Alaxala Networks Corporation

Hitachi, Ltd.

Makoto Kitani

Takahisa Miyamoto

Keiichiro Yamate

Takeshi Shibata

Hidemitsu Higuchi

Shinichi Akahane

Toshiaki Suzuki

Masahiko Mizutani

Kazuyoshi Hoshino

Tatsuya Watanuki

Morihito Miyagi

Atsushi Kimoto

Tomoyuki Iijima

A transfer apparatus is configured to: calculate a total cost of a first route in a first network that starts from a source transfer apparatus and ends at a destination transfer apparatus; obtain a particular cost being a cost between the source transfer apparatus and a first line, which couples the source transfer apparatus and its own transfer apparatus, in a second route, which starts from the source transfer apparatus and reaches the destination transfer apparatus via its own transfer apparatus; calculate a differential between the total cost and the particular cost; set, based on the differential, a cost between its own transfer apparatus and a second line, which couples its own transfer apparatus and the destination transfer apparatus, to a value that causes the source transfer apparatus to select the second route rather than the first route; and notify the cost value to the source transfer apparatus.

Transfer apparatus, server, and route changing method

Trees employing the following two elements are used to determine communicable ranges: paths within a transmission network that are set for data transfer between adjacent communicating devices; and the adjacent communicating devices located at both ends of the paths. The adjacent communicating devices corresponding to the roots of the trees are called adjacent communicating devices located at both ends of a path that has become incommunicable due to a fault within the transmission network.

Fault tolerant communication system, method, and device that uses tree searching

Provided is a network management system for managing a plurality of packet relay devices, the network management system comprising: the plurality of packet relay devices constituting networks; and a display device for displaying configurations of the networks, in a case where it is determined that a virtual packet relay device identifier of the virtual packet relay device that is assigned a second-network identifier associated with the extracted second-network identifier is registered in a first-network configuration table, a first-work identifying module is configured to associate a first-network identifier that is associated with the virtual packet relay device identifier with the obtained configuration information, and register the association between the first-network identifier and the obtained configuration information in the first-network configuration table.

Network management system and management computer

A network management apparatus is previously registered with a physical connection relationship and positional information of a plurality of network relay apparatuses which form part of a network, as well as a configuration definition corresponding to the positional information, such that the network management apparatus can initially detect network relay apparatuses connected to the network management apparatus, and distribute a configuration definition, which takes into account a connection relationship, to the network relay apparatuses connected thereto to set the configuration definition in the network relay apparatuses in order. In this way, even if wiring is freely made, the configuration definition which should be set in each network relay apparatus can be appropriately distributed to and set in one adjacent network relay apparatus to another. Upon occurrence of a fault, the network can be appropriately recovered by a previously set recovering scheme.

Network operation management system

The network relay device of the invention makes a pair with at least a specific network device to relay data in a network. The network relay device includes: a control module that sends and receives a control frame signal to and from the specific network device, selects either of a master mode and a backup mode based on at least the control frame signal sent from the specific network device, and changes a working state according to a result of the selection; and a communication module that is under control of the control module to open a port and enable data transmission via a line linked to the port in the case of setting a master state to the working state, and to block off the port and disconnect the line linked to the port in the case of setting a backup state or another non-master state to the working state. The control module changes the working state from the backup state to a first intermediate state in response to selection of the master mode, determines whether the specific network device is in the backup state, based on the control frame signal sent from the specific network device, and changes the working state from the first intermediate state to the master state after confirmation that the specific network is in the backup state.

Network relay system and control method thereof

Enables control of data transmission within a network. For this, for example, a network relay apparatus makes a determination as to permission to transmit data, based on a condition relating to at least one of the transmission origin of the data and transmission destination of the data. An administration unit contains administration information indicating permission to use shared devices by users of clients. The connection relay apparatus for a target client acquires user identifying information from the target client. The administration unit acquires the user identifying information from the connection relay apparatus for a target client, and referring to the administration information, detects a target shared device that is one of the shared device permission to use of which has been granted to a user of the target client. The administration unit notifies the connection relay apparatus for the target shared device of permission for transfer of data between the target client and the target shared device, together with information identifying the target client. Upon receiving the notification, the connection relay apparatus for the target shared device sets the condition so as to change the data transmission permission between the target client and the target shared device from not authorized to authorized.

Data transmission control on network

A network management apparatus is for managing a plurality of switching devices that relay data through a data communication network. The network management apparatus includes a configuration information storage, a connectivity relationship detector and a configuration information modifier. The configuration information storage stores first configuration information. The first configuration information is configured in the switching devices and includes information to be determined in accordance with connectivity relationships among the switching devices. The connectivity relationship detector detects changes of connectivity relationships among the switching devices. The configuration information modifier dynamically modifies the first configuration information in accordance with detected changes of connectivity relationships.

Network management apparatus and switching apparatus

A handling address range is pre-assigned to each of switching devices consisting a network switching system. The switching device has a data receiving unit, an assigned data transport unit, an unassigned data transport unit, and a lower transport layer transport unit. The data receiving unit receives data including a destination address in a network layer and a destination identifier in a lower transport layer. If the destination identifier specifies the device itself, the assigned data transport unit and the unassigned data transport unit perform data transfer, whereas if the destination identifier specifies a device other than itself, the lower transport layer transport unit performs data transport. When the destination address is assigned address, the assigned data transport unit generates data including an identifier of a device corresponding to the destination address, and transports the generated data. When the destination address is not assigned address, the unassigned data transport unit transport the data to a switching device among the plurality of switching devices consisting the switching system to which the destination address is assigned.

Network switching system

A secure storage system for securely accessing a storage device on a network and improving volume management scalability, consisting of a client having a VPN capability; a storage device in an SAN; a management apparatus having a means for managing a storage capacity and a logical volume allocated to the storage device; a converter for converting a protocol used in the SAN to a protocol used in a LAN/MAN/WAN and vice versa; and a conversion apparatus having the VPN capability. A VPN is provided between the client and the conversion apparatus. The conversion apparatus is provided with a mapping between the VPN and an access range of the storage device. A VPN-ID is used for identifying the VPN. An address in the logical volume is used for the access range of the storage device.

Growing community of inventors

Yokohama, Japan

Makoto Kitani