The invention is directed to a traffic control system. The traffic control system comprises a communication device. The communication device includes a traffic type differentiation unit for differentiating a traffic type of an application that generates traffic to be processed on a communication network, a traffic control execution unit for controlling the traffic according to a traffic control condition corresponding to the traffic type, and a setting change reception unit for receiving setting change information on the traffic type or setting change information on the traffic control condition from the communication network. The traffic control system also comprises a setting change information transmission device provided on the communication network for transmitting setting change information.