Alcatel Canada Inc.

Denny L S Lee

Jason T Sterne

David Walter Carr

Tom Edward Davis

Sudhakar Ganti

Stanko Vuleta

Apparatus and method for shaping ATM cell traffic emitted onto a virtual path connection in an ATM network are described. Component virtual channel connections are arbitrated at an aggregation point utilizing an arbitration technique. The technique provides both virtual path shaping and controllability of underlying virtual channel connections with an improved fairness performance amongst all the aggregating virtual channel connections.

Virtual connection shaping with hierarchial arbitration

A method and network element for feedback control for adjusting a rate of message transmission over a connection in a network is provided. The connection comprises a source and destination linked by forward and backward message paths. The source has instructions for setting a message transmission rate for the connection provided by feedback messages received, each containing an explicit rate of transmission. The method comprises steps: receiving feedback messages from the backward path; extracting an explicit rate being carried by each feedback message received; storing each feedback message received in a queue; retrieving a stored feedback message and, substantially when it is transmitted, marking it with an explicit rate determined from an extracted explicit rate pertaining to another message received more recently and a rate determined from a state of congestion of the network element; and externally transmitting the feedback message over the backward message path once so marked.

ER information acceleration in ABR traffic

There is provided a method and device for measuring a rate of message element traffic over a message path in a communications network. The path includes at least one connection and is associated with a maximum rate of transmission. The path is periodically polled for transmission of a message element, the polling being performed at a polling rate associated with polling intervals which are at least as frequent as the maximum rate of transmission. If transmission of a message element is detected during a polling interval, a running count of such detection is incremented, the running count of detection being associated with the connection over which the message element was detected. If transmission of a message element is not detected, a running count of such non-detection is incremented, the running count of non-detection being associated with inactivity of the message path. During each polling interval, an oldest stored value is retrieved from a memory which includes a preselected number of stored values that correspond to an equal number of most recent sequential events of detection and non-detection. Each stored value which represents an event of detection corresponds to an identifier denoting the connection over which the message element was detected. Each stored value which represents an event of non-detection corresponds to an identifier denoting inactivity of the message path. Following retrieval during each polling interval, the running count of detection associated with the connection corresponding to the identifier of the retrieved value is decremented if the retrieved value represents an event of detection. The running count of non-detection is decremented if the retrieved value represents inactivity. The retrieved value is thereafter replaced with a value corresponding to an identifier which denotes the connection over which the message element was detected if transmission was detected. Otherwise the retrieved value is replaced in the memory with a value corresponding to an identifier which denotes inactivity if transmission was not detected. The foregoing steps are repeated for so long as the measurement is undertaken. The rate of message element traffic over a connection of the message path is proportional to the running count of detection associated with the connection.

Rate monitoring of connections in a communications network using history buffer

A device and algorithm for fairly allocating available bandwidth between contending connections at a contention point in a data network. The allocation is based on global queue size at the contention point and a weighted value assigned to the data traffic. The device and algorithm find particular application in an ATM network which supports the available bit rate (ABR) service category.

Fair share bandwidth allocation algorithm and device

A system and method for calculating a quotient based algorithm without using a division operation. The quotient based algorithm is used to provide explicit rate values to ABR cell traffic in an ATM network. A look up table is used to obtain reciprocal values required to process the algorithm.

Calculation of quotient-based explicit rate algorithm for ABR traffic

A calendar based ATM cell scheduling device is used to maintain accurate shaping of cell streams in order to satisfy traffic management guarantees. In certain applications cell insertion may occur downstream of the scheduling device, potentially violating traffic descriptors. The correction means provided by the present invention allows for such downstream cell insertion without violating guarantees by generating a calendar slip in the scheduling device.

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Kanata, Canada

Denny L S Lee