Testing Internet applications and services using PlanetLab

In this paper we evaluate a commonly used testing tool of Internet applications and services - PlanetLab. PlanetLab is a large-scale network of Linux servers used for Internet development and research. The geographical diversity of the servers allows engineers and researchers to test networking applications in the real Internet worldwide. In the paper we evaluate PlanetLab from different points of view we identified based on its long-term use. We specifically deal with the problematic aspects, such as PlanetLab service availability, networking performance, geographical accuracy, and DNS addressing correctness. Some of the PlanetLab 'negative' properties evaluated in this paper are required and needed as PlanetLab was established to reflect the real (erroneous) communication in the Internet. Nevertheless, one should be aware of them to set-up experiments correctly, run them smoothly, and not to misinterpret the results. Based on the observations presented, we give a set of simple conclusions that should help engineers to achieve valid Internet experiment results.