VPLS

Virtual Private LAN Service (VPLS) is a way to provide Ethernet-based multipoint to multipoint communication over or MPLS networks. It allows geographically dispersed sites to share an Ethernet broadcast domain by connecting sites through pseudowires. The term 'sites' includes multiplicities of both servers and clients. The technologies that can be used as pseudo-wire can be Ethernet over MPLS, L2TPv3 or even GRE. There are two IETF standards track RFCs (RFC 4761 and RFC 4762) describing VPLS establishment.

VPLS is a virtual private network (VPN) technology. In contrast to L2TPv3, which allows only point-to-point layer 2 tunnels, VPLS allows any-to-any (multipoint) connectivity.

In a VPLS, the local area network (LAN) at each site is extended to the edge of the provider network. The provider network then emulates a switch or bridge to connect all of the customer LANs to create a single bridged LAN.

VPLS is designed for applications that require multipoint or broadcast access.

Since VPLS emulates a LAN, full mesh connectivity is required. There are two methods for full mesh establishment for VPLS: using (BGP) and using (LDP). The "control plane" is the means by which provider edge (PE) routers communicate for auto-discovery and signalling. Auto-discovery refers to the process of finding other PE routers participating in the same VPN or VPLS. Signalling is the process of establishing pseudowires (PW). The PWs constitute the "data plane", whereby PEs send customer VPN/VPLS traffic to other PEs.

...
Wikipedia