An Experimental Study of the Skype Peer-to-Peer VoIP System

Overview

Despite its popularity, relatively little is known about the traffic characteristics of the Skype VoIP system and how they differ from other P2P systems. The paper describes an experimental study of Skype VoIP traffic conducted over a five month period, where over 82 million datapoints were collected regarding the population of online clients, the number of supernodes, and their traffic characteristics. This data was collected from September 1, 2005 to January 14, 2006. Experiments on this data were done in a black­-box manner, i.e., without knowing the internals or specifics of the Skype system or messages, as Skype encrypts all user traffic and signaling traffic payloads.