R2511-HP MSR Router Series ACL and QoS Configuration Guide(V5)

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• Denominator for drop probability calculation—The bigger the denominator is, the smaller the
calculated drop probability is.
Configuring WRED on an interface
Configuration procedure
CAUTION:
To configure the qos wred enable command on an interface, make sure that WFQ queuing has been
applied 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 or
PVC view.
• Enter interface view:
interface interface-type
interface-number
• Enter PVC view:
a. interface atm interface-number
b. pvc vpi/vci
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.
Configuration example
Network requirements
• Enable IP precedence-based WRED on interface Ethernet 1/1.
• 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 ethernet 1/1
# Enable IP precedence-based WRED.
[Sysname-Ethernet1/1] qos wred ip-precedence enable