IETF RFC 4761 PDF

Scope of This Document

This document has four major parts: defining a VPLS functional model; defining a control plane for setting up VPLS; defining the data plane for VPLS (encapsulation and forwarding of data); and defining various deployment options.

The functional model underlying VPLS is laid out in Section 2. This describes the service being offered, the network components that interact to provide the service, and at a high level their interactions.

The control plane described in this document uses Multiprotocol BGP [4] to establish VPLS service, i.e., for the auto-discovery of VPLS members and for the setup and teardown of the pseudowires that constitute a given VPLS instance. Section 3 focuses on this, and also describes how a VPLS that spans Autonomous System boundaries is set up, as well as how multi-homing is handled. Using BGP as the control plane for VPNs is not new (see [14], [6], and [11]): what is described here is based on the mechanisms proposed in [6].

The forwarding plane and the actions that a participating Provider Edge (PE) router offering the VPLS service must take is described in Section 4.

In Section 5, the notion of 'decoupled' operation is defined, and the interaction of decoupled and non-decoupled PEs is described. Decoupling allows for more flexible deployment of VPLS.