Analysis and modeling of World Wide Web traffic for capacity dimensioning of Internet access lines

A study on traffic characterization of the Internet is essential to design the Internet infrastructure. In this paper, we first characterize WWW (World Wide Web) traffic based on the access log data obtained at four different servers. We find that the document size, the request inter-arrival time and the access frequency of WWW traffic follow heavy-tail distributions. Namely, the document size and the request inter-arrival time follow log-normal distributions, and the access frequency does the Pareto distribution. For the request inter-arrival time, however, an exponential distribution becomes adequate if we are concerned with the busiest hours. Based on our analytic results, we next build an M/G/1/PS queuing model to discuss a design methodology of the Internet access network. The accuracy of our model is validated by comparing with the trace-driven simulation. We also investigate the effect of document caching at the Proxy server on the WWW traffic characteristics. The results show that the traffic volume is actually reduced by the document replacement policies, but the traffic characteristics are not much affected. It suggests that our modeling approach can be applied to the case with document caching, which is demonstrated by simulation experiments.