Virtual Private LAN Service (VPLS) is a class of virtual private network service that allows the connection of multiple sites in a single bridged domain over a provider-managed IP/MPLS network. The customer sites in a VPLS instance appear to be on the same LAN, regardless of their location. VPLS uses an Ethernet interface on the customer-facing (access) side which simplifies the LAN/WAN boundary and allows for rapid and flexible service provisioning.
VPLS provides a balance between point-to-point Frame Relay service and outsourced routed services. VPLS enables each customer to maintain control of their own routing strategies. All customer routers in the VPLS service are part of the same subnet (LAN) which simplifies the IP addressing plan, especially when compared to a mesh constructed from many separate point-to-point connections. The VPLS service management is simplified since the service is not aware of nor participates in the IP addressing and routing.
A VPLS service provides connectivity between two or more SAPs on one (considered a local service) or more (which is considered a distributed service) service routers. The connection appears to be a bridged domain to the customer sites so protocols, including routing protocols, can traverse the VPLS service.
Other VPLS advantages include:
VPLS is a transparent, protocol-independent service.
There is no Layer 2 protocol conversion between LAN and WAN technologies.
There is no need to design, manage, configure, and maintain separate WAN access equipment, therefore, eliminating the need to train personnel on WAN technologies such as Frame Relay.
The 7210 SAS-D, 7210 SAS-Dxp, and 7210 SAS-K 2F1C2T do not support IP/MPLS uplinks and support only local VPLS service. These devices support provisioning of access SAPs or access-uplink SAPs to connect to the provider edge IP/MPLS routers, allowing users to provision an end-to-end VPLS VPN service using the concept of hierarchical VPLS.
The 7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C support IP/MPLS uplinks and support both local VPLS service and distributed VPLS service. This provides an option to use VPLS service configured on the node with spoke-SDPs to connect to the provider edge IP/MPLS routers or use access SAPs or access-uplink SAPs to connect to the provider edge IP/MPLS routers, allowing users to provision an end-to-end VPLS VPN service using the concept of hierarchical VPLS. The 7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C also support mesh SDPs for use in smaller network configurations.