IETF RFC 4761
Virtual Private LAN Service (VPLS) Using BGP
for Auto-Discovery and Signaling
This IETF Request For Comments (RFC) provides useful background information on the transport of Carrier Ethernet services over VPLS networks.
Abstract:
"Virtual Private LAN Service (VPLS), also known as Transparent LAN Service and Virtual Private Switched Network service, is a useful Service Provider offering. The service offers a Layer 2 Virtual Private Network (VPN); however, in the case of VPLS, the customers in the VPN are connected by a multipoint Ethernet LAN, in contrast to the usual Layer 2 VPNs, which are point-to-point in nature. This document describes the functions required to offer VPLS, a mechanism for signaling a VPLS, and rules for forwarding VPLS frames across a packet switched network."
More links relating to VPLS can be found at the Wikipedia page on this topic.