Under the IEEE standard 802.4, the SIMAN simulation language is used to simulate the effect of the Token Holding Time. Simulation results are shown in terms of response time, transmission time, and queue delay time for different message size and different traffic road. Analytical model is derived, which is helpful information to understand the characteristic of communication systems. The maximum and recommended buffer storage size characteristics are investigated. By utilizing the information of the number of messages in the queue, communication network can be designed more effectively by reducing the unnecessary buffer memory size.