Computers

Ns is a discrete event simulator targeted at networking research. Ns provides substantial support for simulation of TCP, routing, and multicast protocols over wired and wireless (local and satellite) networks.

OMNeT++ is an open-source, component-based simulation package built on C++ foundations. It offers a C++ simulation class library and GUI support (graphical network editing, animation).

a modular network simulator featuring a java GUI

Network simulator designed from the outset for maximum speed and scalability, with real-time simulation as an achievable goal.