Dell S4048T, Configuration Manual

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Configuring Policy-Based Rate Shaping
To configure policy-based rate shaping, use the following command.
• Configure rate shape egress traffic.
QOS-POLICY-OUT mode
rate-shape
Allocating Bandwidth to Queue
The switch schedules packets for egress based on Deficit Round Robin (DRR). This strategy offers a
guaranteed data rate.
Allocate bandwidth to queues only in terms of percentage in 4-queue and 8-queue systems. The following
table shows the default bandwidth percentage for each queue.
The following table lists the default bandwidth weights for each queue, and their equivalent percentage which
is derived by dividing the bandwidth weight by the sum of all queue weights.
Table 71. Default Bandwidth Weights
Queue Default Bandwidth Percentage for
4–Queue System
Default Bandwidth Percentage for
8–Queue System
0 6.67% 1%
1 13.33% 2%
2 26.67% 3%
3 53.33% 4%
4 - 5%
5 - 10%
6 - 25%
7 - 50%
NOTE: The system supports 8 data queues.
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
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
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 .
Quality of Service (QoS) 844