Abstract: A communication device includes a packet-length table, a transmitter, a receiver, and a table update unit. The packet-length table stores, in association with an identifier of a network, a length of a packet to be transmitted to a device belonging to the network. The transmitter obtains a length of a packet associated with a network to which a destination device belongs, and transmits a packet whose length is equal to or less than the obtained length of a packet. The receiver receives a message when a length of the packet transmitted to the destination device is greater than a length of a packet that is able to be transmitted to a network included in a route leading to the destination device. The message indicates a maximum packet length. The table update unit updates a packet length associated with a network including the destination device to the maximum packet length.

Abstract: The control device of a LAN multiplexing apparatus performs a process to encapsulate a MAC frame received from at least any one of the LAN and the wireless LAN with a packet header including a packet network address including at least a multiplexing identifier and a MAC address and to send the encapsulated packet to the packet network, and a process to send a MAC frame obtained by decapsulating a packet received from the packet network to at least any one of the LAN and the wireless LAN corresponding to a destination of the MAC frame.

Abstract: Fully meshed virtual paths obtained with smaller number of settings, thus facilitating expansion of VPN service. A communication device in a virtual private network (VPN) having a VPN accommodation function for connecting an intra-organization network or inter-organization network through the Internet includes; a first means for generating a VPN address, a format of which includes both a VPN number for uniquely identifying a VPN in a certain scope and a closed address used in an organization or among organizations, either converting a packet header into a header having the above-mentioned VPN address or adding the above-mentioned VPN address to a packet header for transmission; and a second means for on receiving the packet having a header of the VPN address format, either converting the received packet into a packet format equivalent to an original packet format or removing a header having VPN address format.

Abstract: An address generator includes a storage device in which one or more second-protocol-family address prefixes are stored, the one or more second-protocol-family address prefixes each corresponding to a corresponding combination of at least a multiplexing identifier and a first-protocol-family address, and a controller configured to read, from the storage device, the second-protocol-family address prefix corresponding to a combination of at least the multiplexing identifier and the first-protocol-family address that is contained in a data block to be transferred via a backbone network to a destination network which uses the first protocol family, the read second-protocol-family address prefix serving as an address prefix for a network that is overlaid with the destination network, and configured to generate a second-protocol-family address containing the first-protocol-family address, the multiplexing identifier, and the read second-protocol-family address prefix, the generated second-protocol-family address ser

Abstract: The control device of a LAN multiplexing apparatus performs a process to encapsulate a MAC frame received from at least any one of the LAN and the wireless LAN with a packet header including a packet network address including at least a multiplexing identifier and a MAC address and to send the encapsulated packet to the packet network, and a process to send a MAC frame obtained by decapsulating a packet received from the packet network to at least any one of the LAN and the wireless LAN corresponding to a destination of the MAC frame.

Abstract: An address generator includes a storage device in which one or more second-protocol-family address prefixes are stored, the one or more second-protocol-family address prefixes each corresponding to a corresponding combination of at least a multiplexing identifier and a first-protocol-family address, and a controller configured to read, from the storage device, the second-protocol-family address prefix corresponding to a combination of at least the multiplexing identifier and the first-protocol-family address that is contained in a data block to be transferred via a backbone network to a destination network which uses the first protocol family, the read second-protocol-family address prefix serving as an address prefix for a network that is overlaid with the destination network, and configured to generate a second-protocol-family address containing the first-protocol-family address, the multiplexing identifier, and the read second-protocol-family address prefix, the generated second-protocol-family address ser

Abstract: A communication device includes a packet-length table, a transmitter, a receiver, and a table update unit. The packet-length table stores, in association with an identifier of a network, a length of a packet to be transmitted to a device belonging to the network. The transmitter obtains a length of a packet associated with a network to which a destination device belongs, and transmits a packet whose length is equal to or less than the obtained length of a packet. The receiver receives a message when a length of the packet transmitted to the destination device is greater than a length of a packet that is able to be transmitted to a network included in a route leading to the destination device. The message indicates a maximum packet length. The table update unit updates a packet length associated with a network including the destination device to the maximum packet length.

Abstract: Fully meshed virtual paths obtained with smaller number of settings, thus facilitating expansion of VPN service. A communication device in a virtual private network (VPN) having a VPN accommodation function for connecting an intra-organization network or inter-organization network through the Internet includes; a first means for generating a VPN address, a format of which includes both a VPN number for uniquely identifying a VPN in a certain scope and a closed address used in an organization or among organizations, either converting a packet header into a header having the above-mentioned VPN address or adding the above-mentioned VPN address to a packet header for transmission; and a second means for on receiving the packet having a header of the VPN address format, either converting the received packet into a packet format equivalent to an original packet format or removing a header having VPN address format.

Abstract: A packet filtering system able to streamline the filter conditions for filtering and to handle even IPsec, comprised of (i) a step of storing in a packet to be sent to a receiving side filtering information for use in filtering at the receiving side and sending this from the sending side and (ii) a step of receiving the packet from the sending side, detecting the filtering information stored in the packet, and use this for filtering at the receiving side. Further, this filtering information is comprised of a simple filter key.

Abstract: Disclosed herein is a VPN service with fully meshed virtual paths obtained with a smaller number of settings, thus facilitating expansion of the VPN service. This is attained by providing a communication device in a virtual private network (VPN) having a VPN accommodation function for connecting an intra-organization network or inter-organization network through the Internet.

Abstract: Disclosed herein is a VPN service with fully meshed virtual paths obtained with a smaller number of settings, thus facilitating expansion of the VPN service. This is attained by providing a communication device in a virtual private network (VPN) having a VPN accommodation function for connecting an intra-organization network or inter-organization network through the Internet.

Abstract: A load balancing system includes a pre-stage device and a plurality of post-stage devices. The pre-stage device receives original data that has been transmitted from the client device and for which a predetermined server address has been set as the destination address thereof, acquires transfer data having as the destination address thereof an address of any one corresponding post-stage device from among the post-stage devices on the basis of the original data, and transmits the transfer data. The corresponding post-stage device receives the transfer data that has been transmitted from the pre-stage device and which has the address of the corresponding post-stage device as the destination address, restores the transfer data to the original data for which the predetermined server address has been set as the destination address thereof, and transmits the original data to a server device connected to the corresponding post-stage device.

Abstract: A router for automatically generating an IP address including a position identifier portion and an interface identifier portion includes a routing table for storing each position identifier portion and information on an output route for the position identifier portion, a determining unit for determining for each of a plurality of ports whether a position identifier portion is assigned to a network to which the port is connected, a position identifier portion generating unit for referring to the routing table and generating a position identifier portion different from the position identifier portion registered in the routing table for a port not assigned a position identifier portion, and a routing unit for receiving routing information including a position identifier portion according to a dynamic routing protocol and registering the routing information in the routing table.

Abstract: Fully meshed virtual paths obtained with smaller number of settings, thus facilitating expansion of VPN service. A communication device in a virtual private network (VPN) having a VPN accommodation function for connecting an intra-organization network or inter-organization network through the Internet includes; a first means for generating a VPN address, a format of which includes both a VPN number for uniquely identifying a VPN in a certain scope and a closed address used in an organization or among organizations, either converting a packet header into a header having the above-mentioned VPN address or adding the above-mentioned VPN address to a packet header for transmission; and a second means for on receiving the packet having a header of the VPN address format, either converting the received packet into a packet format equivalent to an original packet format or removing a header having VPN address format.

Abstract: A communication device includes a static routing table, a dynamic routing table and a judging unit. The judging unit, if no failure occur in a static route, selects the static route based on routing information given from the static routing table as a route to which a packet should be forwarded. The judging unit, if the failure occurs in the static route, selects a dynamic route based on routing information given from the dynamic routing table as a route to which the packet should be forwarded.

Abstract: A router for automatically generating an IP address including a position identifier portion and an interface identifier portion includes a routing table for storing each position identifier portion and information on an output route for the position identifier portion, a determining unit for determining for each of a plurality of ports whether a position identifier portion is assigned to a network to which the port is connected, a position identifier portion generating unit for referring to the routing table and generating a position identifier portion different from the position identifier portion registered in the routing table for a port not assigned a position identifier portion, and a routing unit for receiving routing information including a position identifier portion according to a dynamic routing protocol and registering the routing information in the routing table.

Abstract: A prefix generator that is possessed by an ISP, sets in advance a prefix that includes an SLAID which is a user setting bit string that is to be set by a user actually and stores the prefix in a card. When the user inserts the card in a router, a prefix assigning processor assigns the prefix in the card to interfaces.

Abstract: A packet filtering system able to streamline the filter conditions for filtering and to handle even IPsec, comprised of (i) a step of storing in a packet to be sent to a receiving side filtering information for use in filtering at the receiving side and sending this from the sending side and (ii) a step of receiving the packet from the sending side, detecting the filtering information stored in the packet, and use this for filtering at the receiving side. Further, this filtering information is comprised of a simple filter key.

Abstract: Fully meshed virtual paths obtained with smaller number of settings, thus facilitating expansion of VPN service.

Abstract: A communication device includes a static routing table, a dynamic routing table and a judging unit. The judging unit, if no failure occur in a static route, selects the static based on routing information given from the static routing table as a route to which a packet should be forwarded. The judging unit, whereas if the failure occur in the static route, selects a dynamic route base on routing information given from the dynamic routing table as a route to which the packet should be forwarded.