5.2 Cable Connectivity Issues and Appropriate Tools

Question 1

What is the Throughput of a cable installation?

Answer 1

The usable bandwidth that the installation will provide.

Question 2

What is the Speed of a connection?

Answer 2

The wire speed of the connection and potentially the speed a connection can burst up to.

Question 3

How is the distance of a cable installation defined?

Answer 3

By the cable installation specifications and often noted in meters.

Question 4

What are the most common cables used in networks today?

Answer 4

Unshielded Twisted-pair (UTP) and Shielded Twisted-pair.

Question 5

Which cabling is used in networks with high amounts of EMI from machinery?

Answer 5

Shielded Twisted-pair, usually used in industrial Ethernet circumstances and is much more expensive that UTP.

Question 6

What is PVC Jacketed cabling?

Answer 6

Also called riser-rated cable, has a plastic that when burned can cause irritation in the lungs and eyes.

Question 7

What is Plenum cable?

Answer 7

Cable coated with a fire-retardant coating that is usually Teflon-based.

Question 8

Which cable is specified in the electrical and fire code for use in airspace that provides ventilation or air-conditioning?

Answer 8

Plenum-rated cable.

Question 9

What is a Rollover cable.

Answer 9

Also known as a console cable, is a flat stock telephone cable that is crimped on both ends with RJ-45 connectors.

Question 10

How is a Rollover cable configured?

Answer 10

One side is crimped starting at pin 1 and the opposite end is crimped starting at pin 8. So, pin 1 maps to 8, pin 2 maps to 7, and so on

Question 11

What is a Crossover cable?

Answer 11

Allows for the transmit pins of the cable to be crossed over to the receive pins on the opposite computer.

Question 12

When a Crossover cables used.

Answer 12

They are useful when connecting the same type devices together without the use of a switch or hub, such as computers.

Question 13

What is the Power Over Ethernet PoE (802.3af) standard?

Answer 13

It is used to supply up to 15.4 watts of power over Ethernet cable. It is commonly used with phone and video surveillance cameras.

Question 14

What is the PoE+ (802.3at) standard?

Answer 14

It is used to supply up to 25.5 watts of power over Ethernet.

Question 15

What is Attenuation?

Answer 15

The loss of signal strength in networking cables and connections. Common in RF cabling such as coaxial cabling, not common in Ethernet networks.

Question 16

What is Electrical Magnetic Interference (EMI)?

Answer 16

It is generated by radio frequency (RF) devices, large motors, and high-voltage lines.

Question 17

How can Electrical Magnetic Interference (EMI) be counteracted?

Answer 17

By using Shielded Twisted-pair (STP) wiring.

Question 18

What is Decibel (dB) loss?

Answer 18

A measurable loss in signal on a cable.

Question 19

What is Incorrect Pinout?

Answer 19

Generally associated with serial cables, the pinout can be checked with a Multimeter.

Question 20

What should happen when a Bad Port on a network switch is identified?

Answer 20

The equipment should be replaced so that time is not wasted in the future on diagnosing a bad port.

Question 21

What are Open Conditions in a wire?

Answer 21

It means that a wire is not making a connection, which can happen if a connector comes loose or a wire breaks.

Question 22

Ho do Shorts happen?

Answer 22

When two wires make a connection, this can happen if the insulation on the wires wears off or a foreign object is run into the wiring.

Question 23

What is Transceiver mismatch?

Answer 23

It happens when the other transceiver does not match the expected wavelength on both ends.

Question 24

What happens when the transmit and receive fiber-optic cable is reversed?

Answer 24

When this happens, the link will not turn up.

Question 25

What are Crimpers used for?

Answer 25

To crimp RJ-45 ends on network cabling.

Question 26

What is a Punch-down Tool used for?

Answer 26

To punch the wire of the network cable in to the patch panel or female cable end.

Question 27

What is a Tone Generator used for?

Answer 27

Locating network cabling with a signal probe.

Question 28

What is a Fiber-optic Loopback used for?

Answer 28

To loop one end of the fiber-optic cable so that testing can be done end to end.

Question 29

What is an Optical Time-domain Reflectometer (OTDR) used for?

Answer 29

To measure the length of fiber-optic cable and identify breaks in it.

Question 30

What is a Multimeter used for?

Answer 30

Commonly used to test power at outlets and power supplies and to test continuity in low-voltage wiring circuits.

Question 31

What is a Cable Tester used for?

Answer 31

To test patch cables and network cabling with male RJ-45 ends.

Question 32

What is a Wire Mapper?

Answer 32

Similar to a cable tester but also details which wire needs to be repaired in the event of a mis-wire.

Question 33

What is a Tap used for?

Answer 33

Allows network equipment to tap into the signal so a tech can capture traffic.

Question 34

What is a Fusion Splicer?

Answer 34

A device that fuses glass fiber together to splice fiber-optic cable together.

Question 35

What is a Spectrum Analyzer?

Answer 35

It helps the administrator see the radio frequency (RF) spectrum and is often used to diagnose wireless interference problems.

Question 36

What are Snips and Cutters used for?

Answer 36

To cut cabling and the components of a cable.

Question 37

What are Cable Strippers?

Answer 37

They allow the technician to remove the sheathing of the cable.

Question 38

What is a Light Meter?

Answer 38

It allows the administrator to measure the amount of signal loss in a fiber-optic cable.