Scheduling; Qos Queuing Methods - Dell PowerConnect B-FCXs Configuration Manual

Hardware Queue
3
2
1
0
The example configuration described below is for a default, non-jumbo mode. The hardware
queues for WRR mode is calculated as follows.
Front end queue 3= 75%+7% = 82%
Front end queue 2 = 3%+3% = 6%
Front end queue 1 = 3%+3% = 6%
Front end queue 0 = 3%+3% = 6%
The hardware queues for Hybrid WRR and SP mode is calculated as follows.
Front end queue 3 is strict priority
Front end queue 2 = 25%+15% = 40%
Front end queue 1 = 15%+15% = 30%
Front end queue 0 = 15%+15% = 30%

Scheduling

Scheduling is the process of mapping a packet to an internal forwarding queue based on its QoS
information, and servicing the queues according to a mechanism.

QoS queuing methods

The following QoS queuing methods are supported in all IronWare releases for the PowerConnect
devices:
•
PowerConnect B-Series FCX Configuration Guide
53-1002266-01
Weighted Round
Robin (WRR)
mode
Weight 82%
Weight 6%
Weight 6%
Weight 6%
Weighted round robin (WRR) – WRR ensures that all queues are serviced during each cycle. A
WRR algorithm is used to rotate service among the eight queues on the PowerConnect
devices. The rotation is based on the weights you assign to each queue. This method rotates
service among the queues, forwarding a specific number of packets in one queue before
moving on to the next one.
NOTE
In stacking mode, the qosp7 queue is reserved as strict priority (SP) under weighted queuing.
Attempts to change the qosp7 setting will be ignored.
WRR is the default queuing method and uses a default set of queue weights.
The number of packets serviced during each visit to a queue depends on the percentages you
configure for the queues. The software automatically converts the percentages you specify into
weights for the queues.
Hybrid WRR and Strict Priority (SP)
SP mode
Strict Priority Strict Priority
Weight 40% Strict Priority
Weight 30% Strict Priority
Weight 30% Strict Priority
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Scheduling
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