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Cisco uBR10012 Universal Broadband Router Software Configuration Guide
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Chapter3 Configuring Cable Interface Features for the CiscouBR10012Router Configuring the Upstream Cable Interface
Configuring the Upstream Cable Interface
These configurations are required. 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 the characteristics of your cable
plant.
Perform the following tasks in this section to configure the upstream cable interface.
Note For some of these tasks, default values are adequate to configure the device.
Task Description
“Activating Upstream Admission
Control” section on page12 Provides information about the upstream admission control
feature, and provides instructions to set the upstream admission
control as a percentage of the upstream channel capacity.
“Activating Upstream Differential
Encoding” section on page13 Provides brief explanation and instructions to activate
differential encoding on the upstream, which is a digital
encoding technique whereby a binary value is denoted by a
signal change rather than a particular signal level.
“Activating Upstream Forward
Error Correction” section on
page14
Provides instructions to activate forward error correction
(FEC). The CiscouBR10000series CMTS uses FEC to attempt
to correct any upstream data that might have been corrupted.
“Activating the Upstream Ports”
section on page14 Provides instructions to activate upstream ports. Each upstream
port must be activated to enable upstream data transmission
from the CMs on the HFC network to the
CiscouBR10000series CMTS.
“Activating Upstream Power
Adjustment” section on page15 Provides instructions to enable upstream power adjustment.
This feature sets the minimum power adjustment in dB that will
allow continued ranging status.
“Activating the Upstream
Scrambler” section on page16 Provides instructions to activate the upstream scrambler on the
upstream RF carrier, which enables CMs on the HFC network
to use built-in scrambler circuitry for upstream data
transmissions.
“Activating Upstream Timing
Adjustment” section on page16 Provides instructions to activate upstream timing adjustment on
the specified interface. This feature sets the minimum timing
adjustment that allows continued ranging status.
“Setting Upstream Backoff Values”
section on page17 Provides DOCSIS-compliant instructions that define
contention resolution for CMs wanting to transmit data or
requests on the upstream channel. Contention resolution is
achieved with a truncated binary exponential backoff value.
“Setting the Upstream Channel
Width” section on page19 Provides instructions to enter the upstream channel width in
hertz (Hz). Also describes NTSC spectrum parameters and
spectrum management processes.
“Setting the Upstream Frequency”
section on page20 Provides instructions to set upstream channel frequency for the
RF output that complies with the expected input frequency of
the Cisco cable interface line card.