High-Precision Round-Trip Time Measurements in the Internet with HiPerConTracer

Accurately measuring Round-Trip Times (RTT) for Internet communications is important for various research topics, ranging from protocol performance and congestion control to routing and network security. Unix systems, particularly Linux and FreeBSD, provide some features to obtain network packet timing information, but there is a lack of documentation for these. With High-Performance Connectivity Tracer (HiPerConTracer), there is already an open source tool for running large-scale, long-running and high-frequency ICMP Ping and Traceroute measurements. However, it lacks support of high-precision timing. As part of this paper, first the network packet timestamping features of Unix systems are analysed and introduced, to provide the reader with a detailed overview over the available methods, their usage, as well as their limitations. Then, enhancements to HiPerConTracer are presented for adding high-precision timestamping support, as well as a UDP module to also perform UDP Ping and Traceroute measurements. Finally, the newly added features are demonstrated in a proof-of-concept analysis.