Patent ID: 8514741

Claim:
A packet forwarding device which comprises a plurality of input lines and a plurality of output lines, and transfers a packet inputted from the input line to one or more of the output lines, the packet forwarding device comprises: a packet transfer processing section which includes a header processing section, a receiving circuit to receive the packet via one of the input lines, and a packet transmission circuit to send the packet via one of the output lines; an importance degree determination section to determine an importance degree of the packet from header information of the packet; a measuring section to measure an amount of packets reaching the packet transfer processing section for each packet importance degree; and a performance determination section to determine packet processing performance of at least one of the header processing section, the receiving circuit, and the packet transmission circuit based on the measured amount of packets for each importance degree, the packet processing performance being a capacity of processing for entire packets to be processed having different importance degrees, and packets being discarded or delayed when the amount of packets exceeds the packet processing performance, and to change processing performance of at least one of the header processing section, the receiving circuit, and the packet transmission circuit according to the determined packet processing performance; wherein the performance determination section obtains a first estimated bandwidth based on the amount of packets of a first importance degree, and a second estimated bandwidth based on the amount of packets of a second importance degree lower than the first importance degree, and wherein the packet processing performance is a result obtained by multiplying the first estimated bandwidth by a first magnification to prevent the packet of the first importance degree from being discarded and by adding the multiplying result to the second estimated bandwidth, or a result obtained by adding a value obtained by multiplying the first estimated bandwidth by the first magnification and a value obtained by multiplying the second estimated bandwidth by a second magnification smaller than the first magnification.