Dell BigIron RX Series, Руководство по настройке

Страница: 577 / 1458

BigIron RX Series Configuration Guide 501
53-1002253-01
Configuring multicast traffic engineering
18
Setting the averaging-fair-weight (wfq) parameter
The wfq parameter is configured as the averaging-fair-weight parameter. In this implementation,
you can set one of 13 (1 - 13) possible values. These values represent a wfg value as described in
Table 99
Calculating the values for WFQ storage mode traffic
scheduling
Weighted Fair Queueing (WFQ) scheduling is configured to be a percentage of available bandwidth
using the following formula.
w (x)
Weight of w (x) = -----------------------------------------
w0 + w1 + w2 + w3 + w4 + w5 + w6 + w7
Where.
w (x) = The value of the queue that you want to determine the weight for. It can be the value of any
weight (0 - 7).
w0 - w7 = the assigned values of the eight weights.
Weight of w (x) = the calculated weight as a percentage of the port's total bandwidth.
For example if you assign the following values to weight 0 to 7.
BigIron RX(config-if-e10000-4/1)#qos rcv-scheduler wfq 1 5 1 5 1 5 1 5
Weight 0 = 1, Weight 1 = 5, Weight 2 = 1, Weight 3 = 5, Weight 4 = 1, Weight 5 = 5, Weight 6 = 1,
and Weight 7 = 5
To determine the weight of w3.
5
Weight of w3 = -----------------------------------------
1 + 5 + 1 + 5 +1 + 5 + 1 + 5
The weight of w3 is 20.8%. Consequently, w3 (Port 2 High Priority) will get 20.83% of the group
port's total bandwidth if equal amounts of traffic are received from all eight weights.
The values of the remaining weights are calculated to be the following: w0 = 4.17%, w1 = 20.83%,
w2 = 4.17%, w4 = 4.17%, w5 = 20.83%, w6 = 4.17%, and w7 = 20.83%
Egress port shaping
The 16x10GE module is designed to provide port fairness, but the cost is a smaller number of
usable queues per input port (on egress). Traffic received on a network port will be assigned to one
of 2 egress queues with a specific drop precedence value.