Cambium Networks PTP 820 Series User Manual page 896

Chapter 19: Quality of Service (QoS) (CLI)
Configuring WRED (CLI)
This section includes:
•
WRED Overview (CLI)
•
Configuring WRED Profiles (CLI)
•
Assigning a WRED Profile to a Queue (CLI)
WRED Overview (CLI)
Weighted Random Early Detection (WRED) enables differentiation between higher and lower priority traffic based
on CoS. You can define up to 30 WRED profiles. Each profile contains a green traffic curve and a yellow traffic
curve. These curves describe the probability of randomly dropping frames as a function of queue occupancy.
The system also includes two pre-defined read-only profiles. These profiles are assigned WRED profile IDs 31 and
32:
•
Profile number 31 defines a tail-drop curve and is configured with the following values:
o
100% Yellow traffic drop after 64kbytes occupancy.
o
100% Green traffic drop after 128kbytes occupancy.
o
Yellow maximum drop is 100%
o
Green maximum drop is 100%
•
Profile number 32 defines a profile in which all will be dropped. It is for internal use and should not be applied
to traffic.
A WRED profile can be assigned to each queue. The WRED profile assigned to the queue determines whether or
not to drop incoming frames according to the occupancy of the queue. As the queue occupancy grows, the
probability of dropping each incoming frame increases as well. As a consequence, statistically more TCP flows will
be restrained before traffic congestion occurs.
Configuring WRED Profiles (CLI)
To configure a WRED profile, enter the following command in root view:
root> ethernet qos wred-profile-tbl add profile-id <profile-id> green-
min-threshold <green-min-threshold> green-max-threshold <green-max-
threshold> green-max-drop <green-max-drop> yellow-min-threshold <yellow-
min-threshold> yellow-max-threshold <yellow-max-threshold> yellow-max-
drop <yellow-max-drop>
To edit an existing WRED profile, enter the following command in root view:
root> ethernet qos wred-profile-tbl edit profile-id <profile-id> green-
min-threshold <green-min-threshold> green-max-threshold <green-max-
threshold> green-max-drop <green-max-drop> yellow-min-threshold <yellow-
min-threshold> yellow-max-threshold <yellow-max-threshold> yellow-max-
drop <yellow-max-drop>
To display a WRED profile, enter the following command in root view:
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Configuring WRED (CLI)