Cisco Headend System Release 2.5 User Guide
Interface of the DHCT Status Reporting Utility
4031374 Rev B
101
Section 2 - SETTOP InService 2 Way Poll Analysis
DHCT Analysis
The SETTOP InService 2 Way Poll Analysis section is referenced by the number 2.
This area of the interface of the DHCT Status Reporting Utility presents a detailed
analysis of those DHCTs listed in the database that are capable of two-way
communication. The SETTOP InService 2 Way Poll Analysis section includes the
following items:
This area of the interface of the DHCT Status Reporting Utility presents a detailed
analysis of those DHCTs listed in the database that are capable of two-way
communication. The SETTOP InService 2 Way Poll Analysis section includes the
following items:
The number of DHCTs with two-way capability that have an IP address (2Way
w/IP Addrs) and the number of DHCTs with two-way capability that do not have
an IP address (2Way w/oIP Addrs).
w/IP Addrs) and the number of DHCTs with two-way capability that do not have
an IP address (2Way w/oIP Addrs).
For DHCTs with an IP address, the totals and percentages that transmit at the
following transmit levels:
following transmit levels:
-
Between and including 25 and 55 dBmV (decibels referenced to 1 millivolt)
(RDC Btwn 25-55 dBmV)-DHCTs communicate with the headend between
and including 25 and 55 dBmV.
(RDC Btwn 25-55 dBmV)-DHCTs communicate with the headend between
and including 25 and 55 dBmV.
-
No response (Not Resp. to Poll)-The DNCS is unable to get a response after
polling these DHCTs.
polling these DHCTs.
-
Below 25 dBmV (RDC Below 25 dBmV)-DHCTs respond to the poll, but
respond at a transmit level below the optimum level specified by our
engineers.
respond at a transmit level below the optimum level specified by our
engineers.
-
Higher than 55 dBmV (RDC Above 55 dBmV)-DHCTs respond to the poll,
but respond at a transmit level higher than the optimum level specified by
our engineers.
but respond at a transmit level higher than the optimum level specified by
our engineers.
High or Low Transmit Levels
Even though DHCTs can transmit successfully at levels higher than 55 dBmV or
lower than 25 dBmV, the fact that these DHCTs exist on a system may indicate a
serious configuration problem. Occasionally, the entire population of DHCTs
assigned to a specific QPSK modulator or demodulator may transmit at levels that
are too high or too low. The system can support two-way communications with a
portion of these DHCTs; other DHCTs assigned to this modulator or demodulator
may transmit at levels that are too high or too low to even be recognized.
lower than 25 dBmV, the fact that these DHCTs exist on a system may indicate a
serious configuration problem. Occasionally, the entire population of DHCTs
assigned to a specific QPSK modulator or demodulator may transmit at levels that
are too high or too low. The system can support two-way communications with a
portion of these DHCTs; other DHCTs assigned to this modulator or demodulator
may transmit at levels that are too high or too low to even be recognized.
Consider this rule of thumb: if 3 percent or more of successfully responding DHCTs
respond at levels higher than 55 dBmV or lower than 25 dBmV, you can assume that
there are other DHCTs responding with signals too high or too low to be recognized.
respond at levels higher than 55 dBmV or lower than 25 dBmV, you can assume that
there are other DHCTs responding with signals too high or too low to be recognized.
Note: You can see an illustration of this concept in the graph under Examples of