On the growth of Internet application flows: A complex network perspective

Internet structure possesses many properties of complex networks. However, existing studies are often constrained to deriving web connections based on partial data collected, and the actual Internet traffic and user behaviors are far from being understood. With detailed traffic flow records collected through powerful hardware-based monitors, we study from the perspective of complex network the characteristics of four types of traffic: P2Pdownload, HTTP, Instant Messaging and overall traffic. Based on the data analysis and comparison of different applications, we confirm that both the distributions of node degree and strength of nodes/edges follow power law but they have significant different exponents. Specifically, taking advantage of the strict timing of the records, we study the dynamics of flow graphs. The growth of edges upon nodes is nonlinear. Edges formed between existing nodes, instead of the ones arriving with new nodes dominate the growth. We also observe linear preferential attachment behaviors in the flow graphs.