Modeling the interaction between the SDN controller and the network infrastructure

Abstract

Flexible network architecture will likely be required to adapt due to the recent growth of network computing. Software-Defined Networking (SDN) is a new paradigm that simplifies the organization of data communications, facilitates the evolution of computer networking, and paves the way to absorb the potential requirements of future network changes. SDN aims to decouple the control function from the end network devices (i.e., routers) and provide an external centralized entity for all the network's control activities. However, the SDN's control capabilities are limited to the performance of a single controller, which requires further consideration. Our research aims to investigate the current state of SDN research and provide possible solutions addressing SDN's control limitations. To improve network performance, we introduce several models that aim to address the interaction between the SDN controller and the end network devices. The contribution of this research involves the introduction of assistant switches, edge controllers, and self-routing traffic flows to alleviate the controller's burden and improve its processing efficiency. To demonstrate the effectiveness of the proposed techniques, we implemented a simulated SDN-based network with one controller connected to 32 switches that carry and route traffic flows among multiple end-hosts. The results of the experimental studies show a significant improvement in the controlling performance, including more than 30% decrease in controller effort, a 45% decrease in bandwidth usage, and up to a 29% decrease in controller response time.