A Survey of Multicast Network Simulator

A network simulator is a tool that enables users to design, test, and analyze computer networks without having to use physical hardware. They are widely used in various fields such as education, research, network planning, and troubleshooting. This paper discusses two main types of simulators: commercial (like OPNET, QualNet, NetSim), which offer strong support and documentation, and open-source (like NS2, NS3, OMNeT++, J-Sim), which are free and customizable. Simulators include components such as virtual devices, protocols, topologies, and traffic models, and use methods like discrete event or real-time simulation. Popular simulators such as NS-3, OMNeT++, Cisco Packet Tracer, GNS3, and Mininet each serve specific purposes in network testing. Although simulators offer advantages such as cost efficiency, flexibility, and scalability, they also are complicated, require significant hardware, and cannot support newer technologies.