Abstract: A traffic control method for providing a guaranteed/predictive service which can guarantee a quality of service QOS by controlling transmission routes of various traffic data with a policing function using a moving ceiling MC function and a packet scheduling function using a first in first out FIFO or weighted fair queueing WFQ method, includes the steps of: observing an average transmission rate of packet data inputted through each route by using the MC method; determining whether the packet data satisfies passing conditions of the MC method by a result of the observation; storing the packet data in an output buffer when the packet data satisfies the passing conditions thereof; storing the packet data in an empty space of a certain storing unit, and abandoning the packet data when there is no empty space, in the case that the packet data does not satisfy the passing conditions of the MC method; and transmitting the packet data to a receiving side through a single transmission route after detecting the output