Routing Convergence in Intelligent Optical Network Control Plane

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Solution Overview

Problem

Conventional routing convergence methods in intelligent optical networks are slow, leading to delayed re-routing and potential service failures when link failures occur in the control plane, affecting network survivability.

Innovation Solution

A method and apparatus where a function unit in the transport plane rapidly transmits a service failure alarm to a routing protocol unit, enabling quick confirmation and updating of the routing table in the control plane, allowing for rapid re-routing within seconds or milliseconds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the conventional routing protocol perceives link failure by waiting for timeout of routing messages, then the system can confirm link failures, but the convergence speed is slow (taking tens of seconds)

Engineering Contradiction:
Improvelink failure detection accuracyVSAvoidrouting convergence time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the transport plane proactively send alarm notification messages to the control plane when link failures are detected, rather than waiting for the routing protocol timeout. This advance notification allows the control plane to prepare for and respond to failures much faster, reducing convergence time from tens of seconds to potentially milliseconds while maintaining reliable failure detection

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mechanism where the transport plane acts as a mediator between the physical link and the control plane routing protocol. When a link failure occurs, the transport plane intercepts the failure detection and immediately notifies the control plane through alarm messages, bypassing the slow routing protocol timeout mechanism and enabling faster convergence

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the routing protocol uses timeout-based failure detection, then link failures can be confirmed, but re-routing fails or is delayed when multiple link failures occur simultaneously

Engineering Contradiction:
Improvefailure detection capabilityVSAvoidservice establishment speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

By having the transport plane send proactive alarm notifications upon detecting link failures, the control plane receives advance warning before the routing protocol timeout occurs. This allows the control plane to immediately initiate re-routing calculations and service establishment procedures, dramatically improving service establishment speed while maintaining reliable failure detection through the alarm mechanism

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by establishing a direct communication channel from the transport plane to the control plane. When the transport plane detects a link failure, it immediately feeds this information back to the control plane through alarm notification messages, enabling the control plane to respond in real-time rather than waiting for the slow routing protocol feedback loop

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP1881728B1Method and apparatus of routing convergence in control plane of an intelligent optical network
Publication Date: 2014.08.06 HUAWEI TECH CO LTD
  • EP1881728B1 patent drawingFigure 1~2
  • EP1881728B1 patent drawingFigure 3~4
  • EP1881728B1 patent drawingFigure 5

AI summary

The embodiments of the present invention provide a method of routing convergence in a control plane of an intelligent optical network, which includes: a function unit perceiving a service link state transmitting an alarm notification message indicating a failure in a service link to a routing protocol unit when the service link is in failure; the routing protocol unit confirming a service link failure in the control plane according to the alarm notification message. The embodiments of the present invention also provide an apparatus of routing convergence in a control plane of an intelligent optical network. According to the embodiments of the present invention, the establishment of a new service or re-routing may be implemented within several seconds or even hundreds of milliseconds after the service link failure in the control plane occurs.