An SDN-based Network Architecture for Internet of Things

Abstract

The exponential growth of devices connected to the network has resulted in the development of new IoT applications and services. A large number of IoT devices are application-specific which makes the network difficult to manage and change. The Software Defined Networking (SDN) paradigm brings a new perspective of solving the network rigidity issue. By introducing the OpenFlow protocol to the IoT network, the routing decisions can be translated into matching rules and actions in a programmable way, thus simplifying the network configuration and management. However, different from the wired domain, which uses a separate dedicated network for OpenFlow channel, the IoT devices have to communicate with the Controller in a multi-hop way. Since some IoT nodes are unstable due to the limited energy, environment or other factors, the multi-hop way results in an unstable control channel, which degrades the network performance. To address this problem, in this paper, we present a practical SDN-based network architecture for Internet of things. We propose an Optimal Control Channel (OCC) policy to select minimum number of nodes to establish a stable OpenFlow channel to reduce the performance loss caused by unstable IoT nodes. OCC establishes a stable control channel to bridge the IoT nodes and the Controller. Meanwhile, OCC is responsible for the control messages aggregation to further decrease the SDN-inherent control overheads. The experimental results show our architecture outperforms the original SDN-based scheme in terms of control overheads.