Ethernet Virtual Private LAN Service (E-LAN)

Many large service providers have embraced Ethernet technology as the demand for interconnecting remote high speed Ethernet LANs across a Metropolitan Area Network or Wide Area Network have grown. Ethernet deployment success has been attributed to its simplicity, effectiveness, and low cost. Service providers can also be more responsive to meeting their customer’s requests for new services with shorter lead times eliminating the threat of competition. This will enable service providers to attract enterprise customers who want virtual private networks and who might have previously run their own private networks.

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The HSX 6000 provides support for VPLS, thus allowing Service Providers to offer Ethernet/MPLS Virtual Private Network services, and providing VPN services to customers for connecting geographically remote sites.

The advent of VPLS provides a transparent multipoint Ethernet LAN service or Layer 2 Virtual Private Network for a customer as if they had their own private network. For the enterprise customer, this has two advantages over Layer 3 IP VPN services: 1) they can get transport for both IP and non-IP traffic; and 2) they don't have to give up control of their Layer 3 IP network.  

For the Service Provider, the entire network appears as a single logical learning bridge for each VPLS instance that the Service Provider network supports.   However the Service Provider can now support enterprise customers and connect them to their separate LANs because the connections behave as independent learning bridges. Just as a learning bridge learns MAC addresses on its ports, VPLS bridges learn MAC addresses at each PE (Provider Edge). Multiple VPLS service instances can be supported on a single PE Node.

At each VPLS PE node, a Virtual Switch Instance (VSI) is instantiated that allows the PE to participate in a VPLS service instance. A VSI is a local virtual Ethernet Switch for a given VPLS service. The VSIs belonging to the same VPLS service are interconnected with a full mesh of Pseudowires to form an emulated Multipoint Ethernet LAN, or a VPLS instance.  The Pseudowires terminate at the VSIs and use standard MPLS signaling protocols.

The HSX 6000 will enable Service Providers to provide robust guarantees to their end users and manage high volumes of traffic with the VPLS QoS. This function includes the ability to offer 8 different priority classes for QoS based upon 802.1p CoS bits. The customer traffic from the attachment circuits will perform classification, policing and shaping on a per-packet basis. These features allow service providers to provide a robust differentiated service.