Assessing the overhead of authentication during SDN-enabled restoration of smart grid inter-substation communications

Abstract

Since real-time and resilient recovery of link failures is crucial for power grid infrastructure to continue its services, emerging technologies such as Software Defined Networking (SDN) has started to be employed for such purposes. SDN switches can be remotely controlled to change their configurations by exploiting the wireless communication options. However, when wireless is to be used in Smart Grid communications, security and reliability become important issues due to the specific characteristics of wireless communications. This paper investigates the overhead of providing such services on wireless links when SDN is utilized. Specifically, we consider the establishment of authentication services when wireless back-up links (i.e., WiFi or LTE) are employed as a result of a reactive link failure detection mechanism. To the best of our knowledge, this work is the first to consider authentication of such an SDN-enabled Smart Grid inter-substation communication with WiFi and LTE. To be able to effectively evaluate the performance of this proposed SDNenabled framework, we developed it in Mininet emulator. Since Mininet does not support the authentication services for WiFi or LTE, we proposed several novel extensions to Mininet by integrating it with ns-3 simulator that supports the LTE/WiFi protocol stacks. We conducted extensive experiments by considering a general application using Smart Grid Manufacturing Message Specification (MMS) standard to assess the recovery performance of the proposed secure SDN-enabled recovery system. The results show that when authentication and reliable protocols such as TCP are to be employed, the proposed framework can still meet the deadlines of 100 ms with WiFi while LTE misses only a few packets.