| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a packet relay device that is provided only to one side of a node conducting packet communication so as to attain path control by which both a forward path and a return path depend on application. SOLUTION: A packet relay device 12 relays a packet between an inside node 10-2 and an outside IP network 18. A class processing section 40 classifies transmission packets in the IP network by each application type, a different virtual IP address is assigned to the classified packets, a transmission packet relay section 42 converts a sender address of a transmission packet to be relayed to the IP network into a class dependent virtual IP address to set up a class dependent IP communication path 20-1 or 20-2. A return packet relay section 44 inversely converts a destination virtual IP address of a return packet from the IP network passing through the class dependent IP communication path 20-1 or 20-2 into an original address referring to the address conversion result of a transmission packet relay section 42.</p> |
