Flow-based analysis of Internet traffic

We propose flow-based analysis to estimate quality of an Internet connection. Using results from the queuing theory we compare two expressions for backbone traffic that have different scopes of applicability. A curve that shows dependence of utilization of a link on a number of active flows in it describes different states of the network. We propose a methodology for plotting such a curve using data received from a Cisco router by NetFlow protocol, determining the working area and the overloading point of the network. Our test is an easy way to find a moment for upgrading the backbone.