Oki Electric Industry Co., Ltd.

Kazuyuki Horioka

Satoshi Furusawa

Hideki Ohashi

Haruki Uchida

In a communication network in which a group of connections has an assigned group bandwidth and each connection in the group has a minimum bandwidth, bandwidth usage is controlled by calculating the total current bandwidth allowed to the group, subtracting the total current bandwidth from the assigned group bandwidth, and adding the difference to each connection's current bandwidth allowance to calculate an explicit rate, according to which the connection's bandwidth allowance is controlled. The explicit rate is altered to a minimum explicit rate when, for example, the total bandwidth exceeds the group bandwidth. The minimum explicit rate of each connection is preferably calculated on the basis of the sum of the minimum bandwidths of the active connections in the group. These measures improve the fairness of bandwidth usage control.

Bandwidth control method, cell receiving apparatus, and traffic control system

A cell transmitting device receives cells for transmission to a cell receiving device on a connection in a communication network. The connection has a minimum cell rate, established when the connection is set up. The cell transmitting device measures the input rate of cells to be transmitted on the connection, determines an allowable cell rate on the basis of the input rate and cell rate information supplied by the cell receiving apparatus, and transmits cells within the allowable cell rate. Under certain conditions, such as absence of cell traffic on the connection, the allowable cell rate is set to a lowest cell rate lower than the minimum cell rate, thereby enabling other connections to obtain higher cell rates.

Bandwidth control method, cell transmitting apparatus, and traffic control system

The ATM exchange of the present invention comprises an input line interface and an output line interface. The input line interface comprises an FRM extractor for deciding whether each ATM cell sent from a first communication terminal to a switch is an FRM cell or a non-FRM cell, an FRM cycle monitor for using this decision result to monitor the FRM cell proportion among the ATM cells and deciding whether said proportion is normal or abnormal, and a first cell processor for discarding the non-FRM cells when the proportion is abnormal. The output line interface comprises a BRM extractor for deciding whether each ATM cell sent from a communication terminal to a switch is a BRM cell or a non-BRM cell, a BRM cycle monitor for using this decision result to monitor the BRM cell proportion among the ATM cells and deciding whether said proportion is normal or abnormal, and a second cell processor for discarding the non-BRM cells when the proportion is abnormal. When the FRM cycle monitor decides that the quantity of flow of FRM cells has decreased, the first cell processor discards the non-FRM cells and returns the proportion of FRM cells to its normal state. When the BRM cycle monitor decides that the quantity of flow of BRM cells has decreased, the second cell processor discards the non-BRM cells and returns the proportion of BRM cells to its normal state.

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Chiba, Japan

Kazuyuki Horioka