Scheduling; 802.1P Default Priority - D-Link DES-3526 Manual

Scheduling

Changing the output scheduling used for the hardware queues in the Switch can customize QoS. As
with any changes to QoS implementation, careful consideration should be given to how network
traffic in lower priority queues is affected. Changes in scheduling may result in unacceptable levels of
packet loss or significant transmission delay. If you choose to customize this setting, it is important to
monitor network performance, especially during peak demand, as bottlenecks can quickly develop if
the QoS settings are not suitable. In the Configuration folder open the QoS folder and click QoS
Output Scheduling, to view the window shown below.
You may assign the following values to the QoS classes to set the scheduling.
Parameter
Max. Packets (0-255)
Max. Latency (0-255)
Click Apply to implement changes made.
NOTE: The settings you assign to the queues, numbers 0-7, represent
the IEEE 802.1p priority tag number. Do not confuse these settings
with port numbers.

802.1p Default Priority

The Switch allows the assignment of a default 802.1p priority to each port on the Switch. In the
Configuration folder open the QoS folder and click 802.1p Default Priority, to view the window
shown below.
DES-3526 / DES-3526DC Fast Ethernet Layer 2 Switch
Figure 6- 44. QoS Output Scheduling window
Description
Specifies the maximum number of packets the above specified hardware priority
queue would be allowed to transmit before allowing the next lowest priority queue
to transmit its packets. A value between 0 and 255 can be specified.
Specifies the maximum amount of time the above specified hardware priority
queue will be allowed to transmit packets before allowing the next lowest
hardware priority queue to begin transmitting its packets. A value between 0 and
255 can be specified - with this value multiplied by 16 ms to arrive at the total
allowed time for the queue to transmit packets. For example, a value of 3
specifies 3 X 16 = 48 ms. The queue will continue transmitting the last packet until
it is finished when the max latency timer expires.
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