R3303-HP HSR6800 Routers ACL and QoS Configuration Guide

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• The exponent used for average queue size calculation—The bigger the exponent is, the less
sensitive the average queue size is to real-time queue size changes.
• Denominator for drop probability calculation—The bigger the denominator is, the smaller the
calculated drop probability is.
Configuring WRED on an interface
Configuration procedure
Before configuring the qos wred enable command, you must enable WFQ queuing on the interface.
To configure WRED on an interface:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter interface view.
interface interface-type interface-number
N/A
3. Enable WRED.
qos wred [ dscp | ip-precedence ]
enable
N/A
4. Set the WRED exponent
for average queue size
calculation.
qos wred weighting-constant exponent
Optional.
The default setting is 9.
5. Set the drop-related
parameters for the
precedence.
qos wred { ip-precedence ip-precedence
| dscp dscp-value } low-limit low-limit
high-limit high-limit discard-probability
discard-prob
Optional.
By default, the low-limit argument
is 10, the high-limit argument is
30, and the discard-prob
argument is 10.
6. Display the WRED
configuration on an
interface/PVC or all
interfaces/PVCs.
display qos wred interface
[ interface-type interface-number ] [ |
{ begin | exclude | include }
regular-expression ]
Available in any view.
Configuration example
Network requirements
• Enable IP precedence-based WRED on interface GigabitEthernet 1/0/1.
• Set the following parameters for packets with IP precedence 3: lower threshold 20, upper threshold
40, and drop probability denominator 15.
• Set the exponential factor for the average queue size calculation to 6.
Configuration procedure
# Enter system view.
<Sysname> system-view
# Enter interface view.
[Sysname] interface gigabitethernet 1/0/1
# Enable IP precedence-based WRED.