Fujitsu Corporation

Kazuhiro Ozawa

Tatsuya Nagata

Kenichi Akita

Yuko Tangiku

A method of checking communication-path data in a system, in which a router connecting first and second networks operating on different protocols is connected to a switch of the second network, includes the steps of changing the router and the switch from a normal mode to a test mode, checking consistency between router communication-path data controlled by the router and switch communication-path data controlled by the switch by sending the router communication-path data to the switch during the test mode, and checking communication between the router and the switch by sending cells from the router to the switch and returning the cells from the switch to the router during the test mode.

Checking communication-path data in MPLS communication scheme

A communication route monitoring system monitors a communication route in an ATM network with OAM loopback cells. The communication route monitoring system has a first OAM loopback cell delivering unit disposed in one of the communication devices which performs a network management function, a first returning and relaying unit disposed in each of the communication devices, and a communication route recognizing unit disposed in the communication device which performs the network management function. The first OAM loopback cell delivering unit delivers a first OAM loopback cell for confirming a communication route to a route terminal point. The first returning and relaying means returns the first OAM loopback cell upon reception of the first OAM loopback cell, together with its own location identification added thereto, to a source, and relays the received first OAM loopback cell to a next one of the communication devices. First OAM loopback cells together with added location identifications of the respective communication devices are returned to the communication route recognizing unit. The communication route recognizing unit analyzes the first OAM loopback cell returned from each of the first returning and relaying units to recognize a status of the communication route.

ATM network communication route monitoring system

In an ATM switch, after a communication path is properly set up, a continuity test is performed by passing an OAM cell through the communication path before initiating the transmission of user cells. After the transmission of user cells is initiated, a loopback test is performed by periodically inserting an OAM cell in a user cell flow. When a fault condition is detected as a result of the OAM cell loopback test, a peak cell rate environment is created by adding OAM cells to the user cells for a limited period of time, and communication quality is measured under the thus created environment. When a point-to-multipoint connection with a plurality of leaf points is set up, correspondence between each leaf point and a physical connection point is recorded in a table. When a loopback test to a specific leaf point is requested from a maintenance console, an ATM line control unit corresponding to the specific leaf point is determined by referring to the table, and transmission of the OAM cell is allowed only through that ATM line control unit. In this way, an OAM cell loopback test to a specific leaf point can be accomplished.

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Nagoya, Japan

Kazuhiro Ozawa