US 8018880

US Patent 8,018,880: Layer 2 Virtual Private Network over PBB-TE/PBT and Seamless Interworking with VPLS

Title: Layer 2 virtual private network over PBB-TE/PBT and seamless interworking with VPLS

Assignee: The current assignee is K.MIZRA LLC, as of January 13, 2020. The original assignee was Brixham Solutions Ltd.

Inventors: Norival R. Figueira and Richard D. Gitlin.

Filing Date: March 25, 2008 (Application number US12/079,413).

Issue Date: September 13, 2011.

Abstract: The patent describes a Layer 2 Virtual Private Network (L2VPN) system utilizing a Provider Backbone Bridge (PBB) network. This network connects multiple sites via provider backbone trunks, specifically Provider Backbone Transport (PBT) or Provider Backbone Bridge Traffic Engineering (PBB-TE) trunks, to form the L2VPN.

Plain-Language Overview of Independent Claims:

The patent includes four independent claims covering methods, systems, and computer program products related to L2VPNs over PBB/PBT networks, particularly focusing on interworking with MPLS-based Virtual Private LAN Services (VPLS) and handling traffic between different PBB network segments.

• Independent Claim 1 (Method): This claim details a method for setting up an L2VPN. It involves connecting various sites within a PBB network using PBT or PBB-TE trunks. Virtual Switch Instances (VSIs) are provisioned for these sites using a control plane located externally to the sites. Crucially, a specific "split horizon" rule is used to manage frame forwarding at a VSI that links the PBB network to a Multi Protocol Label Switching (MPLS) network. This rule dictates:

  1. Frames arriving from a Service Instance on a PBB trunk can only be sent to Pseudowires (MPLS paths) or customer connections.
  2. Frames arriving from a Pseudowire (MPLS path) can only be sent to Service Instances on PBB trunks or customer connections.
  3. Frames arriving from a customer connection are forwarded normally by the VSI without any restrictions.

• Independent Claim 14 (System): This claim describes a system designed to implement the method of Claim 1. It comprises:

  1. A connector to link PBB network sites using PBT or PBB-TE trunks.
  2. A controller that interfaces with an external control plane to provision VSIs for the sites.
  3. A first VSI configured to apply the specific split horizon rule (as described in Claim 1) when handling frames at the interface between the PBB network and an MPLS network.

• Independent Claim 26 (Computer Program Product): This claim covers a non-transitory computer-readable storage medium containing instructions. When executed, these instructions cause a system to perform the method outlined in Claim 1, encompassing the coupling of PBB sites, external provisioning of VSIs, and the application of the defined split horizon rules for PBB-MPLS interworking.

• Independent Claim 39 (Method): This claim presents another method for interconnecting an L2VPN system within a PBB network, specifically when connecting a PBB core network to a PBB metro network. It involves:

  1. Coupling PBB network sites using PBT or PBB-TE trunks.
  2. Provisioning VSIs via an external control plane.
  3. Employing a split horizon rule at a VSI connecting the PBB core and metro networks. This rule ensures:
     • Frames from a PBB metro network Service Instance can only be forwarded to PBB core network Service Instances or customer interfaces.
     • Frames from a PBB core network Service Instance can only be forwarded to PBB metro network Service Instances or customer interfaces.
     • Frames from a customer interface are forwarded normally by the VSI without restrictions.

CAFC 2026 Docket Search:

As of April 26, 2026, a search of the CAFC 2026 dockets did not yield specific litigation records directly referencing US patent 8,018,880. General patent-related Federal Circuit activity and other patent infringement cases were found, but no authoritative information specifically linking this patent to ongoing litigation in the CAFC for 2026 was identified.