Fujitsu Corporation

Kazumasa Sonoda

Shiro Uriu

Naoki Aihara

Nobuhiko Eguchi

Hiroya Kawasaki

Masaki Kira

Tetsuaki Wakabayashi

Hiroshi Ishiwata

Yukinaga Toyoda

Hiroyuki Kudou

Masanobu Furukoshi

In a common buffering device with a simple arrangement, a write address can be efficiently released from a buffer memory upon receipt of a multi-address call. For an ATM cell which is to be transmitted to a specific line, a write address is set in a common buffer memory, and the ATM cell is written at the write address. The ATM cell is read from an address which corresponds to the write address, and is transmitted to the specific line. Then, the pertinent write address is released. In a write table are entered a plurality of multi-address lines across which an ATM cell written at a specific address in the common buffering device can be multicast. Each time the ATM cell is read from the specific address, a designation line for transmission of an ATM cell in a read control table is compared with the multi-address lines set in the write control table. When the lines match, the write address for the ATM cell, which is set in the write control table, is released.

Address release method, and common buffering device for ATM switching system which employs the same method

A switching system in an ATM switching system accommodating an ABR is constructed of an individual units connected to a transmitting terminal or a receiving terminal to implement an efficient bandwidth authorization, and a plurality of intra-system relay devices having transmission allowed rate calculating units. In this switching system, there are separated a transfer of a management cell between the transmitting terminal or the receiving terminal and the individual unit and a transfer of the management cell between the plurality of intra-system relay devices.

Communication controlling apparatus

A system includes a host, first and second devices which operate as an acting device and a standby device, and a simplex unit controlled by the acting device. Each device is provided with a monitoring unit for monitoring the occurrence of failure, means for notifying the other device of a failure in its own device, and active/standby notification means. The active/standby notification means notifies the simplex unit that its own device is acting or standing by when the device becomes the acting device or standby device in response to a command from the host. Upon a failure in the other device when its own device is standing by, the active/standby notification means notifies the simplex unit that its own device is now an apparent acting device. Upon a failure in its own device when its own device is acting, the active/standby notification means notifies the simplex unit that its own device is now an apparent standby device. The simplex unit executes predetermined control upon accepting control data from the apparent acting device.

Apparatus for preventing malfunction at time of duplex unit failure

A method of testing an ATM exchange having a redundant structure that includes an active system and a standby system includes the steps of transmitting a test cell from a testing device to both the active system and standby system, causing the test cell to pass through ATM switches in each of the active and standby systems, returning the test cell that has passed through the ATM switches of both systems to the testing device, and conducting a test of the ACT switches in the active and standby systems by comparing data contained in the transmitted test cell with data contained in a test cell received from the active system or standby system.

ATM exchange and method of testing same

Growing community of inventors

Fukuoka, Japan

Kazumasa Sonoda