(a) Check the level of the multichannel VFCT
tones at the voice frequency patch panel and instruct
(3) Telephone numbers.
(4) Date, time and trouble number.
(4) When the trouble has been isolated and cor-
(5) Station reported to.
rected by coordinating the maintenance necessary to
(6) Names or initials of
restore operations, notify the distant Technical Con-
d. Inquiries concerning
status of reported
troller of the nature of the problem and restore the
user circuits to normal.
carrier will provide information as
concerning the status of the circuit
(5) If the malfunction cannot be corrected in a
reasonable length of time (Le., 10 minutes), the Tech-
The commercial carrier may include probably location
nical Controller should notify the appropriate DOCC
of trouble switch to an alt-route, but they are not
and, if required, request rerouting instructions for pri-
required to furnish more detailed information. Only
ority channels pending the completion of repairs.
information concerning restoral of circuit or in-effect
between the commercial
(6) Complete station records, trouble reports, log
entries, etc., in accordance with established proce-
4-35. Examples of Voice Channel Fault
Initial testing will be conducted to determine whether
There are a number of acceptable methods of isolating
the reported trouble is in the local terminal portion,
a faulty link in a communications channel. Two meth-
distant terminal portion, or in the leased portion of the
ods are explained in this paragraph . The first method
(discussed in a and b below) requires the isolation pro-
circuit. So that such testing can be accomplished, it is
cedure to begin at the point of fault recognition. Each
essential that all parties concerned definitely under-
site clears itself of any responsibility for fault by
stand the extent of their responsibility.
a. Military terminals are responsible for establish-
ing proper circuitry, correct operation of equipment
sponsible TCF to isolate the fault over the whole com-
and circuitry from and to the terminals where the
munications chain by having the signal from the local
commercial carriers responsibility begins at the inter-
TCF looped back and tested at various points in succes-
sion along the chain
b. The commercial carrier is responsible for estab-
a. Noise Burst on Multiplexed Through Circuit. The
lishing and maintaining the type of service requested
procedure followed is outlined in flow-chart fashion in
by the military between the designated terminals. This
tant Technical Controller is notified
figure 4-7. Th
includes troubleshooting and restoration of service up
that noise bursts are being received by a subscriber.
to the interface points. The following action will be
The complaint has been verified at the distant end,
and that station has been cleared of causing the
(1) Call the appropriate commercial circuit control
trouble. The noise bursts are incoming to the distant
office for trouble reporting.
Technical Control Facility, and that Technical Con-
(2) Provide an account of the trouble indicated ac-
troller requests that the local Technical Controller
cording to results obtained from tests.
clear the local station of being the cause of the noise
(3) The nature and indications of common
bursts. The local controller is responsible for simply
troubles encountered on leased or military circuits are
checking the circuit through the site to determine if
listed below. The terms listed have been chosen so that
the fault source is in the station, reporting back to the
the nature of the trouble will be understood by com-
distant station, and correcting the fault if necessary.
mercial carrier personnel throughout the world who
Following is an example of an isolation procedure for
have contact with the DCS.
this type of fault:
(a) No receive current or signal.
(1) At the equal level patch panel farthest from
(b) Cannot receive ringing current.
the complaining subscriber, connect a loudspesker to
(c) Levels too low.
the receive monitor jack of the affected circuit.
(d) Excessive noise.
(2) Listen for the noise burst complaint.
(e) Intense crosstalk.