DEVS-RPL: Design Formal Discrete Event Model of Routing Protocol over LLN

The Internet of Things is rapidly advancing, enabling interactions with the physical world and presenting various applications. Routing Protocol over Low-Power and Lossy Networks (RPL) is the routing protocol introduced by the IETF for IoT environments. RPL has been subjected to multiple attacks, making it essential to develop a model that defines its behavior. To achieve this, we propose DEVS-RPL, which employs the discrete event model to specify the normal behavior of network nodes in generating RPL messages. DEVS-RPL estimates the mean and frequency of each generated RPL message by defining the participant states and utilizing the time advance function. As a proof of concept, the normal network traffic produced by the Cooja simulator is compared to the RPL messages generated by the DEVS-RPL model. We find that the mean absolute percentage error (MAPE) of DEVS-RPL is less than 9%, indicating the high accuracy of the proposed model.