Out of order packets analysis on a real network environment

As Internet usage grows, more efforts are put in analysing its internal performance, usually such analysis comes through simulation using different models. While simulation can provide a good approximation of network behaviour, modeling such a complex network as the Internet is very difficult if not impossible. This paper studies the network's performance from an experimental point of view using the European Academic Network (EAN) as a testbed. In the framework of the EuQoS project, many performance tests have been performed to prove the reliability of data transmissions. The tests show some rough edges which need further analysis, among them the most important being random losses in UDP flows and a great amount of out of order packets. This paper focuses on the study of such out of order packets, searching for their causes, and more importantly to show the effects on real-time traffic such as VoIP, videoconferencing, video streaming, etc