Cisco CRS Command Reference Manual page 97

Quality of Service Commands on the Cisco IOS XR Software
Release
Release 3.3.0
Release 3.4.0
Release 3.6.0
Release 3.9.0
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes appropriate task
IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator
for assistance.
WRED is a congestion avoidance mechanism that slows traffic by randomly dropping packets when congestion
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 command on an interface, packets are given preferential treatment
based on the IP precedence of the packet. Use the random-detect precedence command to adjust the treatment
for different precedences.
When the value of the units argument is packets, packets are assumed to be 256 bytes in size.
Task ID
Task ID
qos
Examples The following example shows that for packets with precedence 3, the WRED minimum threshold is 1,000,000
bytes and maximum threshold is 2,000,000 bytes:
RP/0/RP0/CPU0:router(config)# policy-map policy1
RP/0/RP0/CPU0:router(config-pmap)# class class1
RP/0/RP0/CPU0:router(config-pmap-c)#random-detect precedence 3 1000000 2000000
Related Commands
Command
bandwidth (QoS), on page 4
OL-23235-03
Modification
The units argument was added to allow specifying the units of the
thresholds.
The precedence-value min-threshold max-threshold arguments were
deleted from the no random-detect precedence command.
The precedence-value argument can accept up to eight values or reserved
keywords separated by commas.
For the random-detect precedence command to take effect, there is no
longer a requirement to configure the shape average , bandwidth (QoS)
, or bandwidth remaining commands in the user-defined policy map
class.
Description
Specifies the minimum bandwidth allocated to a class belonging to
a policy map.
Cisco IOS XR Modular Quality of Service Command Reference for the Cisco CRS Router, Release 4.0
Operations
read, write
random-detect precedence
91