US 2002/0163914 A1 · Network switch port with weighted random early discard

Abstract

A network switch port receives, stores and then forwards incoming cells. The network switch assigns each incoming cell to one of a set of flow queues, each of which is allotted a portion of space in a cell memory. The switch port periodically computes a average of the number of cells assigned to each flow queue stored in the cell memory during a preceding period, and assigns a discard weight to each incoming cell that is a function of the amount by which the average for the cell's assigned flow queue exceeds a threshold level. The switch port randomly discards incoming cells assigned to the flow queue with a probability that increases with the incoming cells' assigned weights. The switch port stores incoming cells that are not randomly discarded in the cell memory and later forewords them from the cell memory.

Claims20

Dependent claims

A method for a network switch port for receiving and storing data included in incoming packets and then forwarding the data from the network switch port, the method comprising the steps of:

a. receiving each incoming packet and generating a cell sequence corresponding to the incoming packet, wherein each cell of the cell sequence packet contains a separate portion of the data included in the incoming packet;
b. making a determination with respect to at least one cell of each cell sequence generated at step a as to whether to discard the cell or to store the cell in a memory, and then one of storing or discarding the cell in the memory in accordance with the determination;
c. reading cells out of the memory and forwarding them from the network switch port;
and
d. repetitively generating an estimate of an average number of cells stored in the memory during a period immediately preceding generation of the estimate, wherein the determination made at step b is a function of the generated estimate.

2 more elements

An apparatus for receiving, storing and then forwarding data in a plurality of incoming packets, the apparatus comprising:

a memory;
first means for receiving each incoming packet and for generating a cell sequence corresponding to the incoming packet, wherein each cell of the cell sequence packet contains a separate portion of the data included in the incoming packet;
second means for making a determination with respect to at least one cell of each generated cell sequence to whether to discard the cell or to store the cell the memory,
third means for one of storing or discarding the cell in the memory in accordance with the determination made by the second means, and for reading cells out of the memory and forwarding them, and
fourth means for repetitively generating an estimate of an average number of cells stored in the memory during a period immediately preceding generation of the estimate,
wherein the determination made by the second means is a function of the generated estimate.

3 more elements

Dependencies are inferred from the claim text.

Network switch port with weighted random early discard

Life of this patent

Network switch port with weighted random early discard

Life of this patent

Abstract

Claims20