PBB-TE L2VPN Rapid Traffic Restoration and Route Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solutions for creating Layer 2 Virtual Private Networks (L2VPNs) over Ethernet networks face issues such as slow recovery times after link failures and lack of control over routes, as they rely on Spanning Tree Protocol (STP) and Multi-Protocol Label Switching (MPLS), which are not suitable for service providers requiring rapid traffic restoration and full control over network paths.
Innovation Solution
Implementing Provider Backbone Bridge (PBB) networks with Provider Backbone Transport (PBT) trunks and an external control plane to create L2VPNs that do not rely on STP, allowing for rapid traffic restoration and providing service providers with control over route provisioning through a full mesh of PBT trunks and Service Instances, while also enabling seamless interworking with VPLS over MPLS/IP networks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Spanning Tree Protocol (STP) is used to restore traffic after link failures, then traffic restoration is achieved, but the recovery time is slow (seconds instead of tens of milliseconds)
Solution Approach 1:
The patent segments the network control into two independent parts: a fast reactive layer using PBB-TE for immediate traffic restoration (achving <50ms) and a slow provisioning layer using VPLS/MPLS for route management. This segmentation allows the restoration function to operate independently from the control plane, eliminating STP's slow convergence while maintaining route control through the provisioning layer.
Solution Approach 2:
The patent introduces PBB-TE as an intermediary layer between the physical network and the VPLS control plane. This intermediary provides fast failover capabilities independent of STP while VPLS continues to provide route provisioning and management, thus resolving the contradiction between fast restoration and route control.
2Adaptability or versatility
If VPLS over MPLS is used to create L2VPNs, then routes are dynamically set up, but service providers lack control over provisioned routes and backup routes
Solution Approach 1:
The patent segments the routing control function from the restoration function. VPLS over MPLS handles high-level route provisioning and backup route configuration (providing control), while PBB-TE handles dynamic path selection and fast rerouting (providing adaptability). This segmentation allows service providers to maintain route control through VPLS while achieving fast dynamic restoration through PBB-TE's independent control plane.
Solution Approach 2:
PBB-TE acts as an intermediary that translates VPLS provisioning intentions into fast, controlled route implementations. The PBB-TE control plane receives provisioning information from VPLS and implements it with full service provider control over the actual routes and backup paths, eliminating the loss of control inherent in pure VPLS/MPLS solutions.
3Ease of manufacture
If separate VLANs or service instances are assigned to customers, then L2VPN is created, but complete control over network paths is lost
Solution Approach 1:
The patent segments customer traffic identification (handled by VPLS service instances) from path control (handled by PBB-TE). This allows L2VPNs to be easily created using standard VPLS service instance assignment while PBB-TE maintains complete control over the actual network paths through its dedicated control plane and provisioning interface.
Solution Approach 2:
PBB-TE serves as an intermediary layer that receives service provisioning requests from VPLS and implements them with full path control. This intermediary maintains the ease of L2VPN creation through VPLS while ensuring complete service provider control over network paths through PBB-TE's controlled forwarding plane.
Data Source
AI summary
A Layer 2 Virtual Private Network (L2VPN) system is provided. A Provider Backbone Bridge (PBB) network is provided which comprises a plurality of sites to be connected via a L2VPN. The plurality of sites in the PBB network is connected using a plurality of provider backbone trunks that includes a Provider Backbone Transport (PBT) trunk or a Provider Backbone Bridge Traffic Engineering (PBB-TE) trunk, such that the L2VPN includes the plurality of sites.