D-Link DES-3550 Product Manual - Page 100

Scheduling, No Limit, Effective Rx rate, QoS Output Scheduling window, Parameter

Page 100 highlights

xStack® DES-3500 Series Layer 2 Stackable Fast Ethernet Managed Switch User Manual No Limit Rate Effective Rx rate Effective Tx rate receiving and transmitting packets. This drop-down menu allows you to specify that the selected port will have no bandwidth limit. Enabled disables the limit. This field allows you to enter the data rate, in Mbit/s, that will be the limit for the selected port. Specifies the limitation of the received data rate. Specifies the limitation of the transmitted data rate. Click Apply to set the bandwidth control for the selected ports. Results of configured Bandwidth Settings will be displayed in the Port Bandwidth Table. 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. Click, Configuration > QoS > Scheduling to view the window shown below. Figure 6- 53. QoS Output Scheduling window You may assign the following values to the QoS classes to set the scheduling. Parameter Description Max. Packets (0-255) Max. Latency (0-255) 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. 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. 85

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xStack
®
DES-3500 Series Layer 2 Stackable Fast Ethernet Managed Switch User Manual
85
receiving and transmitting packets.
No Limit
This drop-down menu allows you to specify that the selected port will have no bandwidth limit.
Enabled
disables the limit.
Rate
This field allows you to enter the data rate, in Mbit/s, that will be the limit for the selected port.
Effective Rx rate
Specifies the limitation of the received data rate.
Effective Tx rate
Specifies the limitation of the transmitted data rate.
Click
Apply
to set the bandwidth control for the selected ports. Results of configured Bandwidth Settings will be displayed in the
Port Bandwidth Table
.
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. Click,
Configuration
>
QoS
>
Scheduling
to view the window shown below.
Figure 6- 53. QoS Output Scheduling window
You may assign the following values to the QoS classes to set the scheduling.
Parameter
Description
Max. Packets (0-255)
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.
Max. Latency (0-255)
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.
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.