Presents an online delay-evaluation approach - delay window (DW), for networked control systems, which characterizes the time delays online without a synchronized clock in the network and any prior assumptions of time delays. Based on this approach, an optimal control scheme is designed to achieve desired performance despite the uncertain delays in the system. The experimental results based on a CANbus experimental setup illustrate the effectiveness of the proposed control design and present a satisfactory performance of the closed-loop system.