Ensuring Reliable OpenFlow Channel for SDN Based Cyber-Physical System
Hyeontae Joo, Hwangnam Kim · 2021 21st International Conference on Control, Automation and Systems (ICCAS) · 2021
Software-Defined Networking (SDN) is a network architecture approach that enables intelligent and centralized control or programming of networks through software applications. Since SDN enables traffic management and flexible network configuration through SDN application programming interfaces (APIs) to effectively transmit data over the most appropriate path, Cyber Physical System (CPS) employs SDN to construct feedback loops between physical processes and computations. However, when OpenFlow channel connecting the two representative components of SDN, the SDN controller and the switch, is configured over a wireless network, it often falls into a bad state, which can lead to uncertainty in transmitting the necessary network state data. In this paper, we applied Multipath TCP (MPTCP) rather than Transport Control Protocol (TCP) to the unstable wireless OpenFlow channel to improve the uncertainty about the transmission failure rate. We confirmed that the OpenFlow channel has high reliability by applying various schedulers for MPTCP. By applying the proposed method, we observed an improvement in data transmission from 64% up to 173% compared to the single TCP connection case when the transmission failure rate was up to 28%.