Nortel Networks Corporation

Avaya Inc.

Eric Haversat

Victor Firoiu

Thomas O Holtey

Xiaohui Zhang

Gregory Edward Lund

Carl Keene

Richard Lacerte

Multiplexed traffic in a system where the maximum rate of all inputs exceeds the maximum rate of the output is processed via a separate queue for each input, and at any given forwarding clock cycle the earliest enqueued packet is forwarded via the output. In the event of congestion, a proportionally equal number of packets are dropped from each queue, where proportional equality corresponds to the number of packets dropped per number of packets enqueued. One implementation associates a time-stamp with each enqueued packet to indicate the time of enqueing relative to other enqueued packets. At any given forwarding clock cycle, the packet with the earliest time-stamp is forwarded.

Traffic multiplexing using timestamping

A Balanced Packet Transmit Opportunity (BPTO) mechanism allows balanced bandwidth traffic to be serviced while still maintaining the service levels desired for high priority traffic. The above embodiment achieved the result by distinguishing both queue types and slot style types, and performing selections differently depending upon the relative styles of the queues and slots. This arrangement provides a number of advantages. Because the selection method is fast and relatively simple to implement, a large number of queues may be integrated into the decision process while maintaining a desired output bandwidth. In addition, the selection process provides a flexibility, allowing multiple traffic shaping considerations to be modified during operations to support changing network requirements. In addition, the selection process provides a flexibility, allowing multiple traffic shaping considerations to be modified during operations to support changing network requirements.

Queue scheduling with priority and weight sharing

A feedback output queuing system, apparatus, and method controls the rate at which packets are forwarded from the ingress ports to a particular output queue over the switching/routing fabric based upon the level of congestion at the output queue. The output queue is monitored and the level of congestion at the output queue is determined based upon a predetermined congestion determination mechanism. An ingress forwarding scheme is determined based upon the level of congestion at the output queue. Information is forwarded from the ingress ports to the output queue based upon the ingress forwarding scheme.

Feedback output queuing system, apparatus, and method

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Tewksbury, MA, United States of America

Eric Haversat