# Examples: Configuring CoS on Aggregated Interfaces

This example illustrates how CoS scheduler parameters are configured and applied to aggregated interfaces.

**Applying Scaling Formula to Absolute Rates**

Configure queues as follows when the total speed of member link interfaces is 100 Mbps (the available bandwidth is 100 Mbps):

[edit class-of-service] schedulers { be { transmit-rate 10m; } af { transmit-rate 20m; } ef { transmit-rate 80m; } nc { transmit-rate 30m; } }

The total configured transmit rates of the aggregated interface
is `10m`

+ `20m`

+ `80m`

+ `30m`

= 140 Mbps, meaning the transmit rate is overconfigured by
40 percent. Therefore, the software scales down the configuration
to match the 100 Mbps of available bandwidth, as follows:

be = (10/140) * 100 = 7 percent of 100 Mbps = 7 Mbps af = (20/140) * 100 = 14 percent of 100 Mbps = 14 Mbps ef = (80/140) * 100 = 57 percent of 100 Mbps = 57 Mbps nc = (30/140) * 100 = 21 percent of 100 Mbps = 21 Mbps

**Applying Scaling Formula to Mixture of Percent and Absolute
Rates**

Configure the following mixture of percent and absolute rates:

[edit class-of-service] schedulers { be { transmit-rate 20 percent; } af { transmit-rate 40 percent; } ef { transmit-rate 150m; } nc { transmit-rate 10 percent; } }

Assuming 300 Mbps of available bandwidth, the configured percentages correlate with the following absolute rates:

schedulers { be { transmit-rate 60m; } af { transmit-rate 120m; } ef { transmit-rate 150m; } nc { transmit-rate 30m; } }

The software scales the bandwidth allocation as follows:

be = (60/360) * 100 = 17 percent of 300 Mbps = 51 Mbps af = (120/360) * 100 = 33 percent of 300 Mbps = 99 Mbps ef = (150/360) * 100 = 42 percent of 300 Mbps = 126 Mbps nc = (30/360) * 100 = 8 percent of 300 Mbps = 24 Mbps

**Configuring an Aggregated Ethernet Interface**

Configure an aggregated Ethernet interface with the following scheduler map:

[edit class-of-service] scheduler-maps { aggregated-sched { forwarding-class be scheduler be; forwarding-class af scheduler af; forwarding-class ef scheduler ef; forwarding-class nc scheduler nc; } } schedulers { be { transmit-rate percent 10; buffer-size percent 25; } af { transmit-rate percent 20; buffer-size percent 25; } ef { transmit-rate 80m; buffer-size percent 25; } nc { transmit-rate percent 30; buffer-size percent 25; } }

In this case, the transmission rate for the member link scheduler map is as follows:

`be`

—7 percent`af`

—14 percent`ef`

—57 percent`nc`

—21 percent

If you add a Fast Ethernet interface to the aggregate, the aggregate bandwidth is 200 Mbps, and the transmission rate for the member link scheduler map is as follows:

`be`

—10 percent`af`

—20 percent`ef`

—40 percent`nc`

—30 percent