An SDN Switch Implementation on Cost-Effective IoT Device <Abstract> Software-Defined Networking (SDN) has recently been gaining more popularity since SDN can provide flexibility and efficiency to networks, such as 5G. A basic component in SDN is an SDN switch, which can be realized by two primary methods: simulator or actual implementations. Compared with simulation tools, the latter has the advantages of fidelity and accuracy. However, the existing SDN switches are vendor-specific and expensive, which may affect SDNfs research and innovation paces. This paper presents a method to make a cost-effective SDN switch on an IoT device (i.e., a Raspberry Pi 4 node). We have used OpenvSwitch and additional Ethernet ports to realize the SDN switch. The switch can work in collaboration with an SDN controller and provide numerous forwarding policies. As an example, we implement several forwarding policies with and without VLAN tags on the switch. We have then evaluated the switch performance in the network with two hosts following the policies. The results show that the host-to-host bandwidth (around 95.5 Mbps) is not affected by the policies. Meanwhile, without VLAN, the round-trip time (RTT) value (0.854 ms) is smaller than the one with VLAN (1.051 ms). |