System information

Configuring the CMTS
6-13
Initial Downstream Configuration Tasks
Use the tasks in this section to perform the following basic downstream configuration
tasks:
• Configuring the Downstream Frequency and Modulation Rate
• Enforcing the Downstream Rate Limit
• Enabling the Downstream Port
Configuring the Downstream Frequency and Modulation Rate
Follow the steps in this section to configure the downstream center frequency and
modulation rate:
1. To enter the fixed center frequency for the downstream channel, use the cable
downstream frequency command in Interface Configuration mode, as shown
below:
MOT(config-if)#cable downstream 0 frequency {<91000000 -
857000000>}
where:
91000000 - 857000000 is the downstream frequency in Hertz.
To disable the downstream center frequency setting, use the no cable
downstream frequency command in Interface Configuration mode, as shown
below:
MOT(config-if)#no cable downstream 0 frequency {91000000 -
857000000}
2. Use the cable downstream modulation command in Interface Configuration
mode to set the downstream modulation rate, as shown below:
MOT(config-if)#cable downstream 0 modulation [64 | 256]
Note: The digital carrier frequency cannot be the same as the video carrier
frequency.