Simplified Layer 2 VPLS Control Plane with Data-Plane MAC Learning

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Solution Overview

Problem

Existing VPLS technologies face challenges with slow MAC learning and complex control planes, particularly in Ethernet Virtual Private Networks (EVPN), which impact network scalability and convergence speed.

Innovation Solution

A simplified VPLS scheme that uses BGP signaling for data plane MAC learning, employing global IDs and VLAN identifiers to enhance scalability and convergence, while maintaining benefits like multi-active redundancy and auto-discovery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If BGP control plane MAC learning is used in EVPN, then MAC address learning capability is improved, but convergence speed deteriorates and device complexity increases

Engineering Contradiction:

ImproveMAC address learning capabilityVSAvoidconvergence speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent introduces a data plane as an intermediary mechanism for MAC address learning, bypassing the slow control plane BGP signaling. The data plane performs fast MAC learning through direct packet inspection and forwarding decisions, while BGP control plane maintains only the essential VPLS connectivity state. This intermediary data plane learning mechanism resolves the contradiction by providing fast MAC address convergence without requiring control plane protocol changes.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the MAC address learning function from the control plane BGP protocol and places it in the data plane. The control plane handles only VPLS service establishment and connectivity, while the data plane independently performs MAC address learning, forwarding decisions, and flood/unknown unicast/multicast (BUM) traffic handling. This segmentation allows each plane to optimize its function independently, achieving fast MAC convergence without control plane overhead.

Inventive Principle:

Principle #1Segmentation

2Reliability

If BGP control plane MAC learning is used in EVPN, then MAC address learning capability is improved, but device complexity increases

Engineering Contradiction:

ImproveMAC address learning capabilityVSAvoidcontrol plane complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the MAC address learning functionality from the BGP control plane and relocates it to the data plane. The control plane retains only the essential VPLS service establishment, peer discovery, and connectivity state. The data plane independently performs MAC address learning, forwarding table maintenance, and BUM traffic management. This extraction eliminates the complexity of BGP MAC learning state machines, route processing, and control plane software overhead while maintaining reliable MAC address learning capability.

Inventive Principle:

Principle #2Taking out (Extraction)

3Adaptability or versatility

If full mesh VPLS connectivity is established, then multipoint-to-multipoint Ethernet service is improved, but network scalability deteriorates

Engineering Contradiction:

Improvemultipoint-to-multipoint Ethernet serviceVSAvoidnetwork scalability

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent enables the data plane to perform self-service MAC address learning and forwarding decisions without continuous control plane intervention. Each PE router independently learns MAC addresses from incoming packets, maintains local forwarding tables, and makes autonomous forwarding decisions. This self-service mechanism in the data plane eliminates the need for control plane signaling for every MAC address event, dramatically improving scalability while maintaining full mesh VPLS connectivity and multipoint-to-multipoint Ethernet service capability.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS12452168B2Simplification of layer 2 VPLS control plane

Publication Date: 2025.10.21 CIENA CORP

AI summary

A Provider Edge (PE) node is configured to provide a Layer 2 Virtual Private Local Area Network (LAN) service (VPLS) having a simplified control plane. The PE node includes circuitry configured to receive a packet from a second PE node in the network, wherein the packet includes (1) a Destination Media Access Control (MAC) address associated with a destination Customer Edge (CE) node, (2) a source MAC address associated with a source CE node, and (3) a Virtual Local Area Network (VLAN) Identifier used to represent one of the second PE node and a multihome configuration including the second PE node, and learn the source MAC address associated with the source CE node as being reachable via the one of the second PE node and the multihome configuration.