Users Guide

Conguring Policy-Based Rate Shaping
To congure policy-based rate shaping, use the following command.
• Congure rate shape egress trac.
QOS-POLICY-OUT mode
rate-shape
Allocating Bandwidth to Queue
The switch schedules packets for egress based on Decit Round Robin (DRR). This strategy oers 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 69. 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 aects 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
Allocating Memory in the Dynamic Buer Pool for a Specic Trac
You can restrict any class of trac from utilizing the available bandwidth to a dened limit. Restricting a trac to a certain level ensures
that when the particular class of trac uses more than certain bandwidth during congestion, the system drops the trac. This ensures the
latency of the trac is not aected.
To restrict a trac from utilizing the available bandwidth to a dened limit, allocate the memory for that trac from the dynamic buer
pool. To dene the memory, follow these steps:
1 Create a QOS policy output.
qos-policy-output qos-output-policy-name
2 Dene the bandwidth percentage.
bandwidth-percentage percentage
3 Congure the rate shape.
rate-shape value committed value
Quality of Service (QoS)
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