Fast Convergence for MAC Mobility in EVPN

Solution Overview

Problem

In Ethernet virtual private networks (EVPN), the propagation of routing information updates across provider edge devices can be slow due to reliance on the control plane, leading to packet drops and increased network congestion when devices move between PE devices, affecting quality of service.

Innovation Solution

Implementing a fast convergence process by transmitting updated routing information via the data plane, allowing other PE devices to forward packets based on new routing information without waiting for withdrawal messages from the control plane, thereby reducing convergence time and minimizing packet drops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If routing information updates are propagated via the control plane, then routing information is updated across PE devices, but the propagation speed is slow causing packet drops and network congestion

Engineering Contradiction:

Improverouting information propagation speedVSAvoidpacket delivery reliability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent introduces a mobility message as an intermediary carrier to transport routing information between PE devices. This mobility message is specifically designed to convey MAC address mobility information and is processed through a dedicated mobility message processing mechanism, enabling faster and more reliable routing updates compared to traditional control plane propagation

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements preliminary action by pre-establishing mobility message processing capabilities and routing information update mechanisms before device mobility events occur. PE devices are pre-configured to recognize and process mobility messages, and routing information structures are prepared in advance to accommodate rapid updates, enabling immediate response when device mobility is detected

Inventive Principle:

Principle #10Preliminary action

2Productivity

If PE devices wait for withdrawal messages from the control plane before forwarding packets, then routing information consistency is maintained, but convergence time increases and productivity decreases

Engineering Contradiction:

Improvenetwork convergence speedVSAvoidrouting information consistency

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent implements preliminary action by pre-establishing mobility message processing capabilities and routing information update mechanisms before device mobility events occur. PE devices are pre-configured to recognize and process mobility messages, and routing information structures are prepared in advance to accommodate rapid updates, enabling immediate response when device mobility is detected

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces dynamic routing information update mechanisms that allow PE devices to adaptively adjust their forwarding behavior based on received mobility messages. The system transitions from static waiting for control plane updates to dynamic real-time updates, where routing information can be immediately modified upon receiving mobility messages, enabling rapid convergence while maintaining consistency through structured update propagation

Inventive Principle:

Principle #15Dynamics

3Reliability

If traditional control plane updates are used for device mobility, then routing information is eventually updated, but packet drops occur and network resources are wasted during the convergence period

Engineering Contradiction:

Improvepacket delivery reliabilityVSAvoidconvergence time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent introduces a mobility message as an intermediary carrier to transport routing information between PE devices. This mobility message is specifically designed to convey MAC address mobility information and is processed through a dedicated mobility message processing mechanism, enabling faster and more reliable routing updates compared to traditional control plane propagation

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements preliminary action by pre-establishing mobility message processing capabilities and routing information update mechanisms before device mobility events occur. PE devices are pre-configured to recognize and process mobility messages, and routing information structures are prepared in advance to accommodate rapid updates, enabling immediate response when device mobility is detected

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12021657B1Fast convergence for MAC mobility

Publication Date: 2024.06.25 JUNIPER NETWORKS INC

AI summary

A first provider edge device may receive device information from a second provider edge device included in an Ethernet virtual private network (EVPN). The device information may identify a media access control (MAC) address and may indicate that the device is connected to the second provider edge device. The first provider edge device may receive data transmitted by the device and may determine, based on information included in the data, that the device has moved from the second provider edge device to the first provider edge device. The first provider edge device may generate a data packet including mobility information indicating that the device has moved to the first provider edge device. The first provider edge device may transmit, via a data plane of the EVPN, the data packet to the second provider edge device to permit the second provider edge device to update routing information for the device.