  An important challenge for smart grid security is designing a secure and
robust smart grid communications architecture to protect against cyber-threats,
such as Denial-of-Service (DoS) attacks, that can adversely impact the
operation of the power grid. Researchers have proposed using Software Defined
Network frameworks to enhance cybersecurity of the smart grid, but there is a
lack of benchmarking and comparative analyses among the many techniques. In
this work, a distributed three-controller software-defined networking (D3-SDN)
architecture, benchmarking and comparative analysis with other techniques is
presented. The selected distributed flat SDN architecture divides the network
horizontally into multiple areas or clusters, where each cluster is handled by
a single Open Network Operating System (ONOS) controller. A case study using
the IEEE 118-bus system is provided to compare the performance of the presented
ONOS-managed D3-SDN, against the POX controller. In addition, the proposed
architecture outperforms a single SDN controller framework by a tenfold
increase in throughput; a reduction in latency of $>20\%$; and an increase in
throughput of approximately $11\%$ during the DoS attack scenarios.
