VPLS Extensions for Provider Backbone Bridging
IEEE 802.1ah draft standard [IEEE802.1ah], also known as Provider Backbone Bridges (PBB) defines an architecture and bridge protocols for interconnection of multiple Provider Bridge Networks (PBNs). PBB was defined in IEEE as a connectionless technology based on multipoint VLAN tunnels. MSTP is used as the core control plane for loop avoidance and load balancing. As a result, the coverage of the solution is limited by STP scale in the core of large service provider networks. Virtual Private LAN Service (VPLS) [RFC4762] provides a solution for extending Ethernet LAN services, using MPLS tunneling capabilities, through a routed MPLS backbone without running (M)STP across the backbone. As a result, VPLS has been deployed on a large scale in service provider networks. This draft discusses extensions to the VPLS model required to incorporate desirable PBB components while maintaining the Service Provider fit of the initial model.