SignaMax 065-7434, Configuration Manual, Page: 479 / 669

111 SIGNAMAX LLC • www.signamax.eu
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Brief introduction to the discarding mode
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Explanation of Commands for configuring discarding mode
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Example of configuration
Overview
A port supports two kinds of discarding mode: Tail Drop and sRED. sRED
is a simple random discarding arithmetic used in the early period. It
discards packets in a color before a queue is full. sRED has two queue
threshold: low threshold and high threshold.
Every time when adding a received port into a queue, the present queue
depth is checked; if the queue depth is lower than the low threshold,
then the packet is added to the queue; if the queue depth is higher than
the high threshold, then the packet is discarded; if the queue depth is
between the low threshold and the high threshold, whether to discard the
packet is according to the configured discarding probability.
The discarding probabilities of the yellow packet and the red packet can
be configured; the value ranges are from 0 to 7.
Discarding probability Corresponding percentage
0 100% (discard whole)
1 6.25%
2 3.125%
3 1.5625%
4 0.78125%
5 0.390625%
6 0.1953125%
7 0.09765625%
Mapping between the discarding probability and the percentage
Commands for Configuring Discarding
Mode
Command Description Config mode
drop-mode {tail-drop| sred red
droprate yellow droprate}
To configure the discarding mode;
if is the sred discarding mode, the
discarding probabilities of two
types of packets (red and yellow)
need to be configured.
config-port-*/*
no drop-mode To cancel the configured
discarding mode and recover to
the default value tail-drop
config-port-*/*
drop-mode
no drop-mode