This example presumes that you have configured the rules according to
the commands illustrated at the start of this section. All the voice flows in
bucket 1. All the CIR data flows are categorized in bucket 8.
This example illustrates a sample configuration for SFAC with
downstream traffic. In this example, if voice traffic exceeds 30% bandwidth
consumption, additional voice flows are denied.
- 30% downstream throughput
is reserved exclusively for voice traffic.
- Minor and major alarms
for voice traffic to be generated at 15% and 25% respectively.
The following Cisco IOS command implements this configuration:
Router(config)# cable admission-control ds-bandwidth bucket-no 1 minor 15 major 25 exclusive 30
In this example, the voice flows are rejected when the bandwidth
usage of the flows exceeds 30%.
In addition, you can allow for some flexibility by allowing flows to
exceed their exclusive share, and to consume up to 50% of the total downstream
throughput (30% + 20%). The following command accomplishes this:
Router(config)# cable admission control downstream bucket-no 1 minor 15 major 25 exclusive 30 non-exclusive 20
With this previous command, the bucket 1 flows are rejected when the
voice usage exceeds 50% (30% + 20%).
Similarly you can configure data thresholds as follows:
Router(config)# cable admission control bucket-no 8 minor 15 major 25 exclusive 50 non-exclusive 10
With the configuration commands as above, the following multi-stage
scenario illustrates how the lending and borrowing of throughput is achieved in
the presence of multiple traffic classes.