Network Traffic Modeling

From the viewpoint of a service provider, demands on the network are not entirely predictable. Traffic modeling is the problem of representing our understanding of dynamic demands by stochastic processes. Accurate traffic models are necessary for service providers to properly maintain quality of service. Many traffic models have been developed based on traffic measurement data. This chapter gives an overview of a number of common continuous-time and discrete-time traffic models. Sources are sometimes policed or regulated at the network access, usually by a leaky-bucket algorithm. Access policing can change the shape of source traffic by limiting the peak rate or burstiness. Source traffic may also be regulated by protocol mechanisms such as sliding windows or congestion windows (as in TCP), leading to other traffic models. INTRODUCTION Teletraffic theory is the application of mathematics to the measurement, modeling, and control of traffic in telecommunications networks (Willinger and Paxson, 1998). The aim of traffic modeling is to find stochastic processes to represent the behavior of traffic. Working at the Copenhagen Telephone Company in the 1910s, A. K. Erlang famously characterized telephone traffic at the call level by certain probability distributions for arrivals of new calls and their holding times. Erlang applied the traffic models to estimate the telephone switch capacity needed