| US 7,499,396 B2 | ||
| Router selecting method and router apparatus | ||
| Masayuki Kumazawa, Yokohama (Japan); Taisuke Matsumoto, Yokohama (Japan); Shinkichi Ikeda, Yokohama (Japan); Hirokazu Kobayashi, Inagi (Japan); Makoto Funabiki, Yokohama (Japan); and Toyoki Kawahara, Chofu (Japan) | ||
| Assigned to Panasonic Corporation, Osaka (Japan) | ||
| Appl. No. 10/554,717 PCT Filed Oct. 01, 2004, PCT No. PCT/JP2004/014891 § 371(c)(1), (2), (4) Date Oct. 28, 2005, PCT Pub. No. WO2005/034440, PCT Pub. Date Apr. 14, 2005. |
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| Claims priority of application No. 2003-344151 (JP), filed on Oct. 02, 2003; and application No. 2004-279083 (JP), filed on Sep. 27, 2004. | ||
| Prior Publication US 2006/0203828 A1, Sep. 14, 2006 | ||
| Int. Cl. H04L 12/26 (2006.01) | ||
| U.S. Cl. 370—230 [370/390; 370/401; 709/242; 709/243] | 22 Claims |
| 2. A router selecting method in a local area network (LAN) including plural routers, at least one of the plural routers performs
relaying with an external network, the router selecting method comprising:
a step of periodically multicasting, by each of the routers in a common segment, a multicast packet including an identifier
of the respective router;
a step of selecting, by a respective router, a destination to forward a data packet among other routers in the common segment,
based on information included in the multicast packets received from the other routers in the common segment;
a step of determining, by each of the routers, in accordance with conditions determined in advance whether to relay the data
packet, received from a node or a router in the common segment, to another segment;
a step of transferring by the router, when the router determines not to relay the received data packet to another segment,
the data packet to the selected router;
a step of transmitting by the router, when the router relays the received data packet to another segment, if the data packet
is not directly received from a source node which is the source of the received data packet but is a forwarded packet which
is forwarded from another router, information of a reporting relay indicating that the router is capable of relaying the forwarded
packet, to a forwarding router which forwarded the packet; and
a step of judging by the forwarding router, when the forwarding router receives the information of the reporting relay, whether
the forwarding router is the original router that has forwarded the data packet specified in the information of the reporting
relay, and, if the forwarding router is the original router that has forwarded the data packet, transmitting by the router,
a redirection message which specifies that the router is capable of relaying a data packet to the source node which sent the
data packet and, if the forwarding router is not the original router that has forwarded the data packet specified in the information
of the reporting relay, transferring the information of the reporting relay to a previous router that forwarded the data packet.
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