GATEWAY SYSTEM AND A CONTROLLING METHOD THEREOF, ESPECIALLY CONCERNED WITH ACQUIRING AND PROCESSING THE DATA STREAMS BETWEEN A NETWORK AND A TARGET NODE AND RETRANSMITTING THE PROCESSED DATA STREAMS TO THE DESTINATION

摘要

PURPOSE: A gateway system and a controlling method thereof are provided to acquire and process the data streams between a network and a target node connected to the network while operating in a state of being synchronized with the IP address of the target node connected with a network and to retransmit the processed data stream to the destination. CONSTITUTION: A gateway system(3) comprises a storage part(33), a control part(31), a MAC address conversion part(37), a router part(41), a filter(43), a filter information table(45), a data processing part(47), the first port(35), and the second port(39). The storage part(33) stores the IP address of a target node(5). The control part(31), when the gateway system(3) is initialized, reads the IP address of the target node(5) stored in the storage part(33), and sets up the IP address of the second port(39) on the basis of the IP address of the target node(5). Then the control part(31) obtains the MAC address of the target node(5) through the second port(39) using an ARP(Address Resolution Protocol). The MAC address conversion part(37) sets up the MAC address of the target node(5) as the MAC address of the first port(35). The router part(41) establishes a data transfer path. In case that the IP address of the target node(5), to which data are transferred, is identical to the IP address of the first port(35), the router part(41) transfers the data to the IP address of the target node(5) without executing local loopback processing. The data processing part(47) intercepts and processes the data streams between a network(1) and the applications of the target node(5) or makes out a new data stream and transmits it.