Fujitsu Corporation

Osamu Sekihata

Kenji Tanaka

Ryuji Hyodo

Hiroyuki Hatta

Susumu Eda

Katsumi Oomuro

Reiko Norizuki

Tetsuo Nishino

Kiyotaka Shikata

Reiko Furuya

Toshihiro Ishida

Naofumi Kobayashi

Eisuke Iwabuchi

Susumu Tominaga

Toshimitsu Ohba

Kazumasa Kuroshita

Masataka Yamada

Hiroomi Shinha

Nakaba Yuhara

Tetsumi Ichikawa

Shiro Mori

Toshihiko Inoue

Hirokazu Minou

Katsumi Oomura

Ikutaro Tsujikado

Hironobu Michiya

Hajime Fukushima

A communication system includes a station-side terminal apparatus and multiple subscriber-side terminal apparatuses connected to the station-side terminal apparatus. The station-side terminal apparatus is configured to, in response to receipt of a packet from a subscriber-side terminal apparatus, a packet indicating whether data distribution is required, identify the subscriber-side terminal apparatus that has transmitted the packet, and transmit a packet indicating an address for which whether the transfer of distribution data is required is designated to the subscriber-side terminal apparatus based on whether data distribution is required. Each subscriber-side terminal apparatus is configured to, in response to receipt of a distribution packet, if the distribution packet has the address for which whether the transfer of distribution data is required is designated, transfer the distribution packet to host apparatuses accommodated thereto or prohibit the distribution packet from being transferred to the host apparatuses accommodated thereto.

System and apparatus thereof for Ethernet PON communication

A fast ring switchover is enabled in packet level processing at the time of ring configuration, and as a result, a system switchover function can be implemented in an Ethernet switch or the like by a ring switchover method in a network constituted of layer 2 switches connected in a ring shape, each layer 2 switch having a path control function and a failure detection function. The ring switchover method includes the steps of providing in each layer 2 switch an address learning table in which a Media Access Control (MAC) address and a corresponding port are stored; on detection of a link failure between mutually neighboring layer 2 switches, transmitting a failure notification frame packet from each neighboring layer 2 switch; and in the layer 2 switch having received the failure notification frame, recording a Media Access Control (MAC) address of said layer 2 switch into the failure notification frame, and transferring the failure notification frame to a neighboring layer 2 switch.

Ring switchover method

A frame forwarding installation on the side of a transmitting terminal refers to a header of a received frame and determines whether a host application is a real-time application. If the application is a real-time application, the received frame is sent to a plurality of paths in the direction of a destination. When a frame received from a path is transmitted to a destination terminal, a frame forwarding installation on the side of the destination terminal stores the identifier of this frame in a storage unit and, if a frame then newly arrives from a path, determines whether the frame identifier of this frame has been stored in the storage unit. If the newly arriving frame has been stored, it is regarded as being a frame already received and is discarded. If the newly arriving frame is not a frame that has already been received, the received frame is transmitted to the destination terminal and the identifier of this frame is stored.

Frame forwarding installation

In a relaying apparatus detecting a congested state and performing a flow control, an output buffer using an up-link or a stack-link is monitored. When the up-link or the stack-link is in a congested state, a transmission restriction is imposed on a port which is a transmitting source of a corresponding frame. Furthermore, when a plurality of relaying apparatuses are connected through stack-links, the relaying apparatus having the up-link detects the congested state of the up-link and notifies a second relaying apparatus of the congested state to make a transmission restriction.

Relaying apparatus

A network address supply system includes terminal equipments, a server, and a switching HUB to which the terminal equipments and the server are connected via communication lines. Each terminal equipment includes an address supply requesting unit. The switching HUB includes interfaces, a first line data storing unit, and a communication line control unit that when one of the interfaces receives an address supply request broadcast packet from one of the terminal equipments, transmits the address supply request broadcast packet to only an interface corresponding to the interface information stored in the first line data storing unit. The server includes a network address storing unit and an address supplying unit that when receiving the address supply request broadcast packet, broadcasts an address broadcast packet containing an unused network address stored in the network address storing unit as a response packet to the address supply request broadcast packet.

Network address supply system for transmitting an address supply request to only a server

A mobile user station periodically searches for a connectable access point and stores the address of a connectable access point that has been found in a master-station management table. When the mobile user station moves from one cell to another under these conditions, the state of communication with the old access point deteriorates. When the state of communication with the old access point deteriorates to such a degree that it becomes necessary for the mobile user station to connect to a new access point, the mobile user station sends a connection request to the access point stored in the master-station management table and performs communication via the new access point. As a result, when connection to a new access point becomes necessary owing to movement of the mobile user station between cells, the changeover between access points can be performed quickly without searching for an access point.

Means for maintaining connectable access points owing to movement of a

An ATM multiplex transmission system including AAL processing units, an ATM cross connection processing unit, and a plurality of lines connected to the same, wherein the system has test equipment formed in it, the test equipment being formed as a particular cell generating unit and a routing information setting unit in at least one of the line corresponding points which the ATM cross connection processing unit has at the portions connecting with the lines. When a routing test is performed in the system, the VPI and the VCI designating the route are given from the outside as the routing information.

ATM multiplex transmission system having test equipment

A master station detects the strength of a signal received from a slave station and, on the basis of the signal strength of the receiving signal, decides a transmission timing at which frame contained in the signal is to be sent to a backbone LAN. When the transmission timing decided arrives, the master station determines whether a carrier is present on the backbone LAN. The master station discards the frame from the slave station, and therefore does not send it, if the carrier is present. If the carrier is not present on the backbone LAN, the master station sends the frame to the backbone LAN. Thus, interference between adjacent cells does not occur even when each of a number of master stations send signals to and receive signals from a slave station by using the same channel.

Wireless LAN system

In a congestion control system for an interface between a PBX and an ATM multiplexing transmission unit connected to a network via an ATM transmission line, a congestion detecting unit detects a congested state in which the ATM transmission line is congested with traffic. A control unit inhibits a call from the PBX from being sent to the ATM transmission line via the ATM multiplexing transmission unit when the congestion detecting unit detects the congested state.

System and method for controlling interface between PBX and ATM

An ATM multiplex transmission system including an ATM adaptation layer (AAL) processing unit, an ATM cross connection processing unit having a switch and FIFO memories connected to the incoming and outgoing sides, and dummy load cell generating units which forcibly write dummy load cells in the incoming FIFO memories or outgoing FIFO memories, the writing of the dummy load cells being used to execute a load test on the FIFO memories.

A bus load distributing method suitable for data communications equipment and a bus switching control device for data communications equipment. The data communication equipment includes plural buses, a bus connecting unit for interconnecting the plural buses, and a control unit for connecting physically and selectively each module to one among the plural buses. The control unit connects plural modules to a bus to recognize, distribute and reduce the load on the bus. The control device also switches a bus to be connected in accordance with the traffic of each module to optimize the bus load.

Bus load distributing method suitable for data communications equipment

A LAN-WAN-LAN communication method and apparatus for performing communication between a LAN on a transmitting side and a LAN on a receiving side via a wide area network within limits of an allocated band includes a demultiplexer/multiplexer unit for demultiplexing data, which has been received from the LAN on the transmitting side, into data constituting the smallest units of information and transmitting this data via a plurality of lines. Then, data, which is sent to the receiving side via each line, is multiplexed on the receiving side and the multiplexed data is sent to the LAN on the receiving side. A traffic monitoring unit is provided for monitoring traffic between LANS. A band is obtained, which is required for communication between LANs based upon the traffic. Communication between LANs is performed by increasing, decreasing or maintaining the number of lines, which are used in communication between LANS, based upon the obtained band.

LAN-WAN-LAN communication method, and apparatus for LAN-WAN connection

A method for supervising and controlling ATM traffic, which uses idle cells transferring traffic information to manage a network, comprising steps of a first step for mapping traffic information in the information field of an idle cell and transferring said idle cell to other communication nodes, a second step for performing the operation of traffic control in accordance with the contents of said traffic information included in said idle cell on the receiving side of said other communication nodes, and a third step for assembling a new idle cell including said traffic information of received idle cell and/or new traffic information on said receiving side of communication nodes and transferring said new idle cell from said receiving side of communication nodes to other communication nodes.

Apparatus and a method for supervising and controlling ATM traffic

An apparatus for supervising and controlling ATM traffic, and which collects traffic information, including a cell detecting unit for outputting a cell detecting signal whenever detecting a user information cell flowing through an ATM switch unit, an idle cell detecting unit for outputting an idle cell detecting signal whenever detecting an idle cell flowing through an ATM switch unit, a cell counting unit for counting the cell detecting signals output from the cell detecting unit, an idle cell counting unit for counting the idle cell detecting signals output from the idle cell detecting unit, an idle cell rate detecting unit for detecting an idle cell rate from both counts output from the cell counting unit and the idle cell counting unit at regular intervals, and a control unit for performing the operation of traffic control in accordance with the idle cell rate provided from the idle cell rate detecting unit at regular intervals.

An amount-of-data identifying portion identifies the amount of data transmitted by referring to a specific portion in the upper layers of the information transmitted from the terminal of a LAN, and a bandwidth control line monitor portion calculates the band which is necessary for communication. Communication between LANs is executed through the number of wide area network interface portions which is determined on the basis of the calculated band. In the case that the communication is performed after securing the band corresponding to the traffic characteristics (transfer speed, etc.) declared to the network, the amount-of-data identifying portion identifies the amount of data transmitted by referring to a specific portion in the upper layers of the information transmitted from the terminal of a LAN, a traffic characteristics calculator calculates the traffic characteristics on the basis of the amount of data transmitted, a traffic characteristics declaring portion declares the calculated traffic characteristics to the network, and the network communicates on the basis of the declared traffic characteristics.

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Kawasaki, Japan

Osamu Sekihata