A NetFPGA-based network monitoring system with multi-layer timestamping: Rnetprobe

In this work, we are about to introduce a high performance NetFPGA based network measurement system, called Rnetprobe that implements a dual, multi-layer timestamping method for QoS analysis. The multi-layer timestamping idea came from the demand to perform end-to-end active measurements that enable improved cross-layer analysis to evaluate QoS for time sensitive services. Accordingly, for each captured packet one timestamp is generated at MAC level, which is provided by our FPGA hardware module, while another timestamp is tagged to the packet on its processing path as soon as it becomes available to the OS kernel's network stack. This second timestamp is software based and therefore reflects to the packet processing characteristics of the OS kernel. In this paper, we are introducing the mentioned multi-layer timestamping method and are evaluating its performance.