This paper presents a framework for networked control system simulation (NCSS) to enable the analysis of the influence of network transmissions on the performance of control systems. The simulation is composed of the network environment simulated using the network simulator, the control system component simulation using Matlab or C/C++, and an external application programming interface. To implement the plant (sensor), controller, and actuator nodes, an agent-based design is introduced, and a multi-agent networked control system is constructed. Therefore, the network simulator 2-26 (NS-2.26) release is extended by modifying the user data protocol (UDP) common header in order to support application data transmission between network nodes. Then, modifying the network topology parameters, networked control system simulations are analyzed for different parameter changes, such as the network bandwidth, the number of plant nodes, and the sampling period. An analysis of the influence of these parameters on network-induced delays and packet drop is made. The results show that the simulation system is an effective tool for the study of networked control systems.