Patent ID: 7225269
Filing Date: 2007-05-29
Classification: H04L

Abstract:
1. A network gateway system having a network gateway device that interconnects networks, said network gateway system comprising: an administration center that holds and creates a gateway rule for controlling a packet, wherein said network gateway device holds the gateway rule; wherein when receiving a packet, if a gateway rule corresponding to the received packet exists, said network gateway device handles the received packet according to the gateway rule; wherein if there is no gateway rule corresponding to the received packet, said network gateway device transfers the received packet to the administration center, and then receives a gateway rule corresponding to the packet from the administration center to perform update; wherein in the network gateway device, an effective time during which the gateway rule is held is determined, and thereby a gateway rule whose effective time has expired is deleted, and wherein said network gateway device comprises a gateway-rule storing table for holding the gateway rules; and wherein when receiving the gateway rule from the administration center, if no space area in the gateway-rule storing table exists, a gateway-rule entry with the shortest remaining effective time is first deleted from among the gateway rules stored in the gateway-rule storing table.