Administrator Guide

When you assign a percentage to one queue, note that this change also affects the amount of bandwidth that is allocated to other
queues. Therefore, whenever you are allocating bandwidth to one queue, Dell EMC Networking recommends evaluating your bandwidth
requirements for all other queues as well.
• Assign each queue a bandwidth percentage ranging from 1 to 100%, in increments of 1%.
bandwidth-percentage
Allocating Memory in the Dynamic Buffer Pool for a Specific Traffic
You can restrict any class of traffic from utilizing the available bandwidth to a defined limit. Restricting a traffic to a certain level ensures
that when the particular class of traffic uses more than certain bandwidth during congestion, the system drops the traffic. This ensures
the latency of the traffic is not affected.
To restrict a traffic from utilizing the available bandwidth to a defined limit, allocate the memory for that traffic from the dynamic buffer
pool. To define the memory, follow these steps:
1. Create a QOS policy output.
qos-policy-output qos-output-policy-name
2. Define the bandwidth percentage.
bandwidth-percentage percentage
3. Configure the rate shape.
rate-shape value committed value
4. Define the memory from the dynamic buffer pool for a class of traffic.
dynamic-buffer-limit buffer-limit
The range is from 0 to 12288.
Specifying WRED Drop Precedence
You can configure the WRED drop precedence in an output QoS policy.
• Specify a WRED profile to yellow and/or green traffic.
QOS-POLICY-OUT mode
wred
For more information, refer to Applying a WRED Profile to Traffic.
DSCP Color Maps
This section describes how to configure color maps and how to display the color map and color map configuration.
This sections consists of the following topics:
• Creating a DSCP Color Map
• Displaying Color Maps
• Display Color Map Configuration
Creating a DSCP Color Map
You can create a DSCP color map to outline the differentiated services codepoint (DSCP) mappings to the appropriate color mapping
(green, yellow, red) for the input traffic. The system uses this information to classify input traffic on an interface based on the DSCP value
of each packet and assigns it an initial drop precedence of green, yellow, or red
The default setting for each DSCP value (0-63) is green (low drop precedence). The DSCP color map allows you to set the number of
specific DSCP values to yellow or red. Traffic marked as yellow delivers traffic to the egress interface, which will either transmit or drop
the packet based on configured queuing behavior. Traffic marked as red (high drop precedence) is dropped.
Important Points to Remember
• All DSCP values that are not specified as yellow or red are colored green (low drop precedence).
• A DSCP value cannot be in both the yellow and red lists. Setting the red or yellow list with any DSCP value that is already in the other
list results in an error and no update to that DSCP list is made.
• Each color map can only have one list of DSCP values for each color; any DSCP values previously listed for that color that are not in
the new DSCP list are colored green.
• If you configured a DSCP color map on an interface that does not exist or you delete a DSCP color map that is configured on an
interface, that interface uses an all green color policy.
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Quality of Service (QoS)