VPLS, Virtual Private LAN Service Overview
Virtual Private LAN Service, also known as VPLS, is a Layer 2 Ethernet VPN technology that allows businesses to connect multiple Ethernet sites over MPLS or metro networks. With VPLS Ethernet, all customer sites appear to be on the same Local Area Network (LAN) regardless of geographical location. Each customer site has its own private VPLS that is separate from other customers across the shared customer network. Virtual Private LAN Service VPLS overcomes the limitations set forth by legacy networking technologies such as ATM and frame relay by providing a protocol transparent, any-to-any, fully meshed service across a Wide Area Network (WAN).
VPLS is based on an Ethernet interface which simplifies the LAN/WAN boundary for both service providers and customers. As a result, Virtual Private LAN Service (VPLS) allows for rapid deployment because the service bandwidth is not tied to the physical interface. VPLS supports a wide range of speeds from 1Mb to 10Gb of burstable bandwidth.
What is VPLS and how does it work? VPLS uses edge routers that can learn, bridge and replicate at each VPLS location. The VPLS edge routers are connected via fully meshed MPLS LPS tunnels, enabling any-to-any connectivity. With VPLS Ethernet, multiple services can be carried within each LPS tunnel. Furthermore, all services in the VPLS tunnel are identified by a unique virtual channel label, which is exchanged at each pair of VPLS edge routers. The VPLS routers switch traffic based solely on the label, so the virtual channel is only visible to the final edge router where the traffic terminates. With VPLS Ethernet, edge routers are only exposed to a single MAC address at each location which allows for the scalability to support thousands of VPLS locations.
There are many benefits associated with VPLS Ethernet. VPLS offers a transparent, protocol independent multipoint solution with shared bandwidth pool for remote locations that belong to a specific customer VPLS domain. With VPLS Ethernet, customers maintain complete control over their own switching and routing between locations. This allows for easier configuration and debugging. VPLS also eliminates the Layer 2 protocol conversions between LAN and WAN. VPLS requires less training for IT staff and network administrators than legacy WAN technologies such as ATM and frame relay. Furthermore, VPLS utilizes auto discovery to add additional locations without reconfiguring existing locations. VPLS also offers bandwidth provisioning for each subscriber independent of the VPLS network.
