Traffic Policing and Shaping
Configuring QoS
page 25-22
OmniSwitch AOS Release 7 Network Configuration Guide
June 2013
Configuring the WRED Profile
Configuring the WRED profile consists of enabling or disabling the administrative status of the profile for
a specific QSet instance. By default, WRP 1 is disabled for each QSet instance. To enable the profile for
the instance, use the
command. For example:
-> qos qsi port 1/10 wred admin-state enable
-> qos qsi port 1/20-22 wred admin-state enable
-> qos qsi linkagg 5 wred admin-state enable
Consider the following when configuring the WRED profile status:
•
WRP 1 is the only profile supported. Configuring additional profiles is not supported at this time
•
The default WRP 1 profile parameters are not configurable and the profile cannot be deleted from the
switch configuration.
•
The WRED profile status is applied to all the unicast queues associated with the QSet instance for the
port. Enabling or disabling WRED at the queue level is not supported.
•
The queue threshold values applied are similar to configuring and applying bandwidth shaping rates to
limit bandwidth.
•
The maximum queue threshold value applied determines the delay a packet may experience while wait-
ing for the queue to clear out other packets that arrived first.
To verify the WRED profile configuration, use the
command. For example:
-> show qos wrp
WRP 1 (wrp-1)
#Ports: 368, MTU: 1540
Red
Min-Th: 10, Max-Th: 50, Max-Pb: 36, Gain: 9
Yellow
Min-Th: 50, Max-Th: 90, Max-Pb: 30, Gain: 9
Green
Min-Th: 90, Max-Th: 100, Max-Pb: 24, Gain: 9
See the
OmniSwitch CLI Reference Guide
for more information about the
qos qsi wred
and
show qos wrp
commands.
Traffic Policing and Shaping
Traffic policing and shaping mechanisms are used to limit the rate of traffic. The main difference between
the two is how they handle traffic that violates the specified rate. Policing either drops or remarks traffic
that exceeds a configured maximum rate. Shaping delays the transmission of packets that exceed config-
ured rates by placing the packets in a queue and scheduling them to be sent at a later time.
The OmniSwitch 10K provides the following techniques for policing and shaping traffic flows.
Policing
•
QoS Tri-Color Marking (TCM) policy
. A TCM policy consists of a policy action that specifies
packet rates and burst sizes. The policy condition defines the type of traffic for TCM to meter and then
color mark (green, yellow, or red) based on conformance with the rate limits defined in the policy
action. See
“Tri-Color Marking” on page 25-23
.