TROUBLESHOOTING TELEPHONE WIRING AND TWISTED-PAIR CABLE
How do short, an open, and a ground fault disrupt dial tone?
A short anywhere in the telephone wiring results in no dial tone to all CPE. An open in the telephone wiring results in selected pieces of equipment having no dial tone, depending on the location of the fault in the circuit and the wiring topology. A ground fault disables the ability of the network or EMTA to supply dial tone.
A minimum bending radius of no less than four times the cable diameter must be observed.
ANSI/TIA/EIA 570-B and ANSI/TIA/EIA 570-D
What is bus topology?
Also known as the "loop-through" topology, this topology connects each outlet in series, creating a loop.
How do you fix noise at a customers residence that has noise on the phone line in the house?
Check grounding or shielding problems in the station wiring. Also check for poor terminations, or poor grounding and bonding connections.
What can you do to fix ringer problems with the phone system at a customers residence?
Check if excessive ringer equivalence number (REN) totals are in the telephone circuit.
What can you do to fix continuous dialtone?
Confirm correct polarity of the telephone wiring.
What type of questions should the technician ask the customer during the identify and analyze stages of the six-step troubleshooting process?
During the identify and analyze stage of the six-step troubleshooting process, ask the customer about any work done on the premises and about any unusual events such as power outages or electrical storms prior to the problem, and if anyone has tried to fix the problem already.
How does environmental damage to UTP cable occur?
Environmental damage to UTP cable occurs when system components are subject to water, dirt, oil, sunlight (ultraviolet), air pollution, rodents, and so on.
What is the first thing you check when you have a no dial tone trouble call?
First confirm that the EMTA is working properly by connecting a telephone test set directly to the EMTA's telephone port.
What are the six steps of the troubleshooting process?
Gather information to identify the problem, analyze the problem, Isolate the problem area using measurements from various test instruments, diagnose the cause of the problem, resolve the problem, and test to verify the problem is fixed.
What is the significance of the REN rating when diagnosing a telephone number problem?
If the total REN of the telephones, fax machines, etc., connected to one telephone line exceeds the REN of the service, some or all of the ringers may not operate..
What is star topology?
If there is a bad connector between the network interface device (NID) and the customer premises equipment (CPE), the problem can be isolated to a single leg and quickly resolved.
What is cross-pinning?
In the configuration cross-pinning, to help maintain polarity throughout the telephone network, the wiring order of the two modular connectors installed on silver satin cable is typically reversed at opposite ends.
What is straight-through pinning?
In the configuration straight-through pinning,the modular connectors are wired in the same order at both ends of the cable.
What should be done if a transposition error is discovered when using a twisted-pair cable tester to locate a fault in a premises that is wired in the star topology?
Inspect the wiring order at the local connector before going to the opposite end and perform the same task. When cabled in the star topology, repeat the same process for each cable by moving the tester remote unit to each room that has a data outlet until all the cables have been tested.
What problems can be caused by using a USOC wiring configuration on a modular plug or jack used for data?
Problems caused by using a USOC wiring configuration on a modular data plug or jack include excessive crosstalk, impedance mismatches, and an unacceptable signal delay differential.
What are the two types of telephone station wiring typicall installed in customers premises.
Quad station wire and unshielded twisted-pair (UTP) cable are two types of station wire installed in customers premises.
What circuit condition in the telephone wiring can prevent touch-tone telephones from transmitting the DTMF tones used for tone dialing?
Reverse polarity in the telephone wiring can prevent some touch-tone telephones from transmitting the DTMF tones used for tone dialing.
What connectors are used in telephone cabling?
Straight-through pinning is typically used with 8P8C modular connectors and UTP cable to connect computers and modems to the local area network (LAN).
Which pinning configuration should be used when 8p8c modular connectors are installed on cables used for connecting computers and modems to the local area network (LAN)?
Straight-through pinning is used when 8P8C modular plugs are installed on cables used for connecting computers and modems to the local area network (LAN).
What are the four most commong types of telephone line noise?
The four most common types of telephone line noise are static, hum, crosstalk, and radio interference.
What are the three major topologies used for unshielded twisted-pair (UTP) cable installations?
The three major topologies for installing UTP cable are the star topology, the bus topology, and the hybrid topology.
What type of test equipment is designed specifically to test and diagnose twisted-pair cable?
The twisted-pair cable tester is designed specifically to test and diagnose twisted-pair cable and its connections.
What are the four major components of a telephone circuit in the customer premises?
The voltage/signal source, consisting of the NID/EMTA, the station wiring, the terminations, such as connectors, plugs, and jacks, and the CPE are the four major components of a telephone circuit in the customer premises.
How can transposition error occur?
Transpositions exist when a complete pair of wires are accidentally terminated where another pair should be terminated. This error is typical when an installer terminates one end of an installation in the T568A configuration and the other end in the T568B configuration.
what is hybrid topology?
When a problem occurs, it is possible to isolate groups of outlets from one another until the group containing the problem is identified using this topology.
Which of the following is true regarding troubleshooting twisted-pair wiring?
When diagnosing premises wiring, if there is voltage present at the NID/EMTA but none at the CPE, then there is a broken wire, an incorrectly wired termination, or a short in one of the connected CPE.
Which of the following is true regarding troubleshooting twisted-pair wiring?
When using the digital multimeter to isolate wiring issues, a shorted modular plug is connected to the wall jack at the opposite end of the cable being tested to verify continuity through the wiring. There should be no connectivity between paired pins until the shorted plug is connected.
When using a shorted modular plug to verify the connectivity of pairs in UTP cable, which pins on a modular plug breakout adapter should show low resistance on a DMM?
With the shorted modular plug connected, pins 4 and 5 (pair 1), 3 and 6 (pair 2), 1 and 2 (pair 3), and 7 and 8 (pair 4), all should measure near zero ohms of resistance on a DMM.
Minimum allowable proximity to power lines (2 inches) and avoiding sources of electromagnetic interference (EMI).
ANSI/TIA/EIA 570-B and ANSI/TIA/EIA 570-D
Requirements for adequate slack (8 inches) at the information service outlet/work area outlet (ISO/WAO) or telephone outlet and distribution device (DD).
ANSI/TIA/EIA 570-B and ANSI/TIA/EIA 570-D
Category 6A is the minimum recognized category of balanced twisted-pair cabling.
ANSI/TIA/EIA 570-D
Series 59 coaxial cabling is no longer a recognized media type for any grade cabling system.
ANSI/TIA/EIA 570-D
cat 5e/cat 6 cable have how many pairs
Four pairs
Quad Station wire has how many pairs
Two pairs
