Cisco Headend System Release 2.5 사용자 가이드
1-4
DHCT Status Reporting Utility
78-738186-01 Rev B
What Causes DHCTs to Become Non-Responders?
Introduction
This section lists some of the conditions that may contribute to DHCTs becoming
non-responders.
Conditions in the Subscriber’s Home
Subscribers themselves may be responsible for causing some DHCTs to become non-
responders. The following list contains a few examples of conditions that might exist
in a subscriber’s home that could cause the subscriber’s DHCT to be a non-responder:
•
•
Subscriber installs a one-way power amplifier—A one-way power amplifier blocks
return transmissions.
•
Subscriber installs a signal splitter—A signal splitter may reduce the strength of
return transmissions or, in some cases, completely block the return transmission.
•
Subscriber connects the DHCT to a light switch or a power strip—The DHCT
receives no power when the light switch or power strip is turned off.
DHCT Memory and Hardware Issues
The following list contains some examples of DHCT memory and hardware issues
that might cause a DHCT to become a non-responder:
•
•
Outdated DHCT operating system—Early versions of the operating system used
in DHCTs had memory issues that might cause a DHCT to malfunction.
•
Miscellaneous internal failures—Internal components of the DHCT may fail and
cause the DHCT to become a non-responder.
Return-Path Network Conditions
The following list contains some return-path network conditions that might cause a
DHCT to become a non-responder:
•
•
Laser clipping—Lasers that assist in return path communications may be
calibrated incorrectly, resulting in a distortion of signal.
•
Over-utilization of existing design—Installation technicians may have installed
more signal splitters on the network than designed.
•
Signal interference—The quality of the return transmission may be poor due to
ingress or intermodulation.
Note: Ingress refers to noise from an external source; intermodulation refers to
Note: Ingress refers to noise from an external source; intermodulation refers to
noise generated from within the network.