A study of precision of hardware time stamping packet traces

Many standards and techniques for time synchronization have emerged in recent years. One of the applications is accurate time stamping of packet traces. However, limited attention was paid to evaluation of the precision of such time stamping. In this paper we study the accuracy of hardware and software timestamps by exploiting Linux and libpcap, and different types of NICs. Our study verifies that hardware timestamps are much more accurate than software timestamps, shows that higher-end NICs provide better timestamps, and indicates that traffic load can affect the accuracy of timestamps.