Patent ID: 7719986

Claim:
A bandwidth control device for limiting and guaranteeing a bandwidth for each of classes when transmitting a packet belonging to any of the classes to a communication network, comprising: a first register for storing an interface limiting time to be the earliest time at which a packet can be subsequently transmitted from a transmitting device for transmitting a packet to the communication network in order to control a communication bandwidth of the transmitting device to be equal to or smaller than an allowable bandwidth permitted for the transmitting device; a second register provided for each of the classes and serving to store a class limiting time to be the earliest time at which a packet of a corresponding class can be subsequently transmitted in order to control a communication bandwidth of the class to be equal to or smaller than an allowable bandwidth of the class; a third register provided for each of the classes and serving to store a class guarantee time to be a final time at which a packet of a corresponding class is to be subsequently transmitted in order to give the class a communication bandwidth which is equal to or greater than a guarantee bandwidth of the class; a class determining unit for determining, as a transmitting object class, a class from which a packet is to be transmitted based on the class limiting time and the class guarantee time in each of the classes; a transmitter for transmitting a packet belonging to the transmitting object class; and a calculator for recalculating the interface limiting time, the class limiting time of the transmitting object class, and the class guarantee time of the transmitting object class based on a data volume of the packet belonging to the transmitting object class and storing results of the recalculation in the first to third registers.