Chassis Controllers for Network Control Plane Segmentation

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Solution Overview

Problem

Current network management systems face challenges in achieving scalability, mobility, and multi-tenancy due to the complexity of managing large networks with shared switching elements, where user isolation and network mobility are often compromised.

Innovation Solution

A network control system that allows multiple logical datapaths to be specified for different users through shared forwarding elements, using a controller architecture that transforms user input into logical and physical control plane data, enabling virtualization and isolation of networks while sharing switching elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple users share the same switching elements to improve resource utilization and scalability, then network scalability and resource efficiency are improved, but user isolation and security are compromised

Engineering Contradiction:
Improvenetwork scalabilityVSAvoiduser isolation
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the control plane by introducing chassis controllers that are specific to each switching element, separating it from the global network controller. This segmentation allows each chassis controller to manage forwarding logic for its associated switching element independently, maintaining user isolation while enabling shared infrastructure. The control plane is divided into hierarchical levels (global controller and chassis-specific controllers) that can operate semi-independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces chassis controllers as intermediary components between the global network controller and the switching elements. These chassis controllers act as mediators that receive high-level policies from the global controller and translate them into specific forwarding rules for individual switching elements, while also providing isolation between different users' forwarding logic on shared infrastructure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If network controllers maintain a centralized view of network state to improve management efficiency, then management efficiency is improved, but controller complexity and single points of failure increase

Engineering Contradiction:
Improvemanagement efficiencyVSAvoidcontroller complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The control plane is segmented into multiple hierarchical levels: a global network controller that maintains overall network state and a view of all switching elements, and chassis-specific controllers that manage individual switching elements. This segmentation distributes control functions, reducing the complexity and single-point-of-failure risk of a completely centralized controller while maintaining management efficiency through coordinated operation at different levels.

Inventive Principle:
Principle #1Segmentation

3Reliability

If forwarding logic is customized for each user to improve security and isolation, then user isolation is improved, but device complexity and configuration difficulty increase

Engineering Contradiction:
Improveuser isolationVSAvoidforwarding logic complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements universal flow entry templates that can be applied across multiple chassis controllers and switching elements. These templates define common forwarding behaviors that can be instantiated with user-specific parameters, allowing the system to maintain customized forwarding logic for each user while using a standardized, manageable structure that reduces overall complexity.

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

4Adaptability or versatility

If virtual machine migration is enabled across L2 domains to improve mobility, then network mobility is improved, but L2 domain scalability is limited

Engineering Contradiction:
Improvenetwork mobilityVSAvoidL2 domain scalability
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent extends mobility beyond traditional L2 domains by implementing flow entry templates that can be propagated across chassis controllers and switching elements in a hierarchical manner. This adds a new dimension to mobility control, allowing virtual machines to migrate across larger network scopes while maintaining isolation and security through the template-based approach, effectively overcoming the L2 domain size limitation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3515022B1Chassis controllers for converting universal flows
Publication Date: 2022.08.17 NICIRA INC
  • EP3515022B1 patent drawingFigure 1
  • EP3515022B1 patent drawingFigure 2~3
  • EP3515022B1 patent drawingFigure 4

AI summary

A network control system for generating physical control plane data for managing first and second managed forwarding elements that implement forwarding operations associated with a first logical datapath set is described. The system includes a first controller instance for converting logical control plane data for the first logical datapath set to universal physical control plane (UPCP) data. The system further includes a second controller instance for converting UPCP data to customized physical control plane (CPCP) data for the first managed forwarding element but not the second managed forwarding element. The system further includes a third controller instance for receiving UPCP data generated by the first controller instance, identifying the second controller instance as the controller instance responsible for generating the CPCP data for the first managed forward element, and supplying the received UPCP data to the second controller instance.