Multi-Controller SDN Placement for Control Traffic Delay Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current software-defined networks (SDNs) face challenges in efficiently managing control traffic due to the limitations of single controllers, which impact network performance and scalability, particularly in 5G communication networks, where control decisions and flow tables are decentralized, leading to inefficiencies in control message delivery and network resource utilization.
Innovation Solution
The method involves determining the optimal number and placement of multiple controllers in an SDN to minimize control traffic delay by formulating a nonlinear multi-objective optimization problem, partitioning it into sub-problems for multi-controller placement and control traffic balancing, and using an alternating direction method of multipliers (ADMM) for efficient solution approximation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single controller is used in SDN, then the system structure is simple, but the control traffic delay increases and network scalability is limited
Solution Approach 1:
The patent divides the single centralized controller into multiple distributed controllers. Each controller is assigned to manage a specific subset of switches, segmenting the control plane. This segmentation reduces the control traffic load on each individual controller and decreases overall control traffic delay, while maintaining manageable system complexity through modular architecture.
Solution Approach 2:
The patent transitions from a single-point (1D) controller architecture to a multi-point distributed architecture, adding spatial distribution as a new dimension. Controllers are placed at different network locations and interconnected, creating a hierarchical and distributed control plane that reduces traffic delay through parallel processing and localized control decisions.
2Loss of time
If multiple controllers are deployed, then control traffic delay is reduced, but the system complexity increases
Solution Approach 1:
The patent designs controllers with universal functionality, where each controller can perform the same set of control operations and manage different subsets of switches. This multi-functionality allows controllers to be deployed in various configurations and locations without increasing individual controller complexity, as they all follow the same operational framework.
Solution Approach 2:
The patent introduces a controller interconnection mechanism that acts as an intermediary layer between multiple controllers and the data plane. This intermediary structure manages the complexity of multi-controller coordination by providing standardized communication protocols and coordination mechanisms, allowing controllers to work together without requiring complex point-to-point management.
3Ease of operation
If control traffic is concentrated through a single controller, then the control plane is simple to manage, but network resource utilization is inefficient
Solution Approach 1:
The patent segments the control traffic flow by assigning different switch subsets to different controllers. This segmentation distributes control traffic across multiple processing paths, improving network resource utilization by preventing any single controller from becoming a bottleneck, while maintaining ease of operation through systematic traffic distribution rules.
Solution Approach 2:
The patent implements local quality by allowing different controllers to handle different regional or functional subsets of the network. Each controller optimizes control traffic handling for its assigned switches, improving overall network resource utilization through localized control decisions that reduce cross-network traffic and latency.
Data Source
AI summary
A method includes determining a number and placement of multiple controllers in a software defined network (SDN) such that each controller controls a different set of software controlled switches in the SDN and finding optimal forwarding paths for control traffic between the switches and controllers to minimize delay of control traffic over the software defined network.