Formullar: An FPGA-based network testing tool for flexible and precise measurement of ultra-low latency networking systems
Abstract As network systems become widespread in emerging time-sensitive domains, latency becomes an important performance factor. Thus, there is a new demand for ultra-low latency (ULL), which requires an extra-ordinarily low latency even in a deterministic manner. To support the ULL requirement, it is mandatory that each network device strictly guarantees this latency. As a result, there is an increasing demand for a precise latency measurement tool that achieves two conflicting goals: high time precision and flexible traffic control. To support these goals, this paper proposes a novel measurement tool, named Formullar , which has a hybrid architecture composed of hardware ( Formullar FPGA) and software ( Formullar controller) layers. Formullar generates packets in an accurate timing, according to the various traffic patterns. The packet generation is controlled in a fully programmable manner that makes the testing fully automated and flexible. Then, latency is measured based on packet generation and reception timing; the measurement is done by the hardware layer, providing highly precise measurement results. Using this carefully constructed system, a Formullar prototype was implemented on top of the commodity FPGA board NetFPGA-SUME. The evaluation indicates that Formullar provides highly precise measurements with nanoseconds precision at a bandwidth of 10 Gbps.