Queue Scheduling - Linksys LGS308 User Manual

2. Enter the parameters.
• Interface—Select the port or LAG.
Default CoS—Select the default CoS (Class-of-Service) value to be assigned for
•
incoming packets (that do not have a VLAN tag).
3. Click Apply. The interface default CoS value is saved to Running Configuration file.

Queue Scheduling

The device supports 4 queues for each interface. Queue number four is the highest priority queue.
Queue number one is the lowest priority queue.
There are two ways of determining how traffic in queues is handled:
• Strict Priority—Egress traffic from the highest-priority queue is transmitted first. Traffic
from the lower queues is processed only after the highest queue has been transmitted,
thus providing the highest level of priority of traffic to the highest numbered queue.
Weighted Round Robin (WRR)—In WRR mode, the number of packets sent from the queue
•
is proportional to the weight of the queue (the higher the weight the more frames are sent).
For example, if there are a maximum of four queues possible and all four queues are WRR
and the default weights are used, queue 1 receives 1/15 of the bandwidth (assuming all
queues are saturated and there is congestion), queue 2 receives 2/15, queue 3 receives
4/15 and queue 4 receives 8 /15 of the bandwidth. The type of WRR algorithm used in the
device is not the standard Deficit WRR (DWRR), but rather Shaped Deficit WRR (SDWRR).
The queuing modes can be selected in the Queue Scheduling page. When the queuing mode is by
strict priority, the priority sets the order in which queues are serviced, starting with Queue 4 (the
highest priority queue) and going to the next lower queue when each queue is completed.
When the queuing mode is Weighted Round Robin, queues are serviced until their quota has been
used up and then another queue is serviced.
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