MPLS Reverse Notification Tree for Rapid Fault Recovery

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Solution Overview

Problem

MPLS networks face significant delays in recovering from link or switch failures, taking several seconds to several minutes, which is unacceptably long and affects network reliability.

Innovation Solution

Implementing a reverse-directed status message system that sends upstream notifications through a pre-determined pathway, allowing upstream switching systems to detect downstream failures and promptly reroute data through a pre-established protection path, minimizing data loss and recovery time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional fault recovery mechanisms are used in MPLS networks, then network reliability is maintained, but fault recovery time is unacceptably long (several seconds to several minutes)

Engineering Contradiction:

Improvenetwork reliabilityVSAvoidfault recovery time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent establishes protection pathways and pre-configures rerouting information before failures occur. When a failure is detected through the reverse notification tree, the network can immediately switch to the pre-established protection path without needing to calculate a new route, reducing recovery time from seconds/minutes to hundreds of milliseconds

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements a reverse notification tree that continuously monitors the health of downstream switches and sends status messages upstream. When a failure is detected, this feedback mechanism immediately triggers the protection switching mechanism, enabling rapid response to failures and maintaining network reliability

Inventive Principle:

Principle #23Feedback

2Adaptability or versatility

If dynamic alternate protection paths are calculated upon failure, then adaptability is improved, but recovery time increases due to calculation requirements

Engineering Contradiction:

Improvepath rerouting adaptabilityVSAvoidrecovery time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent pre-calculates and stores multiple protection paths along with their associated routing information in the reverse notification tree structure. When a failure occurs, the system selects from pre-computed alternatives rather than performing dynamic calculations, maintaining adaptability while reducing recovery time to hundreds of milliseconds

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent enables dynamic selection among multiple pre-established protection paths based on current network conditions. The system can adaptively choose the most appropriate protection path from available options, maintaining versatility while avoiding the time cost of dynamic path calculation

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS7796504B1Method for establishing an MPLS data network protection pathway

Publication Date: 2010.09.14 TELLABS OPERATIONS

AI summary

Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to upstream switching system that the downstream traffic arrived in tact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway. The reverse notification pathway is established by using a messaging protocol between network switches by which the working and protection paths, among other things, are established.