DHT-Based SDN Controller Network Scalability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Centralized network controllers in SDN architectures face scalability issues, leading to increased time delays, limited throughput, and high maintenance costs due to complex interactions between multiple network controllers and switches during path establishment processes.

Innovation Solution

A DHT-based control network implementation method and system that establishes reliable routing control channels between switches and network controllers using a distributed algorithm, allowing switches to generate IDs and network controllers to communicate through a distributed routing protocol, thereby simplifying path creation and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a centralized network controller is deployed to manage all switches, then control simplicity is maintained, but network scalability deteriorates and time delay increases

Engineering Contradiction:
Improvecontrol plane complexityVSAvoidnetwork scalability
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent segments the centralized control plane into multiple distributed network controllers, each managing a subset of switches. This segmentation resolves the contradiction by distributing control functions across multiple nodes, thereby maintaining control simplicity through modular design while significantly improving network scalability and reducing time delays for flow establishment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension of spatial distribution by deploying network controllers across multiple physical locations and network domains. This dimensional transformation allows the system to scale horizontally across the network topology, converting a single-point bottleneck into a distributed architecture that improves scalability without sacrificing control manageability.

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

2Productivity

If multiple network controllers are deployed to improve scalability, then network scalability is improved, but maintenance complexity increases

Engineering Contradiction:
Improvenetwork scalabilityVSAvoidcontrol plane complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements universal controller modules with standardized interfaces and protocols that can be deployed across multiple network controllers. Each controller instance provides the same set of functions and manages switches through consistent mechanisms, allowing the system to scale while maintaining uniform maintenance procedures and reducing operational complexity despite the increased number of controllers.

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

3Adaptability or versatility

If flow table transmission involves multiple network controllers and switches, then path establishment capability is improved, but interaction complexity increases

Engineering Contradiction:
Improvepath establishment capabilityVSAvoidinteraction complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces intermediary components such as a global routing table and standardized message protocols that mediate between multiple network controllers and switches. These intermediaries coordinate flow table transmissions and path establishment requests across the distributed controller architecture, enabling complex path establishment capabilities while reducing direct interaction complexity between individual controllers and switches.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2933979B1DHT-based control network implementation method and system, and network controller
Publication Date: 2019.01.16 ZTE CORP
  • EP2933979B1 patent drawingFigure 1
  • EP2933979B1 patent drawingFigure 2
  • EP2933979B1 patent drawingFigure 3(a)~3(b)

AI summary

The disclosure discloses a Distributed Hash Table (DHT)-based control network implementation method and system. The method includes that: switches establish routing control channels with specified network controllers in a distributed Peer-to-Peer (P2P) network; head-node network controllers generate P2P path creation request messages, and forward the P2P path creation request messages along paths until the P2P path creation request messages reach end-node network controllers; each network controller on the paths transmits forwarding flow tables contained in the P2P path creation request messages to the switches managed by themselves to finish respective local path creation according to the P2P path creation request messages; and the head-node network controllers determine whether the paths are successfully created or not in combination with local path creation results according to received P2P path creation responses. The disclosure further discloses a network controller. By the disclosure, a network controller network is self-organized, and is automatically accessed by the switches, and meanwhile, calculation and transmission of the network paths are easy to manage.