A fault-tolerant architecture for internet-of-things based on software-defined networks

One of the most critical challenges of the Internet of Things (IoT) is to provide real-time services. Therefore, to provide a secure, efficient, and stable communication platform in the Internet of Things, emerging architectures such as software-defined networks (SDN) being significant. This paper proposes a comprehensive SDN based fault-tolerant architecture in IoT environments. In the proposed scheme, a mathematical model called Shared Risk Link Group (SRLG) calculates redundant paths as the main and backup non-overlapping paths between network equipment. In addition to the fault tolerance (FT) discussion in the proposed scheme, service quality is considered in the proposed scheme. Putting the percentage of link usage and the rate of link delay in calculating link costs makes it possible to calculate two completely non-overlapping paths. The end-to-end delay and the degree of link congestion are minimal. We compare our proposed scheme with two policies for building routes from source to destination. The simulation results indicate that, while reducing the error recovery time, the proposed method leads to improved services quality parameters such as packet loss, delay, and packet jitter. The results show that in case of a link failure in the network, the recovery time in large scenarios is a maximum of 16 ms, which improved by 20%, compared to the disjoint paths (DP) method. Our Approach can decrease packet loss by approximately 30% compared to the Dijkstra’s algorithm and roughly 24% compared to the DP method. Also, SLRG reduces latency by approximately 36% compared to the Dijkstra’s algorithm and roughly 19% compared to the DP method. Last, the proposed scheme reduces Jitter by approximately 49% compared to the Dijkstra’s algorithm, and roughly 26% compared to the DP method.