Technical information

ADC Telecommunications, Inc.
506 C
HAPTER 18: CONFIGURING AND MONITORING CABLE MODEM TERMINATION SYSTEMS
unacceptable and a change in the operating parameters for the channel is
made based on the policies that are specified.
When the error threshold is reached over the configurable time, the
upstream frequency and burst profile are changed to those specified in the
modulation profile. This allows you to have considerable control and
flexibility. For example, when the upstream spectrum for a channel degrades,
the initial policy specified may be to keep the tuned center frequency the
same and increase FEC, or change from 16 QAM to QPSK in an attempt to
improve the use of the spectrum. If the change in operating parameters
based on the first policy fails to meet the configured error threshold, then
the next policy may be to change to another center frequency in an attempt
to find another channel with acceptable quality. Each of these policies is
attempted in a round-robin fashion to maintain upstream quality.
Frequency Hopping also allows you to monitor the condition of your plant.
Within the Spectrum Group window you may monitor these statistics:
■ Error Rate — The percentage of errors.
■ Error Count — The number of frames with errors.
■ Total Packets — The total number of frames received for each policy.
Before You Begin
Before you configure Frequency Hopping, follow this procedure:
1. Navigate to Network Browser > GroupName > ChassisName > Cuda
Chassis Manager > Configuration > CMTS > Interfaces.
2. In the Interfaces tab, select the interface that you wish to configure.
3. Click the Upstreams tab. The Upstreams configuration window appears.
4. Click the Spectrum Group tab. The Spectrum Group window appears.