US Patent 7860112 Bi-directional forwarding in ethernet-based service domains over networks

Techniques are described for providing hybrid forwarding within an Ethernet-based service domain established over one or more intermediate networks, such as a service provider (SP) network. For example, the Ethernet-based service domain may comprise a virtual private local area network service (VPLS) domain. A hybrid VPLS domain may transport layer two (L2) communications, such as Ethernet packets, between remote customer networks via the SP network. The techniques described herein enable a network device, e.g., a router, within a SP network to forward packets from a source device of a hybrid VPLS domain toward one or more subscriber devices of the hybrid VPLS domain (i.e., in a downstream direction) using P2MP forwarding semantics. The same network device forwards packets from one of the subscriber devices toward the source device (i.e., in an upstream direction) using P2P forwarding semantics.