Hitachi, Ltd.

Hitachi Process Computer Engineering, Inc.

Shuji Ohno

Norihiro Goto

Tatsuya Watanuki

Takashi Kitayama

Naoto Matsunami

Takashi Oeda

Minoru Yoshida

Takeshi Ishizaki

Kiyoshi Honda

Naoya Ikeda

Toshikazu Yasue

Keiichi Nakane

Takahisa Miyamoto

Shoichi Miyazawa

Masakazu Okada

Masatoshi Takihiro

Masataka Ohta

Syoji Yamaguchi

Tetsuya Kawahara

Yoshimi Fujimata

An automatic address distributing method, computer program and system for automatically examining addresses already assigned to terminals connected to a network without regard to the status of the existing terminals and removed terminals. An address may be assigned to a terminal by apparatus other than a DHCP server. After a Dynamic Host Configuration Protocol (DHCP) server has been started, addresses currently used in a network are examined by a duplicate-address examining unit and the status of the address are stored in an in-use-address database (DB). When a terminal makes a request for distribution of an address, the DHCP server distributes an address that is currently not used in the network. In the examination carried out by the duplicate-address examining unit, an inquiry about the entire name information controlled by a Domain Name Service (DNS) server is made to the DNS server. Results of the inquiry are also stored in the in-use-address DB. Then, a mobile-agent DB is examined for a mobile agent. An inquiry about information on movement status of mobile terminals is made to the mobile agent cataloged in the mobile-agent DB. Results of this inquiry are also stored in the in-use-address DB.

Automatic address distributing system

A user terminal sends a resource reservation request message in which time information indicative of time to perform a communication is designated to a switching node to which the self user terminal is linked. The switching node manages a reservation state of each of resources which can be used by the self switching node among resources of a network together with time information indicative of time when a communication using the resource is performed. When the resource reservation request message is received, an unreserved resource is obtained at a time indicated by the time information designated in the resource reservation request message, the obtained resource is reserved, and a resource reservation result notice message indicative of the reservation result is returned to the user terminal. A resource management server is also provided so as to reserve a network resource with a simple operation. The reservation can be performed in consideration of priority and cost of a communication. Reservation information can be always recognized by a client. When resource reservation is failed, an alternative plan is automatically calculated and presented.

Network and switching node in which resource can be reserved

A label switching router which includes a data relay controller for transferring IP datagrams and controlling the transfer, detecting any transfer IP datagram satisfying a particular condition, and controlling an ATM switch based on a detection result and an ATM switch for switching between adjacent nodes for transferring ATM cells. An operation state of the data relay controller is monitored and a user-specified VP route is set to the ATM switch according to a fault circumventing route table, thereby continuing communication between the adjacent nodes on both side of this ATM switch if a fault occurs on the data relay controller.

Switching router and a datagram transfer system

A client server system has clients, a server of execution system, and a server of fault auxiliary system are connected. A process administrator is provided in each one of the server of execution system and the server of fault auxiliary system. When a fault has occurred in a disk processor in the server of execution system, the process administrator in the server of execution system transmits only 'requests' relating to the disk processor among 'requests' received from clients to the server of fault auxiliary system. A process administrator in the server of fault auxiliary system conducts corresponding server processing on the 'requests' transmitted from the server of execution system.

Redundant client server system

A plurality of commands which may be sent sequentially from a host computer are interpreted by a host command interpreter to generate a disk command for each disk unit. When these commands make up an access demand for a single continuous area, they are grouped into a single command, which is executed substantially at the same time at each disk unit. Also, a plurality of RMW processing systems having different command issued to disk units are available. A selection condition is detected from the I/O demand information supplied by a host computer, and an optimum one of a plurality of RMW processing systems is selected and executed on the basis of the selection condition.

Array disk controller for grouping host commands into a single virtual

In an information communication system for performing both point-to-point communication and point-to-multipoint communication between a host computer and terminals by using same lines while distributing loads of data communication, data communication report tables are provided on a main storage unit of the host computer for each type of communication. The data communication process is executed distributively at each CPU unit and communication interface unit of the host computer and at each control module of a communication control unit. A plurality of destination pattern tables indicating data destinations are provided for point-to-multipoint communication. For the point-to-multipoint communication, CPU unit designates a particular destination pattern table for each interface unit, and data transmission is requested to each control module in accordance with the destination pattern table.

Information communication system for point-to-point communication and

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Yokohama, Japan

Shuji Ohno