A traffic control application programming interface for abstracting the use of traffic control components to client applications to provide quality of service. The traffic control interface accepts input from a client application and based on that input, communicates with the operating system to control kernel level traffic control components. The client can register with the traffic control interface, and it can open and close interfaces, add, modify, and delete flows on those interfaces, and attach or delete filters on the flows. The client can also obtain data on any currently active interface, flow, or filter. The traffic control interface will send the appropriate message to the operating system, directing that the necessary tasks be performed by either a packet scheduler or a packet classifier. Those kernel level components then return through the operating system the results of the operations requested, and that return data will be passed back to the client application.