Kddi Corporation

Ntt Electronics Corporation

Nippon Telephone and Telegraph Corporation

Jun Endou

Daisuke Arai

Akira Idoue

Takeshi Kouyama

Makoto Nakamura

Masatoshi Tobayashi

Yoshikazu Urabe

Yohtaro Umeda

Kenji Hori

Hatsushi Iizuka

Yuji Akatsu

Yuuki Imai

Eiji Hyodo

A gain switching determination circuit () compares/determines a comparative input voltage (Vc) from an inter-stage buffer () with a first hysteresis characteristic, and outputs a gain switching signal (SEL) based on the comparison/determination result to first and second transimpedance amplifier core circuits (), thereby switching the gains of the core circuits. This obviates holding a comparison input voltage with long response time in a level holding circuit for gain switching determination, which allows instantaneous gain switching determination and instantaneous response corresponding to burst data.

Transimpedance amplifier

A switchhaving a tag VLAN function includes a plurality of physical ports P, P. . . , and adds an ID tag unique to each physical port to the header of a packet received by the physical port and sends the packet, and on the other hand, refers to an ID tag attached to a packet received from a GWand sends the packet to a physical port corresponding to the ID tag. The GWsearches for a server address corresponding to the ID tag attached to the packet received from the switchand modifies a destination address of the packet into the server address. In addition, the GWattaches an ID tag corresponding to a source address of the packet received from the shared serverto the received packet, and modifies the source address of the packet into a GW address.

Communication control method and system

An administrator(2) registers configuration files of compliant equipmentand noncompliant equipmentand a configuration script into a management server, and (3) sends the network equipment to a user. When the userconstructs the local networkby connecting the network equipment and turns it on, (4) a configuration request message is transmitted from the compliant equipmentto the management server. (5) The management serverreplies with the configuration file of the compliant equipment, the configuration file of the noncompliant equipment, and the compliant script to the compliant equipmentin response to the configuration request. The compliant equipment(6) registers its own configuration file received from the management serverinto itself, and then (7) configures the configuration file of the noncompliant equipmentinto the noncompliant equipment by executing the received configuration script.

Network configuration method and system

Growing community of inventors

Tokyo, Japan

Jun Endou