In large-scale networks, end-systems cannot rely on the network itself to cooperate in characterizing its own behavior. It is also impossible to set up internal monitors at all routers in the Internet due to cost and deployment problems. In general, taking measurements at the edge of a network is a much easier and inexpensive proposition than performing internal monitoring. This has prompted us to study the so-called Network Tomography problem.
To present methodology for network tomography based on passive monitoring of unicast traffic. Parameters such as link loss rates, delay statistics and topology inference will be modeled and its performance will be evaluated with realistic network simulations (Network Simulator, ns-2).