Sherlock: A framework for P2P traffic analyis

After P2P file-sharing and VoIP telephony applications, VoD and live-streaming P2P applications have finally gained a large Internet audience as well. In this work, we define a framework for the comparison of these applications, based on the measurement and analysis of the traffic they generate. In order for the framework to be descriptive for all P2P applications, we first define the observable of interest: such metrics either pertain to different layers of the protocol stack (from network up to the application), or convey cross-layer information (such as the degree of awareness, at overlay layer, of properties characterizing the underlying physical network). The framework is compact (as it allows to represent all the above information at once), general (as is can be extended to consider metrics different from the one reported in this work), and flexible in both space and time (as it allows different levels of spatial aggregation, and also to represent the temporal evolution of the quantities of interest). Based on this framework, we analyze some of the most popular P2P application nowadays, highlighting their main similarities and differences.