Installation guide

5-44
Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
OL-2238-03
Chapter 5 Troubleshooting the System
Setting Downstream Test Signals
Setting Frequency Threshold to Affect Power Adjustment
To control power adjustment methods by setting the frequency threshold, use the
cable upstream freq-adj averaging interface configuration command. To disable power adjustments,
use the no form of this command.
cable upstream n freq-adj averaging % of frequency adjustment
no cable upstream freq-adj averaging
The following example shows how to change the power adjustment method when the frequency
adjustment packet count reaches 50 percent:
Router(config-if)# cable upstream 0 freq-adj averaging 50
Setting Downstream Test Signals
This feature provides configuration commands that allow you to create downstream test signals. Both
Pseudo Random Bit Stream (PRBS) and unmodulated carrier test signals are now supported.
A PRBS test signal is a random data pattern that has been modulated to look like a real data stream. An
unmodulated test signal is a continuous sine wave that looks like a carrier wave on the downstream
transmission.
See the following required tasks to create PRBS and unmodulated carrier test signals:
• “Configuring Unmodulated Test Signals” section on page 5-45
• “Configuring PRBS Test Signals” section on page 5-45
• “Verifying Test Signal Output” section on page 5-45
Table 5-10 Cable Upstream Freq-adj Averaging Syntax Descriptions
Syntax Description
n
Specifies the upstream port number.
averaging
Specifies that a percentage of frequency adjustment packets is
required to change the adjustment method from the regular power
adjustment method to the noise power adjustment method.
% of frequency adjustment
Specifies the percentage of frequency adjustment packets required to
switch from the regular power adjustment method to the noise power
adjustment method. Valid range is from 10 to 100 percent.