EtherHaul Operation, Administration and Maintenance Manual
Page 80
Weighted Fair Queuing (WFQ) can be used to provide different rates to different flows
while maintaining fairness in order to avoid starvation. WFQ is a data packet scheduling
technique that provides different scheduling priorities to statistically multiplexed data
flows.
If the link data rate is R, weights of N data flows are W1,W2,…,Wn, the i’th data flow will
achieve an average data rate of:
R*Wi / (W1 + W2 + … + Wn)
WFQ explicitly considers data queue, and by regulating the weights dynamically, you can
utilize WFQ to control the QoS.
WFQ can only be configured for ETH0 queues 1 through 5. The highest queues, 6 and 7,
are Strict Priority queues, and the lowest queue, 0, is on a best effort basis.
9.4.3
Scheduling Mode: Priority-Shaper
Figure 9-8 Advanced Config Page: Quality of Service
– Scheduler Mode Priority-Shaper
Shaper is used to control traffic flows in order to optimize or guarantee performance
and improve latency by limiting the maximum bandwidth of certain flows to maintain
fairness and to assure SLA.
Shaper can only be configured for ETH0 queues 1 through 5. The highest queues, 6 and
7, are Strict Priority queues, and the lowest queue, 0, is on a best effort basis.
You can set the Committed Information Rate (CIR) to a value between 1-1000 Mbps (the
total of all CIR cannot exceed 1000 Mbps). The CIR value limits the maximum rate of the
particular queue.
