Random-Detect Discard-Class - Cisco NCS 540 Series Routers Command Reference Manual

QoS Classification Commands

random-detect discard-class

To configure the Weighted Random Early Detection (WRED) thresholds for packets with a specific discard
class value, use the random-detect discard-class command in policy map class configuration mode. To
return the thresholds to the default for the discard class, use the no form of this command.
random-detect discard-class discard-value min-threshold [units] max-threshold [units]
no random-detect discard-class discard-value min-threshold [units] max-threshold [units]
Syntax Description
discard-value
min-threshold
max-threshold
units
Default unit for max-threshold and min-threshold is packets.
Command Default
Policy map class configuration
Command Modes
Command History
Release
Release 6.0
WRED is a congestion avoidance mechanism that slows traffic by randomly dropping packets when congestion
Usage Guidelines
exists. WRED is most useful with protocols like TCP that respond to dropped packets by decreasing the
transmission rate.
When you configure the random-detect discard-class command on an interface, packets are given preferential
treatment based on the discard class of the packet.
When the value of the units argument is packets, packets are assumed to be 256 bytes in size.
Discard class value. The value is 0 or 1.
Minimum threshold in number of packets. The value range of this argument is from 0 to
1073741823 in bytes.
Maximum threshold in number of packets. The value range of this argument is from the
value of the min-threshold argument to 1073741823. When the average queue length
exceeds the maximum threshold, WRED drops all packets with the specified discard class
value.
(Optional) Units for the threshold values. Values can be:
• bytes—bytes
• gbytes—gigabytes
• kbytes—kilobytes
• mbytes —megabytes
• ms—milliseconds
• packets—packets (default)
• us—microseconds
Modular QoS Command Reference for Cisco NCS 5500 Series and Cisco NCS 540 Series Routers

random-detect discard-class

Modification
This command was introduced.
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