The extensive growth of peer-to-peer video applications (P2PTV) indicates the evolutionary path towards the next generation of networking. To enhance the quality of experience for P2PTV users, new P2P video traffic models are required. These models are often developed by measurement-driven performance modeling based upon statistical analysis. However, this type of analysis can be a challenging task, due to the complexity and especially, with large sample sizes, the sheer quantity of the data. For this reason, preliminary data examination by graphical means and appropriate visualization techniques can be of great value. In this paper, the versatile network traffic analyzer Atheris will be introduced. It is an essential part of a comprehensive traffic measurement and analysis concept to cope with the rapid deployment of P2PTV applications and their overlay structures. Atheris has been designed specially for measuring P2P applications and for visualizing their inherent properties. As a part of its functionality, Atheris performs traffic measurements at the packet layer, data extraction, flow analysis and enables the visual inspection of statistical characteristics. Furthermore, an evaluation of overlay structures by bandwidth estimation techniques and an overview of the statistical P2P traffic features are provided.