Virtual Chassis Pass-Thru Mode for Network Resilience

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Solution Overview

Problem

Existing data networks face challenges in maintaining high availability and network resiliency due to difficulties in upgrading or transitioning between different node architectures and topologies, which affects the ability to handle component and link failures effectively.

Innovation Solution

A virtual chassis system is introduced, comprising network nodes that operate as a single logical device with unified management, using virtual fabric links for communication and load balancing, allowing for seamless transition to alternate paths in case of failures, and supporting various network topologies through a network topology discovery process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If network nodes are implemented with fixed node architectures (single switching elements, stackable switching elements, or multi-slot chassis based network elements), then device stability and ease of manufacture are improved, but adaptability and ease of upgrading between different node architectures deteriorate

Engineering Contradiction:
Improvedevice stabilityVSAvoidadaptability between node architectures
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent implements a universal control plane that can manage multiple types of node architectures (single switching elements, stackable switching elements, and multi-slot chassis based network elements) through a common interface and protocol. This allows the network to maintain stability with fixed architectural types while gaining adaptability to transition between them, as the control plane can orchestrate upgrades and changes without requiring architecture-specific management systems

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If redundant nodes and multiple physical paths are implemented to achieve network resiliency, then reliability is improved, but device complexity and loss of time for detection and convergence increase

Engineering Contradiction:
Improvenetwork resiliencyVSAvoidtopological complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the control plane continuously monitors the network topology and node states, and automatically adjusts traffic routing when failures are detected. This feedback loop enables the system to maintain high reliability through redundant paths while reducing the perceived complexity, as the feedback-driven automation handles the complexity of managing multiple paths and failure scenarios without requiring manual intervention

Inventive Principle:
Principle #23Feedback

3Reliability

If detection and convergence times are reduced to achieve seamless transition to alternate paths, then network resiliency is improved, but device complexity and processing requirements increase

Engineering Contradiction:
Improvenetwork resiliencyVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements preliminary action by pre-computing alternate paths and routing configurations before failures occur. The control plane maintains a database of pre-calculated backup routes and can immediately activate them when failures are detected, thereby achieving fast convergence times without the processing complexity of real-time path computation during failure events

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If multiple types of node architectures are supported within one network, then adaptability is improved, but ease of operation and management difficulty increase

Engineering Contradiction:
Improvesupport for multiple node architecturesVSAvoidease of management
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent introduces a control plane as an intermediary layer between the network manager and the diverse node architectures. This intermediary translates high-level management commands into architecture-specific configurations, allowing the network to support multiple node types while maintaining ease of operation through a unified management interface that abstracts away the complexities of different architectures

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2918054B1System and method for a pass thru mode in a virtual chassis system
Publication Date: 2019.08.21 ALCATEL LUCENT SA
  • EP2918054B1 patent drawingFigure 1a
  • EP2918054B1 patent drawingFigure 1b~1c
  • EP2918054B1 patent drawingFigure 2~3

AI summary

A virtual chassis system includes a plurality of network nodes connected by virtual fabric link (VFLs) that provide a connection for exchange of packets between the network nodes. A network node in the virtual chassis system is operable in a pass thru mode. In pass thru mode, the network node receives packets over a VFL and transparently forwards the packet over another VFL to another network node in the virtual chassis system. However, the network node 110 disables other port interfaces, such as port interfaces connected to external nodes from the virtual chassis system. The network node 110 in pass thru mode is operable to receive management commands over one or more VFLs and can still be managed through management commands.