Abstract: A relay device comprises: a routing controller configured to perform learning of routing information, which includes area information used to identify a relay area of communication packets and a network address of one or more other relay devices, and to determine a relay route of the communication packets, based on the learnt routing information; and a relay module configured to send the communication packets received by the relay device to a destination address of the received communication packets, based on the determined relay route. When the relay device receives a disaster notification packet notifying of a disaster area and when the determined relay route includes the disaster area, the routing controller changes the relay route to an alternative relay route that does not include the disaster area.

Abstract: In a network relay router 10, a multicast routing protocol processing module 11A sequentially sends a join request message (CP1) to a router 30a functioning as a rendezvous point via an interface 101, based on the settings of a multicast group address or destination address and a sender VRF name. The network relay router 10 receives a multicast packet (DP1) from the router 30a via the interface 101 and acquires a sender address or source address of a transmission device SE from the received multicast packet. The network relay router 10 sends a join request message (CP2) via an interface 102 on the side of the transmission device SE and receives a multicast packet via the interface 102. This establishes an optimum multicast route (MR) between the transmission device SE and the network relay router 10.

Abstract: A relay device comprises: a routing controller configured to perform learning of routing information, which includes area information used to identify a relay area of communication packets and a network address of one or more other relay devices, and to determine a relay route of the communication packets, based on the learnt routing information; and a relay module configured to send the communication packets received by the relay device to a destination address of the received communication packets, based on the determined relay route. When the relay device receives a disaster notification packet notifying of a disaster area and when the determined relay route includes the disaster area, the routing controller changes the relay route to an alternative relay route that does not include the disaster area.

Abstract: For continuing multicast data transfer according to path control information after being switched from an active status to a standby status, it is necessary that the standby status hold the same path control information as the active status. However, a synchronization of the path control information thereof is not guaranteed. To solve the above-mentioned problem, this invention provides a data transfer apparatus coupled to a network, including a plurality of interfaces for transmitting and receiving data, in which the data transfer apparatus is configured to: create transfer destination information for correlating a destination of the data with the interfaces for transmitting the data to be transmitted to the destination; and transmit, upon reception of multicast data via one of the interfaces before being judged that the transfer destination information has been created, the multicast data from at least one of the interfaces irrespective of the transfer destination information.

Abstract: In a network relay router 10, a multicast routing protocol processing module 11A sequentially sends a join request message (CP1) to a router 30a functioning as a rendezvous point via an interface 101, based on the settings of a multicast group address or destination address and a sender VRF name. The network relay router 10 receives a multicast packet (DP1) from the router 30a via the interface 101 and acquires a sender address or source address of a transmission device SE from the received multicast packet. The network relay router 10 sends a join request message (CP2) via an interface 102 on the side of the transmission device SE and receives a multicast packet via the interface 102. This establishes an optimum multicast route (MR) between the transmission device SE and the network relay router 10.

Abstract: Packets of mobile communication protocol which a mobile terminal sends and receives are monitored and when it is detected that a mobile terminal to which a multicast data packet is transferred moved to another network, a multicast gateway apparatus connected to the moving destination network makes a group attend request and transfers the multicast data packet to the moved mobile terminal.

Abstract: A multicast communication device receives data packets multicast for receiving terminals which terminals do not support multicast communication and that are requesting multicast data packets. The multicast communication device then forwards the data packets to the receiving terminals. Communication from the receiving terminal accessing the sending terminal sending data packets to obtain information is monitored. Based on the access contents, a join group request is issued for the group address used by the multicast delivery. The multicast communication device stores service information such as the address of the sending terminal and the destination address of data packets sent by the sending terminal. If the service to be accessed by the receiving terminal is present, multicast delivery of data packets is requested. The multicast communication device forwards received multicast data packets to the receiving terminal.

Abstract: For continuing multicast data transfer according to path control information after being switched from an active status to a standby status, it is necessary that the standby status hold the same path control information as the active status. However, a synchronization of the path control information thereof is not guaranteed. To solve the above-mentioned problem, this invention provides a data transfer apparatus coupled to a network, including a plurality of interfaces for transmitting and receiving data, in which the data transfer apparatus is configured to: create transfer destination information for correlating a destination of the data with the interfaces for transmitting the data to be transmitted to the destination; and transmit, upon reception of multicast data via one of the interfaces before being judged that the transfer destination information has been created, the multicast data from at least one of the interfaces irrespective of the transfer destination information.

Abstract: Packets of mobile communication protocol which a mobile terminal sends and receives are monitored and when it is detected that a mobile terminal to which a multicast data packet is transferred moved to another network, a multicast gateway apparatus connected to the moving destination network makes a group attend request and transfers the multicast data packet to the moved mobile terminal.

Abstract: Disclosed is system for multicast distribution of stream data containing audio and video to a multicast network by way of a unicast network. System is comprised of a distribution device to distribute data sent from a transmit terminal to multiple receive terminals. The distribution device is comprised of information from the transmit terminal, a storage means for storing information linked to address information for distributing data to multiple receive terminals, a data distribution request-receive means to receive a request for data distribution from a receive terminal, and a data transmit-request means to search the linked information based on the data request-receive means and receive a request for transmission of data to the transmit terminal.

Abstract: A multicast communication device receives data packets multicast for receiving terminals which terminals do not support multicast communication and that are requesting multicast data packets. The multicast communication device then forwards the data packets to the receiving terminals. Communication from the receiving terminal accessing the sending terminal sending data packets to obtain information is monitored. Based on the access contents, a join group request is issued for the group address used by the multicast delivery. The multicast communication device stores service information such as the address of the sending terminal and the destination address of data packets sent by the sending terminal. If the service to be accessed by the receiving terminal is present, multicast delivery of data packets is requested. The multicast communication device forwards received multicast data packets to the receiving terminal.

Abstract: A multiplex router device, having a multiplex configuration, is instrumental in reducing internal and external traffic flows for a routing protocol process that occurs at a time of system switchover. A data base integration module, in a route calculation unit in the active mode, stores network link-state information collected by a routing protocol packet transmission-reception module in a link-state data base, and at the same time sends the information to a route calculation unit, but does not send routing protocol information collected. In the route calculation unit in the standby mode, a data base integration module that received the network link-state information stores its contents into its own link-state data base. When a failure occurs in the route calculation unit in the active mode, the route calculation unit performs the routing protocol process by using the stored link-state data base.

Abstract: A multiplex router device, having a multiplex configuration, is instrumental in reducing internal and external traffic flows for a routing protocol process that occurs at a time of system switchover, wherein a data base integration module 17 in a route calculation unit 11a in the active mode stores network link-state information collected by a routing protocol packet transmission-reception module 14 in a link-state data base 22, and at the same time sends the information to a route calculation unit 11b, but does not send routing protocol information collected, while on the other hand, in the route calculation unit 11b in the standby mode, a data base integration module 17 that received the network link-state information stores its contents into its own link-state data base 22, and wherein when a failure occurs in the route calculation unit 11a in the active mode, the route calculation unit 11b performs the routing protocol process by using the stored link-state data base 22.

Abstract: This invention provides a router device facilitating a management of connection of a managing person and assuring a communication quality of each of the connections. The router device 1 determines a communication quality required by the communication of the packet in reference to a protocol information, an application acknowledging information and a priority information, transmits the control packet having the determined communication quality set therein to another router device contained in the same connection and further performs a traffic control (a preferential processing of a packet or the like) satisfying a communication quality indicated by the transmitted or received control packet in respect to the packet of the aforesaid connection.

Abstract: A router device facilitates management of connection of a manager and assures communication quality of each of the connections. The router device determines a communication quality required by the communication of the packet in reference to a protocol information, an application acknowledging information and a priority information, transmits the control packet having the determined communication quality set therein to another router device contained in the same connection and further performs a traffic control (a preferential processing of a packet or the like) satisfying a communication quality indicated by the transmitted or received control packet in respect to the packet of the aforesaid connection.

Abstract: A multiplex router device, having a multiplex configuration, is instrumental in reducing internal and external traffic flows for a routing protocol process that occurs at a time of system switchover. A data base integration module, in a route calculation unit in the active mode, stores network link-state information collected by a routing protocol packet transmission-reception module in a link-state data base, and at the same time sends the information to a route calculation unit, but does not send routing protocol information collected. In the route calculation unit in the standby mode, a data base integration module that received the network link-state information stores its contents into its own link-state data base. When a failure occurs in the route calculation unit in the active mode, the route calculation unit performs the routing protocol process by using the stored link-state data base.

Abstract: A router device facilitates management of connection of a manager and assures communication quality of each of the connections. The router device determines a communication quality required by the communication of the packet in reference to a protocol information, an application acknowledging information and a priority information, transmits the control packet having the determined communication quality set therein to another router device contained in the same connection and further performs a traffic control (a preferential processing of a packet or the like) satisfying a communication quality indicated by the transmitted or received control packet in respect to the packet of the aforesaid connection.

Abstract: An ATM switch for providing an electrical interconnection between a connection-oriented ATM LAN of an ATM system and a connectionless legacy LAN is provided.