Dell PowerConnect B-RX - Page 571

BigIron RX Series Configuration Guide 495
53-1002253-01
Scheduling traffic for forwarding
18
Configuring strict priority-based traffic scheduling
To configure strict priority-based scheduling use a command such as the following.
BigIron RX(config)# interface ethernet 1/1
BigIron RX(config-if-e1000-1/1)# qos scheduler strict
Syntax: qos scheduler strict
Configuring enhanced strict priority-based traffic scheduling
To configure enhanced strict priority-based scheduling use a command such as the following.
BigIron RX(config)# interface ethernet 1/1
BigIron RX(config-if-e1000-1/1)# qos scheduler enhanced-strict 100 100 100
Syntax: qos scheduler enhanced-strict <Queue0-rate> <Queue1-rate> <Queue2-rate>
The <Queue0-rate> variable defines the minimum bandwidth allocated to lower-priority traffic rate
in Kbps for forwarding queue 0.
The <Queue1-rate> variable defines the minimum bandwidth allocated to lower-priority traffic rate
in Kbps for forwarding queue 1.
The <Queue2-rate> variable defines the minimum bandwidth allocated to lower-priority traffic rate
in Kbps for forwarding queue 2.
Calculating the values for WFQ source and destination-based traffic scheduling
Weighted Fair Queueing (WFQ) scheduling is configured to be a percentage of available bandwidth
using the following formula.
Where:
q (x) = The value of the queue that you want to determine the weight for. It can be the value of any
queue (0 - 3).
q0 - q3 = the assigned values of the four queues.
Weight of q (x) = the calculated weight as a percentage of the port’s total bandwidth.
For example if you assign the following values to queues 0 to 3.
• Queue 0 = 5, Queue 1 = 10, Queue 2 = 15, and Queue 3 = 20
NOTE
Where rates are configured, the minimum rate supported is 248 Kbps for 1 Gbps ports and 2480
Kbps for 10 Gbps ports.
To determine the weight of q3.
The weight of q3 is 40%. Consequently, q3 will get 40% of the port’s total bandwidth.
q (x)
Weight of q (x) = -----------------------------------------
q0 + q1 + q2 +q3
20
Weight of q3 = -----------------------------------------
5 + 10 + 15 + 20