Along with being more popular of the mobile device, there are more and more mobile applications have been developed nowadays. However among these applications are 'Over-The-Top (OTT)' applications which have been provided by the vendor of applications holds the biggest amount of them. And OTT merely use bandwidth which is offered by operators and this has caused operator have to afford a big amount of money for bandwidth but with very less income in return. Hence, here are many operators trying their best to join the mechanism of Deep Packet Inspection (DPI), and then assign the packets with different Quality of Service (QoS) rules according to their different kinds of signature. However to the router and backbones this will be a heavy burden. Consequently, this research mainly analyze how the mechanism of the DPI affects the Policy Control and Charging (PCC) System, and moves forward a step to investigate the rate of identification of DPI at different detecting rate in order to get the high successful detection rate but with the lower cost. In conclusion, this research's main purpose is to build reference of DPI mechanism.