Maintaining the quality of network traffic of a control system is crucial; however, this is becoming much more challenging with the emerging IP-based technologies. Operators must constantly monitor the state of traffic flow in the control system and decide whether the system is functioning properly. To achieve this, we must know the characteristics of normal traffic and extract boundary conditions, i.e., thresholds, at which the quality of services begins to deteriorate to intolerable levels; this helps distinguish safe traffic from an undesirable one. The authors propose to use a network simulation technique to analyze the traffic behavior of IP-based control systems and construct flexible simulation architecture. We also evaluate the architecture model by implementing an example scenario that estimates the necessary network capacity for the experimental control system