Cisco 7246 - uBR Router Configuring page 12

Configure the Upstream Cable Interface
Configure the Upstream Cable Interface
The next step is to configure the upstream cable interface. In this case, upstream refers to the data
flow from a cable modem to the Cisco MC11 modem card in a Cisco uBR7246. The user's cable
modem sends an RF signal back to the MC11 cable modem card, which translates the RF signal back
to data format. Upstream cable interface commands configure the frequency and input power level
of the upstream signal, in addition to error detection and correction of the upstream signal.
The configuration of the upstream cable interface depends on each cable operator's physical plant.
Perform the following tasks to configure the upstream cable interface:
•
Set the Upstream Frequency
•
Set the Upstream Input Power Level
•
Activate Upstream Forward Error Correction
•
Activate the Upstream Scrambler
•
Activate the Upstream Ports
Set the Upstream Frequency
You need to set the upstream frequency of your RF output to comply with the expected input
frequency of your Cisco MC11 cable modem. You do this by entering a fixed frequency of the
upstream RF carrier for an upstream port. The valid range for a fixed upstream frequency is
5,000,000 Hz to 42,000,000 Hz.
Note
for any other upstream applications running in the cable plant.
Note
and configure a spectrum group. See the section "Create Spectrum Groups" later in this document.
To set the upstream frequency, use the following command in cable interface configuration mode:
Command
cable upstream port frequency up-freq-hz
VC-144 Voice, Video, and Home Applications Configuration Guide
Make sure that the upstream frequency selected does not interfere with the frequencies used
The cable interface will not operate until you either set a fixed upstream frequency or create
Purpose
Enter the fixed center frequency for your upstream RF
carrier in Hz.