US006038233A [ii] Patent Number: 6,038,233 [45] Date of Patent: Mar. 14,2000
[54] TRANSLATOR FOR IP NETWORKS,
NETWORK SYSTEM USING THE
TRANSLATOR, AND IP NETWORK
COUPLING METHOD THEREFOR
[75] Inventors: Shinichi Hamamoto, Yamato-chi; Ken Watanabe, Kawasaki; Kazuaki Tsuchiya, Yokohama; Naoya Ikeda,
Ebina, all ol Japan
[73] Assignee: Hitachi, Ltd., Tokyo, Japan
[21] Appl. No.: 08/887,123
[22] Filed: Jul. 2, 1997
[30] Foreign Application Priority Data
Jul. 4, 1996 [JP] Japan 8-174768
[51] Int. CI.7 H04L 12/66; H04L 29/06
[52] U.S. CI 370/401; 370/466
[58] Field of Search 370/401, 402,
370/392, 465, 466, 467; 709/249
[56] References Cited
U.S. PATENT DOCUMENTS
5,793,763 8/1998 Mayes et al 370/466
A translator for coupling a first network such as an internet protocol version 4 (IPv4) and a second network such as an internet protocol version 6 (IPv6) having different addressing architectures for IP addresses due to a difference in version or the like so as not to exhaust the IP addresses ol one ol the two networks, a network system using the translator, and a network coupling method therefor are provided. When a packet is translerred from the IPv6 network to the IPv4 network, the translator assigns any ol a plurality ol previously prepared IPv4 addresses to an IPv6 address stored in a source storing field ol the IPv6 packet. The assigned address is stored in a source storing field ol an IPv4 packet. A packet translation unit is provided for assigning the foregoing IPv6 address to an IPv4 address stored in a destination storing field ol the IPv4 packet, when a packet is translerred from the IPv4 network to the IPv6 network, and for storing this address in a destination storing field ol the IPv6 packet.
8 Claims, 11 Drawing Sheets
