A Comparative Study of Zynq-Based OpenFlow Switches in a Software/Hardware Co-design

The end-to-end design principle has been re-examined over the years with the increasing number of middle-boxes on the Internet. The newly released Xilinx Zyqn-based chipsets have been reshaping popular embedded computing platforms, which provide cost-effective but all programmable approaches to enable intelligence at the network edge. In this paper, we design and implement a software defined networking (SDN) switch on ONetSwitch based on Zynq series chip. The previous switch implements the software-based switching functions running in the Linux kernel. We added the FPGA hardware structure to the software switch for accelerating packet processing and flow-table matching; therefore some functions of the SDN switch were transformed to FPGA. We constructed an SDN testbed using the re-constructed switch system, the Ryu controller and the client building software to evaluate the performance of the pure software switch and the new switch. We utilized network performance testing tools, such as iPerf and Ping, to evaluate the streaming performance including throughput, delay and delay jitter for these two SDN switches. The experiment results demonstrated the accelerating capability of hardware-based flow-table matching, indicating that the hardware and software co-design method is promising to provide a broad design and optimization space for network systems. As a case study, this switch project demonstrated the design process, verified the hardware platform and the software tool chain to accomplish a hardware/software co-design.