Hitachi, Ltd.

Tetsuo Oura

Sunao Sawada

Tatsuya Watanuki

Toshikazu Yasue

Seiji Kageyama

Katsumi Tadamura

Kazuaki Tsuchiya

Ken Watanabe

Naoya Ikeda

Yoshihito Sako

Yoshinori Watanabe

Yuuji Saeki

Shiro Oishi

A mobile node moves from a first IP (Internet Protocol) network to a second IP network in a network system in which the first IP network capable of executing communication in accordance with both first and second kinds of IPs and the second IP network capable of executing communication in accordance with only the first kind of IP are connected with each other. When the mobile node communicates a message with other nodes on the first network after its movement accordance with the second kind of IP, a header for the movement containing both home and foreign addresses of the first kind in IP is added to a header containing home and foreign addresses in the second kind of IP, and put to the message, is added. The message to which the movement header is thus added is used for the communication between a first mobile agent on the first network and a second mobile agent on the second network, or between the mobile node and the first mobile agent.

Mobile node, mobile agent and network system

A packet switch apparatus including a plurality of connecting points, each being coupled to one of a plurality of data processing units, and apparatus for receiving a first packet including identification information of a first data processing unit via a first connecting point. The invention further includes a storage for storing correspondence between the first data processing unit and the first connecting point based on the identification information. Apparatus, responsive to reception of a second packet from a second data processing unit to be transmitted to the first data processing unit, transmits the second packet to the first data processing unit via the first connecting point based on the correspondence stored in the storage.

System for and method of exchanging server data in packet unit

Mobile node, mobile agent-and network system

A server system constructed by a network using a known PBX in such a manner that information processing terminal equipment and server devices are held in normally-used extensions of the PBX together with other terminals such as telephones, facsimiles, etc. Logical channel numbers of packet links between the PBX and the information processing terminal equipment are assigned to electrically-connected server devices in association with each other and sent to users. The users sends server use data to corresponding destinations by data packets to which the logical channel numbers are applied. The PBX performs a packet exchange process such that the logical channel numbers are respectively associated with physical addresses of the server devices. If the PBX regards the users as improper users, then it does not inform the users of the logical channel numbers. When a logical channel number of a server device used at a user desire is recognized, the user can utilize the PBX server system even if a proper user does not know a physical address of the server device.

The network connecting apparatus implements an address resolution control method in conjunction with a switch on a network having a plurality of sub-nets within a single physical segment. The network connecting apparatus includes a switch 20 constituted by port control units 31 through 34, a switch control unit 35, a managing unit 36 and an address managing table 37. The switch 20 is supplemented innovatively with an address resolution control unit 47 and with an ARP request packet detecting unit 382 in a destination port discriminating unit 38 of the switch control unit 35.

Network connecting apparatus

An internetworking apparatus for interconnecting a plurality of networks, having forwarding sections corresponding to interfaces of the networks, each including a processor for performing packet forwarding processing and a statistics unit for collecting processing time statistics of the processor. An adjusting section connected to all the forwarding sections through a bus instructs each processor to change a program to be executed thereby based on the processing time statistics reported by each processor so as to balance processing loads on the respective processors.

Internetworking apparatus for load balancing plural networks

An ISDN communication controller or a multi-circuit communication controller is implemented in a sheet of communication adapter board. For each channel or circuit, a dedicated subprocessor section conducts communication processing. In each subprocessor section, a local bus is disposed to connect a CPU, a serial controller, and an RAM. In a main processor section controlling the subprocessors, a local bus is employed to connect a CPU, an RAM, and an ROM. In a system processor section exclusively achieving information processing, a system bus is used to connect a CPU and a main memory. The local buses are connected via respective controllers to an upper-level local bus. A shared RAM is connected via a controller to the upper-level local bus and the system bus. The controllers of the subprocessor sections translate addresses to be outputted from the main processor section to the upper-level local bus to supply translated addresses to the respective local bus.

Growing community of inventors

Yokohama, Japan

Tetsuo Oura