Contribution of the application, transport and network layers to the self-similarity of Internet traffic

There have been few studies evaluating the dominant factor responsible for generating self-similar network traffic while many researchers have discussed the causes of self-similarity. In this paper, we have isolated and compared the effects of the application, transport and network layers on the self-similarity of TCP flows and their aggregates. With a simple computer simulation scenario, we show that in networks where congestion frequently occurs the transport layer dominates the self-similarity of single TCP flows over the application layer. Next we focus on the interactions between the transport and network layer. We show that on high packet loss rates the exponential backoff technique of the TCP is responsible for the elevated level of self-similarity while on low packet loss rates, the synchronization between the TCP flows may induce high degree of self-similarity of the aggregated TCP sessions. To support this conjecture on synchronization, we show synchronization is only present when the TCP flows of the the aggregate operate mostly in congestion avoidance mode.