Measuring the Dynamical State of the Internet: Large Scale Network   Tomography via the ETOMIC Infrastructure
  In this paper we show how to go beyond the study of the topological properties of the Internet, by measuring its dynamical state using special active probing techniques and the methods of network tomography. We demonstrate this approach by measuring the key state parameters of Internet paths, the characteristics of queueing delay, in a part of the European Internet. In the paper we describe in detail the ETOMIC measurement platform that was used to conduct the experiments, and the applied method of queueing delay tomography. The main results of the paper are maps showing various spatial structure in the characteristics of queueing delay corresponding to the resolved part of the European Internet. These maps reveal that the average queueing delay of network segments spans more than two orders of magnitude, and that the distribution of this quantity is very well fitted by the log-normal distribution. 
Gabor Simon, Jozsef Steger, Peter Haga Istvan Csabai, Gabor Vattay