Abstract: This context represents with network simulation with tools. The network simulation tools are a modern technology. The simulator helps the user to develop the networks with real time. It is useful to test new networking protocols or changes in the existing protocols. The network simulator have different type of tools such as OPNET, QualNet, NS2, Ns3, OMNET++,NetSim, REAL, J-sim, GloMosim.In this article represent with type of network simulator, advantages and disadvantages , and basic architecture of network simulator tools. It is easy to understand for the users.

Keywords: Opnet, Qualnet, Ns2, Ns3, Omnet++, Netsim, J-sim, Glomosim.