D-Link DES-1228/ME User Manual - 802.1P User Priority
DES-1228/ME Layer 2 Fast Ethernet Managed Switch
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802.1p User Priority
When using 802.1p priority mechanism, the packet is examined for the presence of a valid 802.1p priority tag. If the tag is present,
the packet is assigned to a programmable egress queue based on the value of the tagged priority. The tagged priority can be
designated to any of the available queues.
The Switch allows the assignment of a class of service to each of the 802.1p priorities. To view this window click CoS > 802.1p
User Priority.
Figure 8- 4. 802.1p User Priority window
Once you have assigned a priority to the port groups on the Switch, you can then assign this Class to each of the four levels of
802.1p priorities. Click Apply to set your changes.
CoS Scheduling Mechanism
This drop-down menu allows you to select between a Weight Fair and a Strict mechanism for emptying the priority classes. To
view this window click CoS > CoS Scheduling Mechanism.
Figure 8- 5. CoS Scheduling Mechanism and CoS Scheduling Mechanism Table window
NOTICE: The default CoS scheduling arrangement is a strict priority schedule for the highest class
(Class-3) which means the Switch will consider the highest class of service to have strict scheduling
only, while the other queues empty in a round-robin method.