Precise One-way Delay Measurement with Common Hardware and Software

5G networks can deliver single-digit millisecond latencies. Equipment used for latency measurement therefore requires to provide sub-millisecond precision. It is a challenge to achieve such accuracy with non-real-time PC operating systems (OS) and common programming languages. Due to this, precise delay measurement solutions often require some degree of hardware support, for example hardware timestamping in the network interface or adjustments to the OS. Additionally, synchronized clocks on sender and receiver are needed to determine one-way-delays and not just round-trip-times. In this paper we present a setup with standard PC hardware, unmodified Linux OS and a free open-source software, capable of performing precise 5G one-way-delay measurements. The same PC can be used as sender and receiver, making synchronized clocks obsolete. When implementing the measurement software, we put extra caution on assuring best-possible timing accuracy despite running on a non-real-time OS. Presented results confirm that our measurement setup and software provide a suitable and easy-to-use toolset for 5G delay performance evaluation, especially for the sake of detecting unexpected network, end-device or application software behavior.