Kompella BGP Layer 2 VPN is a highly scalable approach to signalling MPLS Layer 2 VPNs. In a similar way to the Layer 3 VPN approach the standard uses MP-BGP to signal the VPN by means of a specific AFI/SAFI address family (25/65).
The Kompella approach allows auto provisioning of circuits within a VPN mesh. Circuit ids, VPN labels and notification to other routers in the mesh are all handled by the Kompella BGP signalling approach. The BGP L2 VPN uses the Martini encapsulation approach. A Martini control word is carried instead of the native L2 header when the frames are carried across the MPLS core.
Standards for L2 VPNs
draft-kompella-l2vpn-l2vpn (BGP L2), RFC 4447 (LDP L2 Circuit), RFC 4761 (BGP VPLS), RFC 4762 (LDP VPLS)