Transparent Recovery of Dynamic States on Constrained Nodes through Deep Packet Inspection

Abstract: Many IoT applications make extensive use of constrained devices which are characterized by unexpected failures. In addition, nodes could be put offline temporarily for maintenance (e.g. battery replacement). These incidents lead to loss of dynamic data that is generated due to the interactions between nodes. For instance, configuration settings adjusted by sending PUT request to the sensor will be lost when the node is rebooted. The lost data, which we call dynamic states, leads to erroneous results or malfunctions of the IoT application. In this paper, we introduce an intelligent dynamic state recovery mechanism through deep packet inspection. A State Directory, placed at the gateway, intercepts every communication between an external device and constrained devices and stores (or updates) information that is important to restore dynamic states. When a node reports a reboot, the state directory replays the packets that generated the dynamic state so that all dynamic states are restored. We implemented the solution on a non-constrained device that acts as a gateway to the constrained network and tested the results using Cooja simulator.