Fujitsu Corporation

Reiko Furuya

Kenji Tanaka

Osamu Sekihata

Ryuji Hyodo

Hiroyuki Hatta

Katsumi Oomuro

Susumu Eda

Tetsuo Nishino

Eisuke Iwabuchi

Kiyotaka Shikata

Toshimitsu Ohba

Norihiro Yoneda

Hirokazu Minou

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 keep call back device for connecting calls between subscribers includes a first call establishing portion for establishing a first call by connecting a call received from a calling terminal to a called terminal when it recognizes the call from the calling terminal which is able to respond to a call from one terminal without ending communication with another terminal during communication with another terminal, a second call establishing portion for establishing a second call by placing a call to the calling terminal after the first call has been established, and a call releasing portion for releasing the first call by disconnecting the same when the second call is established.

Keep call back device

A fault notifying system notifies a fault in an asynchronous transfer mode (ATM) network to at least one data terminating equipment (DTE). The fault notifying system includes a network interface coupled to the ATM network for outputting an alarm indication signal (AIS) when a fault is generated in the ATM network. An ATM crossconnect part generates an AIS cell having a predetermined signal format in response to the AIS. An adaptation layer processing part forms ATM cells, disassembles ATM cells and outputs a data circuit-terminating equipment not ready (DNR) in response to the AIS cell. A terminal interface coupled to the DTE notifies the fault in the ATM network to the DTE in response to the DNR. The AIS cell has a cell format identical to an ATM cell format but has predetermined information in a specific part of the ATM cell format to distinguish the AIS cell from the ATM cell.

Fault notifying system for asynchronous transfer mode communication

An ATM exchange system includes a unit for detecting management cells from among multiplexed input ATM cells, and a path creating unit dedicated to the detected management cell. The path creating unit is activated each time the management cell detecting unit detects the management cell, and thus the management cell is transferred to the corresponding outgoing line without loss in the exchange, and can be transferred thereto before a user ATM cell.

ATM exchange system

Growing community of inventors

Kawasaki, Japan

Reiko Furuya