge devices, which are also referred to as PE routers. These PE routers perform a similar function to PE routers in a BGP/MPLS VPN configuration.

Figure 131 depicts two PE routers: PE 1, which is the local router, and PE 2, which is the remote router located at the other side of the service provider core. Each PE router must have an VPWS instance configured for each L2VPN in which it participates. Consequently, the sample topology comprises four separate VPWS instances: instances l2vpnA and l2vpnB configured on PE 1, and instances l2vpnA and l2vpnB configured with matching route target values on PE 2.

Each VPWS instance configured on the router is associated with two types of interfaces. The CE-facing or customer-facing interface is a layer 2 interface that directly connects the PE router to a local CE device. The router encapsulates layer 2 frames from the CE device in an MPLS packet and then forwards the encapsulated frames to the service provider core from an MPLS interface through the provider (P) router. This encapsulation is identical to Martini encapsulation for layer 2 services over MPLS.

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