Patent ID: 8291106

Claim:
A network system comprising: a first router; a second router coupled to the first router via a network; and, a third router coupled to the second router via a network, wherein the first router transmits at least one of a first packet which indicates a first degree of priority lower than a second degree of priority or a second packet which indicates the second degree of priority, wherein the second router receives the first packet, monitors a first bandwidth to be used for a packet indicating the second degree of priority, and determines whether or not the first degree of priority of the first packet can be changed on the basis of results of monitoring the first bandwidth, and rewrites a degree of the priority of the first packet to the second degree of priority if it is determined that the first degree of priority of the first packet can be changed to the second degree of priority, and wherein, if it is determined that the first degree of priority of the first packet can be changed to the second degree of priority, the second router transmits, to the third router, the first packet having the second degree of priority after being changed from the first degree of priority, and the third router receives the transmitted first packet from the second router.