P4STA: High Performance Packet Timestamping with Programmable Packet Processors

QoS requirements of current network control and management applications require the ability to conduct precise measurements of network elements, including switches, routers and Virtual Network Functions (VNFs). State-of-the-art network switches have a forwarding delay of 1µs and below and offer high bandwidths of hundreds Gigabits per second. This imposes high time accuracy and loss-detection requirements on measurement equipment that are not met by existing, software-based measurement tools. The use of specialized tools, meeting these requirements, is restricted by limited flexibility and high cost.In this work, we introduce P4STA, an open source frame-work that combines the flexibility of software-based traffic load generation with the accuracy of hardware packet timestamping. Our evaluation results, obtained using an off-the-shelf P4-programmable switch, show that a time resolution up to 1ns can be achieved on these programmable data plane platforms. Moreover we show how to combine the traffic load of multiple software-based load generators to achieve a measurement load of up to 100Gbit/s per port. Experiments on further programmable platforms, specifically on P4-SmartNICs and FPGAs, show similar results. With this work, we make P4STA available for the research community to advance high performance experiment measurements at nanosecond accuracy.