Configuring Wred On An Interface; Configuration Procedure; Configuration Example - HP MSR4080 Configuration Manual

drop probability. When the average queue size exceeds the upper threshold, subsequent packets
are dropped.
Drop precedence—A parameter used for packet drop. The value 0 corresponds to green packets,
•
the value 1 corre
are dropped preferen
Exponent for average queue si
•
average queue size is to real-time queue size c
queue size is average queue size =
x 2 ), where n is the exponent.
–n
Denominator for drop probability calculation—The greater the denominator, the smaller the
•
calculated drop probability.
Conf iguring WRED on an interface
Confi guration procedure
To configure WRED on an interface:
Step
1. Enter system view.
2. Enter interface or
3. Enable WRED.
(Optional.) Set the WRED
4.
exponent for average queue
size calculation.
5. (Optional.) Set the
drop-related parameters for a
precedence value.

Configuration example

Network requirements
Configure WRED as follows:
• Enable IP precedence-based WRED on interface GigabitEthernet 2/1/0.
Set the following parameters for packets with IP precedence 3: lower threshold 20, upper threshold
•
40, and drop probability denominator 15.
sponds to yellow packets, and the value 2 corresponds to red packets. Red packets
tially.
ze calculation—The greater the exponent, the less sensitive the
( previous average queue size x (1 – 2
Command
system-view
•
Enter int
interf
interface
PVC view.
•
Enter PVC view:
a. interface atm interface-number
b. pvc vpi/vci
qos wred [ dscp | ip-precedence ]
enable
qos wred weighting-constant exponent
qos wred { ip-precedence
ip-precedence | dscp dscp-value }
low-limit low-limit high-limit high-limit
discard-probability discard-prob
hanges. The formula for calculating the average
erface view:
ace interface-type
-number
64
) ) + (current queue size
–n
Remarks
N/A
N/A
By default, tail drop is
adopted.
The default setting is 9.
By default, low-limit is 10,
high-limit is 30, and
discard-prob is 10.
Repeat this command to
configure more precedence
values.