The VPLS architecture proposed in draft-ietf-ppvpn-vpls-ldp-0x.txt specifies the use of provider equipment (PE) that is capable of learning, bridging, and replication on a per-VPLS basis. The PE routers that participate in the service are connected using MPLS Label Switched Path (LSP) tunnels in a full-mesh composed of mesh SDPs or based on an LSP hierarchy (Hierarchical VPLS (H-VPLS)) composed of mesh SDPs and spoke SDPs. The 7210 SAS supports only H-VPLS.
Multiple VPLS services can be offered over the same set of LSP tunnels. Signaling specified in RFC 4905 is used to negotiate a set of ingress and egress VC labels on a per-service basis. The VC labels are used by the PE routers for de-multiplexing traffic arriving from different VPLS services over the same set of LSP tunnels.
H-VPLS is provided over MPLS by:
connecting the 7210 SAS-R6 and 7210 SAS-R12 to bridging-capable provider edge (PE) routers through a spoke-SDP. The PE routers are connected using a full mesh of LSPs.
negotiating per-service VC labels using draft-Martini encapsulation
replicating unknown and broadcast traffic in a service domain
enabling MAC learning over tunnel and access ports (see VPLS MAC learning and packet forwarding).
using a separate forwarding information base (FIB) per VPLS service