HOTS: An OWAMP-Compliant Hardware Packet Timestamp Recorder

Accurate timestamps on both the sender and the receiver side are crucial for one-way delay (OWD) measurements. Traditionally, such measurements use software-based timestamps, which could suffer from errors of up to tens of milliseconds. In this paper, we introduce HOTS-a hardware packet timestamp recorder dedicated to OWD measurements. Compared with traditional methods, HOTS has the advantage of: (i) it can generate extremely precise timestamps for both outgoing and incoming OWAMP test packets, and (ii) it eliminates all kinds of software overheads. We present the results of OWD measurements that we carried out using this timestamp recorder and confirm some basic characteristics of the Internet traffic. In addition, we compare these results with those based on traditional methods of obtaining time information. We show that the results of HOTS are more accurate and stable. Although HOTS is developed for measuring OWD, it can also provide accurate timestamps for other applications