A method for managing data throughput of a network device is provided. The method includes: determining a network communication as belonging to a first class or a second class; enqueuing each packet received through the network communication determined as belonging to the first class to a first queue, and enqueuing each packet received through the networking communication determined as belonging to the second class to a second queue; dequeuing the first and second queues at a dequeuing ratio; determining a data rate of dequeuing the second queue; and adjusting the dequeuing ratio based on the data rate of dequeuing the second queue thus determined, a total bandwidth, and a guaranteed minimum bandwidth for the network communication determined as belonging to the first class.