Efficient Consensus Between Multiple Controllers in Software Defined Networks (SDN)
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https://hdl.handle.net/11250/3049169Utgivelsesdato
2022Metadata
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Software Defined Networking (SDN) has emerged as a popular paradigm for managing large scale networks. The traditional single controller architecture has limitations in managing the entire network: it can become a bottleneck when it comes to exchanging large volumes of data and it implies overhead as the number of user increases. Additionally, the single controller acts as a single point of failure because all the forwarding decisions depend directly on the controller. Once the SDN controller or the switches-to-controller links fail, the entire network may collapse. Therefore, scalability, reliability, interoperability, and fault tolerance remain as challenges in centralized network architectures. On the other hand, multiple controller architectures exhibit faster response and a more flexible network structure. Additionally, they can improve scalability and they avoid a single point of failure. In order to synchronize the network state between different controllers, a consensus protocol is required. In this paper, we propose a consensus mechanism, based on the Raft algorithm, which provides a stable, consistent, and efficient network in which all the controllers have the same network state. The proposed mechanism supports high throughput, dynamic view changes, fault tolerance, and controller synchronization. The performance of the proposed mechanism has been experimentally assessed and found to be very satisfactory compared to existing alternatives.