Patent ID: 7756028

Claim:
A method of synchronizing a packet rate R of a traffic flow at an egress side of a queue in a downstream stage with a packet rate R 1 at an upstream stage, comprising the steps of: continuously assessing the status of said queue during each polling period generated by a polling generator to determine whether the queue is in a starving mode or a satisfied mode; shaping the packet rate at said upstream stage at a rate R 1 higher than the packet rate R at the egress of said queue when said queue operates in the starving mode by not transmitting any backpressure pulses; and shaping said rate R 1 lower than the rate R when said queue operates in the satisfied mode by transmitting a series of backpressure pulses to the upstream stage, wherein each backpressure pulse comprises a predetermined period of time when traffic from the upstream stage is stopped, followed by a predetermined period of time when the backpressure is turned off to allow transmission of packets and said shaping comprises: providing a shaping profile for said traffic flow, the shaping profile containing information for shaping backpressure pulses in accordance with a traffic parameter; shaping backpressure pulses for said traffic flow by determining the period of time when traffic from the upstream stage is stopped and the period of time when the backpressure is turned off to allow transmission of packets; and transmitting a series of shaped backpressure pulses from said downstream stage to said upstream stage.