Abstract: The traffic modeling of multimedia stream provided by Oechslin is theoretically analyzed. The PLP (packet loss probability) variation with network utility and the transition rate of middle state has been studied. It shows that the new symmetric three states ON/OFF model can give a higher loss rate than the standard ON/OFF model. As the symmetric three states ON/OFF is relatively simple in computation, in some special case, it can provide better estimation than the traditional ON/OFF model.