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.