Hitachi, Ltd.

Hitachi Microsoftware Systems, Inc.

Other

Hitachi Information Technology Co., Ltd.

Hitachi Microsofyware Systems, Inc.

Naomichi Nonaka

Keiichi Nakane

Hiromichi Itoh

Tadashi Kuwabara

Hiroyuki Koreeda

Yoshinori Watanabe

Kazuhiro Kusama

Kiyoshi Masuda

Kazunari Suzuki

Hideki Kuwamoto

Minoru Koizumi

Yoshiyuki Nakayama

Machiko Asaie

Masaki Fujiwara

Shigeki Taniguchi

Hideaki Ishida

Yukihiro Takatani

Koichi Kimura

Susumu Matsui

Hiroaki Aotsu

Hiroshi Furukawa

Naoya Ikeda

Masato Hayashi

Shigeru Miyake

Satoru Tezuka

Kenichi Kihara

Toru Horimoto

Masaki Kawase

Yujiro Tatsuno

Katsumi Hanashima

Emiko Yanagisawa

Satoru Matsumura

Reiko Iwasaki

Ryoji Higashizono

Communication node including a transmission equipment which communicates user data with transmission equipment of an adjacent node, and a controller which communicates a message with a controller of the adjacent node and which manages the transmission equipment of its own node, wherein: a controller of the node detects existence or nonexistence of fault of a controller of the adjacent node on the basis of situation of receiving a message sent from the controller of the adjacent node; when the controller of the node detects the fault of the controller of the adjacent node, the controller of the node issues a state reference notice to a transmission equipment of its own node and checks existence or nonexistence of fault alert detection; in a case where the fault alert detection of the transmission equipment of the node does not exist, the controller of the node maintains a path state of the node.

Communication node and communication system

An optical multi-drop path is set to a downstream direction, an optical path between adjacent nodes is set to a upstream direction, a packet sorting unit is provided for appropriately controlling packet streams in the downstream direction and upstream direction, and one-to-one or one-to-N communication can be performed not only between servers and clients but also between the clients even when a multi-drop transmission is used in the downstream direction.

Packet transfer device

Power consumption on GMPLS controlled networks can be reduced by cutting power consumption on spare paths that are not normally used. To achieve power consumption reduction, in the path setting process, a path is calculated while taking the power saving capability of each interface into account, and the applicable interface is set to the power-saving state when setting the spare path. When the spare path was set to the operating state, then the power-saving state on the applicable interface was canceled so that interface could operate normally.

Network system

In a network wherein a data plane for communicating user data, and a control plane for managing data forwarders are configured of different media, the path teardown of the data plane which is forwarding the data is prevented when a fault has occurred in only the control plane. When the GMPLS controller of the control plane has detected refresh timeout with respect to an adjacent node (in FIG.), it checks whether or not a transmission equipment corresponding to a faulty controller has a fault (), and it maintains a path state () in a case where the fault is limited to the control plane. Thus, the exchange of refresh messages with the adjacent node is continued without cleaning up the resources of the transmission equipment (through).

In a L2VPN, where Ethernet frames are encapsulated and transferred, when an edge node disposed at an entrance of the L2VPN encapsulates an Ethernet frame, the data type of the payload of the Ethernet frame is checked. If the payload data type includes time-to-live (TTL) information, whether to encapsulate or discard the frame is judged according to the TTL value. One material for judging whether to discard the frame is a condition that the TTL value is larger than '1' and smaller than a predetermined threshold.

Packet transfer method and node apparatus

When protection processing is applied after a fault in the optical switching unit while the path control unit is restarting. In network systems comprising a path control unit for setting the paths, and a data transmission unit coupled to the path control unit; the data transmission unit changes the path information, stores path information before and after the fault was detected, and transmits the path information from before or after fault detection to the path control unit, and decides either of the transmitted path information based on an internal status; and the path control unit stores the path information sent from the data transmission unit, and after restarting, receives path information from the data transmission unit and, acquires path information stored in the path control units controlled by the adjacently connected data transmission units and is restored to operation with path information from before restarting.

Network system of recovering routing information

An information processing apparatus having a resume function which can maintain the security even when a plurality of users commonly use the apparatus. A work state at a power-off time of the apparatus is preserved together with a work state name including a user's ID in a different area in a plurality of preservation areas for resume function on a main memory for each user. When a power source is again turned on, data in the preservation area corresponding to the user's ID is used to reproduce the work state of the user at the power-off time. The work preservation areas can be provided on a file server apparatus in a network not needing battery back-up. When the information processing apparatus is used, a work state at a power-off time can be independently preserved and reproduced for each user.

Information processing apparatus with resume function and information processing system

A GSM network () includes a base station (). A first mobile terminal () is outside a region of coverage. Using Bluetooth network, a second terminal () relays signals between the first terminal and the base station. The second terminal is awarded credit for relaying the signals.

Mobile communication network using mobile station with relay-function and method for rewarding relay activities of mobile station

A system for use with communications according to TCP, or a similar protocol, includes a sender host, one or more routers, and a destination host. Each router includes means for generating acknowledgement packets and translating addresses associated with data packets. When a data packet is received by a router, an acknowledgement packet is returned with a source address corresponding to the router and a destination address corresponding to the sender host. The sender host perceives the acknowledgement packet as having been sent by the destination host. As the acknowledgment packet is sent by the router, and not the destination packet is sent by the router, and not the destination host, this system allows acknowledgment packets to be received on a shorter timescale, reducing the effects of a link delay. Although the route between the sender host and the destination host is divided into multiple connections, the hosts perceive a single, conventional connection.

Performance enhanced TCP communication system

A communication system using asymmetrical paths for performing asymmetrical routing using unidirectional paths for unidirectional packet communication without changing existing protocols in network systems configured for bidirectional packet communication using bidirectional paths. The communication system includes a receiver gateway installed in a satellite receiver station for performing address substitution on a packet transmitted from a personal computer (PC) to a server via an Internet network, and a transmitter gateway installed in a satellite transmitter station that receives the substituted packet and transmits the substituted packet to the server. Particularly, the transmitter gateway transmits the substituted packet to the PC from the server by transmitting the substituted packet to the receiver gateway by way of a satellite. The receiver gateway sends the substituted packet to the PC.

Communication system for communications devices utilizing asymmetrical paths and communications method utilizing asymmetrical paths

Growing community of inventors

Kawasaki, Japan

Naomichi Nonaka