Nortel Networks Corporation

Avaya Inc.

Xiaohui Zhang

Victor Firoiu

Eric Haversat

Ikjun Yeom

Thomas O Holtey

Gregory Edward Lund

Carl Keene

Richard Lacerte

Yang Guo

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 model is given for performance evaluation of IP computer networks that are dominated by congestion-controlled traffic. The model includes heterogeneous TCP flows, UDP flows, short-lived TCP flows, and TCP flows in a differentiated services network. The performance of large-scale networks is estimated where flows may encounter multiple congested links.

Performance evaluation and traffic engineering in IP networks

Modeling link throughput in IP networks

An apparatus and method of managing received packets to be transmitted from a network device stores the received packets on one of two different buffers. In particular, the received packets are one of a first type of data packet and a second type of packet. Each one of the first type is stored in a first buffer having a first drop function, while each one of the second type is stored in a second buffer having a second drop function. Each respective drop function specifies a packet drop rate as a function of the average number of packets in its respective buffer. The first drop function has a first average drop rate over a specified time interval, while the second drop function has a second average drop rate over the specified time interval. The first average drop rate and the second average drop rate have a predefined relationship. Accordingly, if the two drop rates do not comply with the predefined relationship, then at least one of the two average drop rates are modified.

Method and apparatus of processing packets having varying priorities by adjusting their drop functions according to a predefined fairness relationship

Growing community of inventors

Billerica, MA, United States of America

Xiaohui Zhang