This is work in progress!

Introduction

ns-3 is a discrete-event network simulator for Internet systems, targeted primarily for research and educational use. [...] The goal of the ns-3 project is to develop a preferred, open simulation environment for networking research: it should be aligned with the simulation needs of modern networking research and should encourage community contribution, peer review, and validation of the software.

-- From the ns-3 documentation

This project benefits on ns-3 being a discrete-event simulator because it simplifies logging and debugging in distributed systems and can reduce simulation time compared to real time simulators. ns-3 is not a physics simulation but it is able to do continuous/real time simulation so it can be used in combination with other simulators.

The simulator is used for modular testing and verification of SOLA, MINHTON, NATTER and OptiMaFlow as well as for holistic simulation of those applications.