Fujitsu Corporation

Koichi Saiki

Takashi Okuda

Youichi Konuma

Yoichi Konuma

Takashi Fukagawa

Masashige Kawarai

Takanori Sasaki

Junichi Shimada

Noboru Iwabuchi

Akira Miyasaka

Hironori Mieno

Jyunichi Shimada

Toshihiko Tanegashima

Yukihiro Hayakawa

The present invention discloses a method including the steps of a) confirming the status of a path corresponding to each node apparatus in the ring network by using a predetermined control information that includes a function of adding/deleting a predetermined path on a physical layer, b) instructing each node apparatus to add/delete the predetermined path by using the predetermined control information when the status of the path corresponding to each node apparatus is confirmed to be normal, c) reporting completion of the addition/deletion of the predetermined path to each node apparatus by using the predetermined control information when the addition/deletion of the predetermined path is adequately performed by each node apparatus, and d) reporting the addition/deletion of the predetermined path to a ring application function included in the ring application of the data link layer when the completion of the addition/deletion of the predetermined path is adequately reported by each node apparatus.

Method for increasing/reducing band data rate of ring-based network and node apparatus of the ring-based network

A transmission device is connected to a layerswitch through a transmission path at one side, and to a relay transmission path at the other side. The transmission path includes a transmission path of a active system and a transmission path of a stand-by system. When failure occurs in the transmission path of the active system, the transmission device forcibly shuts down the transmission path of the active system upon detection of link down, to stop packet transmission, and causes the layerswitch to perform MAC address flush. The transmission device then switches the transmission path of the stand-by system to the active system, and transmits packets through the transmission path that has become the active system as a result of switching. The layerswitch performs MAC address learning to set a port, thereby maintaining communication even after occurrence of the failure.

Transmission device and redundant configuration between transmission device and layer 2 switch

An ADM device which is capable of performing LCAS functions, configures a first communication network, and is connected to another ADM device which is connected to a second communication network, comprising an SDH interface for connecting to the other ADM device by SDH connection, an H4 byte monitoring means for monitoring the H4 byte of POH in the SDH interface, an LCAS control information acquisition means for acquiring LCAS control information from the H4 byte monitored by the H4 byte monitoring means, and an LCAS control information transmission means for transmitting LCAS control information acquired by the LCAS control information acquisition means to the other ADM devices, thereby providing an ADM device and signal transmission method which comprises a function for efficiently handling sharp variations in traffic, promotes work efficiency of transmission capacity increase/decrease speed within ADM systems, and actualizes the facilitation of management.

ADM device and signal transmission method

A network device provided with an Ethernet interface for interconnecting with another network device by auto negotiation, the network device comprising a link establishing function unit compulsorily establishing a link with the other network device and an on/off setting function unit setting the function of the link establishing function unit on or off and the link establishing function unit being comprised of a data transmission suppressing unit for suppressing the transmission of user data to the other network device until the sequence based on the auto negotiation is finished, whereby the problem of connectivity where the sequence of the auto negotiation repeats and no link can be established is solved.

Network device provided with ethernet interface

In an L2 switch having a VLAN function for configuring a layer 2 network in a star topology, a mesh topology, a ring topology, or the like, a VLAN functional portion maps a frame to a predetermined VLAN, a frame classifying portion assigns to the frame a first tag indicating a priority, and a policing portion assigns to the frame a second tag indicating whether or not the frame can be discarded. Also, an OAM monitor inserts a monitoring frame to the VLAN.

L2 switch

A video-conference network managing system manages a video-conference network, the video-conference network comprising a plurality of video-conference terminal apparatuses connected with one another via a network so as to enable a video conference to be held. The managing system comprises a site managing unit for managing each video-conference terminal apparatus of the plurality of video-conference terminal apparatuses. The system further comprises a schedule managing unit for managing a schedule concerning the video conference. The system further comprises a transmitting/reception control unit for sending, if appropriate, a command to the plurality of video-conference terminal apparatuses in accordance with the schedule concerning the video conference. The system further comprises an alarm collecting unit for collecting alarm information, if any, from the plurality of video-conference terminal apparatuses.

Video-conference network managing system having function for managing

In a multimedia multiplexer device coupled to communications devices and a line terminating unit, a first unit provides a plurality of predetermined interfaces suitable for the communications devices and the line terminating unit. A second unit receives control signals from the communications devices and the line terminating unit and identifies parameter information concerning suitable interfaces from the control signals. A third unit selects the suitable interfaces from the plurality of predetermined interfaces in accordance with the parameter information identified by the second unit, and makes the first unit provide the suitable interfaces from the plurality of predetermined interfaces.

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Kawasaki, Japan

Koichi Saiki