Design Trouble Types

alarm/ALM/misc

A trouble on a circuit has been identified by alarm equipment within a LEC Central Office.

CR (Customer Report)

biPolarViolations/BPV/misc

A condition which occurs when a bit stream contains a pulse of the same polarity as the previous pulse and which is not part of the bipolar zero substitution code.

CR (Customer Report)

canNotBeSignalled/CBS/misc

The connecting circuit's signaling equipment is defective. It does not allow a circuit connect to occur.

CR (Customer Report)

canNotMeet/CMT/misc

A failure of intercom conference channel equipment's ability to establish bridged connections.

CR (Customer Report)

canNotReceiveData/CRD/
data

A modem cannot receive data when connected to a destination modem via the circuit.

CR (Customer Report)

canNotSendData/CSD/data

A modem cannot send data when connected to a destination modem via the circuit.

CR (Customer Report)

canNotSignal/CSO/misc

The premises customer's circuit does not provide signals to allow a connection to occur (for example, wink start, ground start, loop start, CCS7, SS7).

CR (Customer Report)

canNotTransmitCanNotRecv/NTR/data

A modem can neither send nor receive data when connected to a destination modem via the circuit.

CR (Customer Report)

circuitDead/CKD/ndt

No dial tone is provided when the telephone goes off-hook.

CR (Customer Report)

circuitDown/DWN/misc

There is no activity on the circuit at all. The circuit shows no sign of continuity with the service provider.

CR (Customer Report)

circuitInLoopBack/CIL/data

Unable to receive test signal from a device with loopback capabilities.

CR (Customer Report)

cutsOff/CTO/tran

Voice service user experiences an interruption during the course of service use.

CR (Customer Report)

dataFramingErrors/FRM/data

Line errors which alter the framing pattern and cause the receiver to react as if it were out of frame are present.

CR (Customer Report)

delay/DEL/misc

Usually referred to as Envelop Delay Distortion (EDD). EDD is the distortion of a signal due to differences in propagation of different frequencies which comprise the data signal. EDD is determined by measuring the delay of various frequencies, within the band of interest, with respect to a reference frequency. Absolute delay generally has little effect on data transmission.

CR (Customer Report)

dropOuts/DPO/data

The decrease in receiving signal level is equal to or greater than 12dB and lasts more than four milliseconds.

CR (Customer Report)

echo/ECO/tran

Improperly engineered echo suppressors or echo cancellers, or absence of such equipment in the Central Office facilities/equipment, cause voice echo during conversations.

CR (Customer Report)

errors/ERR/data

Errors in the data signal are detected (such as LRC-CRC errors).

CR (Customer Report)

failingCircuit/FLD/misc

Frequency tones fail to reach the distant end. Non-descriptive code.

CR (Customer Report)

gettingAllOnes/GAO/data

The bit stream indicates the line is out of service.

CR (Customer Report)

grounded/GRD/misc

A DC ground is on the wire or equipment. Often causes noise, off-hook, or garbled signal.

CR (Customer Report)

highLevels/HOT/tran

Normally, a reference to data services. Levels are smaller in reference to 0dB as shown on the engineering design.

CR (Customer Report)

historicalReports/INF/misc

Defined by local (inter-exchange carrier) practice.

CR (Customer Report)

hits/HIT/data

Sudden variation in receiving signal amplitude is equal to or greater than 3dB, and lasts more than four milliseconds.

CR (Customer Report)

hollow/HOL/tran

Improperly engineered transmission equipment power levels, load coils, echo suppressers, or echo cancellers, or the absence of such equipment for the transmission of the signal.

CR (Customer Report)

impulseNoise/IMP/misc

Large amplitude peaks that occur unpredictably in infrequent bursts against the data carrier background that produce error impairments in the data signal.

CR (Customer Report)

information/INF/misc

The circuit is not out of service. The customer is requesting attention and/or providing information outside of the normal trouble clearance process.

IN (Information)

invalidData/INV/data

Error message indicating possible bad or incorrect parameters.

CR (Customer Report)

lossOfSync/OOS/misc

In superframe (SF), once in sync, two of the last five framing bits (Ft) are in error. In extended superframe (ESF), once in sync, two of the last five framing pattern sequence bits are in error. (Intermittent)

CR (Customer Report)

lowLevels/LOW/tran

User cannot hear conversation because the voice is too low.

CR (Customer Report)

modem/STR/phys

The modem is defective or not responding. Modems can be in either the LEC Central Office or at the customer premises.

CR (Customer Report)

monitorCircuit/MON/misc

Request for a non-intrusive monitor to be placed on the circuit for a specified period to capture intermittent failures.

AT (Assist Test)

noAnswerBack/NAB/misc

No response from the far-end customer premises equipment.

CR (Customer Report)

noCarrier/NCR/data

Unable to detect the carrier signal from the far end.

CR (Customer Report)

noContinuity/NCN/misc

Inability of the transmission equipment to pass a DC continuity check to ensure the existence of an uninterrupted electrical signal for the channel or channels.

CR (Customer Report)

noDialTone/NDT/ndt

No audible dial tone is provided when the telephone goes off-hook.

CR (Customer Report)

noLoopBack/NLB/misc

Unable to receive test signal from a device with loop-back capabilities.

CR (Customer Report)

noSignal/NOS/misc

The circuit appears to be working in all directions, except for the absence of signaling.

CR (Customer Report)

offHook/OHK/phys

A telephone set or signaling equipment at the premises is causing an off-hook condition. The trouble identified might be a reorder or dead air on the line.

CR (Customer Report)

open/OPX/ndt

The circuit will not allow a DC signal to pass through it; often, an open wire or defective equipment anywhere within the circuit.

CR (Customer Report)

orderWork/ORD/misc

Customer's service has never worked, usually follows a recently closed service order to complete the provisioning process, when necessary.

CR (Customer Report)

other/OTH/misc

Supports a trouble that is not identifiable by any other codes. This code should be used only when necessary.

CR (Customer Report)

outOfFrame/OOF/misc

Line errors that alter the framing pattern are detected.

CR (Customer Report)

permanentSignal/CCR/ndt

Permanent signal is being generated within the signaling system or signaling equipment (for example, wink start, ground start, loop start, CCS7, SS7).

CR (Customer Report)

phaseJitter/JIT/data

An unwanted change in phase or frequency of a transmitted signal-generally characterized by a continuous time variation in the zero crossings of a sine wave or pulsed signal.

CR (Customer Report)

release/RLS/misc

Work performing an activity that will cause a service interruption.

RL (Release)

releaseCktRequestedByEC/
RLS/misc

The LEC is performing an activity that will cause a service interruption and is notifying the IC to request a convenient time and date from the bill-paying customer for the circuit to be idle. Required any time the LEC is performing internal work that will cause an out-of-service condition to the circuit.

RL (Release)

releaseCktRequestedByIC/
RLS/misc

The IC is performing an activity that will cause a service interruption and is notifying the LEC.

RL (Release)

releaseFacRequestedByEC/
RLS/misc

The LEC is performing an activity which will cause a service interruption to a facility used to support access services and is notifying the IC to request a convenient time and date from the bill-paying customer for the circuit to be idle. Required any time the LEC is performing internal work which will cause an out-of-service condition to a circuit.

RL (Release)

releaseFacRequestedByIC/
RLS/misc

The IC is performing an activity which will cause a service interruption to a HiCap or interoffice facility and is notifying the LEC; may be used to inform the LEC to disregard alarms on a HiCap circuit.

RL (Release)

requestDispatch/DISP/misc

The customer is requesting an automatic dispatch and is waiving testing requirements prior to the dispatch.

CR (Customer Report)

requestForRoutine/RFR/misc

A release of the circuit or trunk is being requested to perform routine.

CR (Customer Report)

requestMonitorOfCircuit/
MON/misc

A request for a non-intrusive monitoring device to be connected to the circuit for a specified period of time. The monitoring device could be in the Central Office or at the premises location. Normally requested on chronic circuits.

AT (Assist Test)

seizureOnCircuit/SZR/misc

Circuit appears to be working in all directions, except for the presence of a constant seizure.

CR (Customer Report)

slip/SLP/data

Frames are missing or arrived out of sequence.

CR (Customer Report)

slowDialTone/SDT/ndt

When the telephone goes off-hook, the dial tone is not heard immediately.

CR (Customer Report)

slowResponse/SLO/data

Not receiving the data in the expected time interval; possibly caused by error detection.

CR (Customer Report)

staticOnLine/SOL/misc

There is static or noise on the voice line.

CR (Customer Report)

supervision/SUP/misc

A lack, abuse, or improper functioning of supervision processes or supervision configuration setting (for example, improper wiring for E&M signaling, ground start signaling, or improper software/hardware DSU/CSU configuration settings established to perform signaling functions between CPE equipment and network transmission, multiplexing, or switching equipment).

CR (Customer Report)

Trouble Type Abbreviation	Description	Report Category
alarm/ALM/misc	A trouble on a circuit has been identified by alarm equipment within a LEC Central Office.	CR (Customer Report)
biPolarViolations/BPV/misc	A condition which occurs when a bit stream contains a pulse of the same polarity as the previous pulse and which is not part of the bipolar zero substitution code.	CR (Customer Report)
canNotBeSignalled/CBS/misc	The connecting circuit's signaling equipment is defective. It does not allow a circuit connect to occur.	CR (Customer Report)
canNotMeet/CMT/misc	A failure of intercom conference channel equipment's ability to establish bridged connections.	CR (Customer Report)
canNotReceiveData/CRD/ data	A modem cannot receive data when connected to a destination modem via the circuit.	CR (Customer Report)
canNotSendData/CSD/data	A modem cannot send data when connected to a destination modem via the circuit.	CR (Customer Report)
canNotSignal/CSO/misc	The premises customer's circuit does not provide signals to allow a connection to occur (for example, wink start, ground start, loop start, CCS7, SS7).	CR (Customer Report)
canNotTransmitCanNotRecv/NTR/data	A modem can neither send nor receive data when connected to a destination modem via the circuit.	CR (Customer Report)
circuitDead/CKD/ndt	No dial tone is provided when the telephone goes off-hook.	CR (Customer Report)
circuitDown/DWN/misc	There is no activity on the circuit at all. The circuit shows no sign of continuity with the service provider.	CR (Customer Report)
circuitInLoopBack/CIL/data	Unable to receive test signal from a device with loopback capabilities.	CR (Customer Report)
cutsOff/CTO/tran	Voice service user experiences an interruption during the course of service use.	CR (Customer Report)
dataFramingErrors/FRM/data	Line errors which alter the framing pattern and cause the receiver to react as if it were out of frame are present.	CR (Customer Report)
delay/DEL/misc	Usually referred to as Envelop Delay Distortion (EDD). EDD is the distortion of a signal due to differences in propagation of different frequencies which comprise the data signal. EDD is determined by measuring the delay of various frequencies, within the band of interest, with respect to a reference frequency. Absolute delay generally has little effect on data transmission.	CR (Customer Report)
dropOuts/DPO/data	The decrease in receiving signal level is equal to or greater than 12dB and lasts more than four milliseconds.	CR (Customer Report)
echo/ECO/tran	Improperly engineered echo suppressors or echo cancellers, or absence of such equipment in the Central Office facilities/equipment, cause voice echo during conversations.	CR (Customer Report)
errors/ERR/data	Errors in the data signal are detected (such as LRC-CRC errors).	CR (Customer Report)
failingCircuit/FLD/misc	Frequency tones fail to reach the distant end. Non-descriptive code.	CR (Customer Report)
gettingAllOnes/GAO/data	The bit stream indicates the line is out of service.	CR (Customer Report)
grounded/GRD/misc	A DC ground is on the wire or equipment. Often causes noise, off-hook, or garbled signal.	CR (Customer Report)
highLevels/HOT/tran	Normally, a reference to data services. Levels are smaller in reference to 0dB as shown on the engineering design.	CR (Customer Report)
historicalReports/INF/misc	Defined by local (inter-exchange carrier) practice.	CR (Customer Report)
hits/HIT/data	Sudden variation in receiving signal amplitude is equal to or greater than 3dB, and lasts more than four milliseconds.	CR (Customer Report)
hollow/HOL/tran	Improperly engineered transmission equipment power levels, load coils, echo suppressers, or echo cancellers, or the absence of such equipment for the transmission of the signal.	CR (Customer Report)
impulseNoise/IMP/misc	Large amplitude peaks that occur unpredictably in infrequent bursts against the data carrier background that produce error impairments in the data signal.	CR (Customer Report)
information/INF/misc	The circuit is not out of service. The customer is requesting attention and/or providing information outside of the normal trouble clearance process.	IN (Information)
invalidData/INV/data	Error message indicating possible bad or incorrect parameters.	CR (Customer Report)
lossOfSync/OOS/misc	In superframe (SF), once in sync, two of the last five framing bits (Ft) are in error. In extended superframe (ESF), once in sync, two of the last five framing pattern sequence bits are in error. (Intermittent)	CR (Customer Report)
lowLevels/LOW/tran	User cannot hear conversation because the voice is too low.	CR (Customer Report)
modem/STR/phys	The modem is defective or not responding. Modems can be in either the LEC Central Office or at the customer premises.	CR (Customer Report)
monitorCircuit/MON/misc	Request for a non-intrusive monitor to be placed on the circuit for a specified period to capture intermittent failures.	AT (Assist Test)
noAnswerBack/NAB/misc	No response from the far-end customer premises equipment.	CR (Customer Report)
noCarrier/NCR/data	Unable to detect the carrier signal from the far end.	CR (Customer Report)
noContinuity/NCN/misc	Inability of the transmission equipment to pass a DC continuity check to ensure the existence of an uninterrupted electrical signal for the channel or channels.	CR (Customer Report)
noDialTone/NDT/ndt	No audible dial tone is provided when the telephone goes off-hook.	CR (Customer Report)
noLoopBack/NLB/misc	Unable to receive test signal from a device with loop-back capabilities.	CR (Customer Report)
noSignal/NOS/misc	The circuit appears to be working in all directions, except for the absence of signaling.	CR (Customer Report)
offHook/OHK/phys	A telephone set or signaling equipment at the premises is causing an off-hook condition. The trouble identified might be a reorder or dead air on the line.	CR (Customer Report)
open/OPX/ndt	The circuit will not allow a DC signal to pass through it; often, an open wire or defective equipment anywhere within the circuit.	CR (Customer Report)
orderWork/ORD/misc	Customer's service has never worked, usually follows a recently closed service order to complete the provisioning process, when necessary.	CR (Customer Report)
other/OTH/misc	Supports a trouble that is not identifiable by any other codes. This code should be used only when necessary.	CR (Customer Report)
outOfFrame/OOF/misc	Line errors that alter the framing pattern are detected.	CR (Customer Report)
permanentSignal/CCR/ndt	Permanent signal is being generated within the signaling system or signaling equipment (for example, wink start, ground start, loop start, CCS7, SS7).	CR (Customer Report)
phaseJitter/JIT/data	An unwanted change in phase or frequency of a transmitted signal-generally characterized by a continuous time variation in the zero crossings of a sine wave or pulsed signal.	CR (Customer Report)
release/RLS/misc	Work performing an activity that will cause a service interruption.	RL (Release)
releaseCktRequestedByEC/ RLS/misc	The LEC is performing an activity that will cause a service interruption and is notifying the IC to request a convenient time and date from the bill-paying customer for the circuit to be idle. Required any time the LEC is performing internal work that will cause an out-of-service condition to the circuit.	RL (Release)
releaseCktRequestedByIC/ RLS/misc	The IC is performing an activity that will cause a service interruption and is notifying the LEC.	RL (Release)
releaseFacRequestedByEC/ RLS/misc	The LEC is performing an activity which will cause a service interruption to a facility used to support access services and is notifying the IC to request a convenient time and date from the bill-paying customer for the circuit to be idle. Required any time the LEC is performing internal work which will cause an out-of-service condition to a circuit.	RL (Release)
releaseFacRequestedByIC/ RLS/misc	The IC is performing an activity which will cause a service interruption to a HiCap or interoffice facility and is notifying the LEC; may be used to inform the LEC to disregard alarms on a HiCap circuit.	RL (Release)
requestDispatch/DISP/misc	The customer is requesting an automatic dispatch and is waiving testing requirements prior to the dispatch.	CR (Customer Report)
requestForRoutine/RFR/misc	A release of the circuit or trunk is being requested to perform routine.	CR (Customer Report)
requestMonitorOfCircuit/ MON/misc	A request for a non-intrusive monitoring device to be connected to the circuit for a specified period of time. The monitoring device could be in the Central Office or at the premises location. Normally requested on chronic circuits.	AT (Assist Test)
seizureOnCircuit/SZR/misc	Circuit appears to be working in all directions, except for the presence of a constant seizure.	CR (Customer Report)
slip/SLP/data	Frames are missing or arrived out of sequence.	CR (Customer Report)
slowDialTone/SDT/ndt	When the telephone goes off-hook, the dial tone is not heard immediately.	CR (Customer Report)
slowResponse/SLO/data	Not receiving the data in the expected time interval; possibly caused by error detection.	CR (Customer Report)
staticOnLine/SOL/misc	There is static or noise on the voice line.	CR (Customer Report)
supervision/SUP/misc	A lack, abuse, or improper functioning of supervision processes or supervision configuration setting (for example, improper wiring for E&M signaling, ground start signaling, or improper software/hardware DSU/CSU configuration settings established to perform signaling functions between CPE equipment and network transmission, multiplexing, or switching equipment).	CR (Customer Report)