Troubleshooting Wireless Issues

Question 1

What is Cat5 also known as?

Answer 1

Fast Ethernet or 100BASE-TX

Operates at 100 Mbps up to 100 meters

Question 2

What is the maximum speed and distance of Cat5e?

Answer 2

1000 Mbps/1 Gbps up to 100 meters

Also known as Gigabit Ethernet or 1000BASE-T

Question 3

What does Cat6 support in terms of speed and distance?

Answer 3

1 Gbps up to 100 meters, or 10 Gbps up to 55 meters

Also known as 1000BASE-T/10GBASE-T

Question 4

What is the maximum speed of Cat6a/Cat7 cables?

Answer 4

10 Gbps up to 100 meters

Also known as 10GBASE-T

Question 5

What is the maximum speed and distance of Cat8 cables?

Answer 5

40 Gbps up to 30 meters

Also known as 40GBASE-T

Question 6

What is the maximum speed of coaxial cables?

Answer 6

Up to 100 Mbps up to 500 meters

Coaxial cables are used in various applications

Question 7

What is the maximum speed of twin axial cables?

Answer 7

Supports speeds up to 10 Gbps, limited to 5 meters

Newer versions can reach 100 Gbps up to 7 meters

Question 8

What does multimode fiber support at 100BASE-FX?

Answer 8

100 Mbps up to 2 kilometers

Also supports 100BASE-SX and 1000BASE-SX

Question 9

What is the maximum distance for single mode fiber at 10GBASE-LR?

Answer 9

10 kilometers

Also supports 1000BASE-LX at 1 Gbps up to 5 kilometers

Question 10

What is the difference between shielded and unshielded twisted pair cables?

Answer 10

Shielded offers more protection from EMI but is more expensive

Unshielded cables are less expensive

Question 11

What are plenum cables used for?

Answer 11

Used horizontally in spaces between ceilings and floors

Have higher fire ratings

Question 12

What type of cable connects a computer terminal to a router’s console port?

Answer 12

Rollover/Console Cables

A type of null-modem cable for out-of-band communication

Question 13

What technology allows electrical power to be passed over Ethernet cables?

Answer 13

Power over Ethernet (PoE)

Requires at least Category 5e cables

Question 14

What is attenuation in the context of network cables?

Answer 14

Loss of signal strength over the length of the cable

Commonly affects copper cables

Question 15

What is the maximum distance for twisted pair cables due to attenuation?

Answer 15

About 100 meters

Coaxial cables can reach about 500 meters

Question 16

What factors affect attenuation?

Answer 16

Distance, frequencies used, noise in the environment, physical surroundings

Each factor contributes to signal degradation

Question 17

What measures the amount of signal deterioration on a connection?

Answer 17

Decibel (dB) Loss

Higher dB loss indicates more signal deterioration

Question 18

What tool measures attenuation and dB loss on network cables?

Answer 18

Cable Certifier

Essential for testing cable signal integrity

Question 19

What indicates that a network port has been intentionally disabled by administrators?

Answer 19

Administratively Down Port Status

Different from Error Disabled Port Status

Question 20

What is a common issue that occurs when one device thinks the connection is full duplex and the other thinks it is half duplex?

Answer 20

Duplex Mismatch

Symptoms include high packet loss and high receive error rate

Question 21

What is one method to mitigate dB loss in cables?

Answer 21

Use higher quality cables or clean connectors

Ensures better signal quality

Question 22

What occurs when there is a break in the wires between the source and destination?

Answer 22

Open

A type of connectivity issue

Question 23

What is the cause of ‘drops’ in network performance?

Answer 23

Device’s buffer is full, can’t accommodate incoming frames

Caused by high network traffic or capacity issues

Question 24

What is the purpose of a fiber light meter?

Answer 24

Tests for attenuation on and dB loss fiber connections

Helps in diagnosing fiber cable issues

Question 25

What is the resolution for a Power Budget Exceeded Error?

Answer 25

Check and compare power requirements of devices with total power budget available ## Footnote Consider removing non-essential devices

Question 26

What happens if the wrong transceiver is used in a fiber connection?

Answer 26

The connection won't work ## Footnote Many transceivers are hot-pluggable

Question 27

What can cause performance issues in fiber optic cables?

Answer 27

Dirty Optical Cables ## Footnote Even small particles can block light transmission

Question 28

What are the two types of cleaning methods for fiber optic cables?

Answer 28

* Dry cleaning * Wet cleaning ## Footnote Each method serves to maintain optimal performance

Question 29

What is a symptom of noise interference in network cables?

Answer 29

Cyclical Redundancy Check (CRC) Errors ## Footnote Indicates data corruption or alteration

Question 30

What is a total power budget in PoE?

Answer 30

The total power budget available for devices connected via Power over Ethernet (PoE). ## Footnote Consider removing non-essential devices or upgrading the PoE source

Question 31

What occurs with an incorrect PoE standard?

Answer 31

A mismatch between the PoE standard supported by the end device and the switch. ## Footnote Resolution includes checking compatibility and possibly replacing the switch or using PoE injectors.

Question 32

What is a PoE injector?

Answer 32

A device that adds electrical power to a standard Ethernet data cable to provide both power and data to PoE-capable endpoint devices.

Question 33

What are symptoms of PoE issues?

Answer 33

Devices may randomly restart, behave erratically, or refuse to power on.

Question 34

What does RSSI stand for?

Answer 34

Received Signal Strength Indicator.

Question 35

What does EIRP stand for?

Answer 35

Effective Isotropic Radiated Power.

Question 36

What is RSSI used to measure?

Answer 36

The power level that a radio frequency client device is receiving from a wireless access point or router.

Question 37

What are the RSSI levels for signal strength?

Answer 37

* Over -90 dB - Extremely weak * Around -65 dB - Fairly strong * -55 dB - Strong * -30 dB - Extremely strong.

Question 38

What is wireless coverage?

Answer 38

The measure of the area around a wireless transmitter with sufficient signal strength for device use.

Question 39

What is a wireless site survey?

Answer 39

A method to create a heat map showing signal strength levels to assess wireless coverage.

Question 40

What are common coverage issues in wireless networks?

Answer 40

Insufficient coverage in multi-story buildings due to signal degradation with distance and obstacles.

Question 41

How can coverage be improved in wireless networks?

Answer 41

* Use signal boosters * Antennas with higher dBi ratings.

Question 42

What is an Extended Service Set (ESS)?

Answer 42

Combining multiple access points into a single network with seamless roaming for devices.

Question 43

What are wireless repeaters?

Answer 43

Layer one devices with two radios that receive and retransmit signals at full strength to extend coverage.

Question 44

What causes interference in wireless networks?

Answer 44

When multiple wireless networks communicate on the same channel at the same frequency.

Question 45

What channels should be used to avoid overlap in 2.4 GHz networks?

Answer 45

Channels 1, 6, and 11.

Question 46

What is attenuation in wireless networks?

Answer 46

Reduction of signal strength between transmission and reception.

Question 47

What are causes of attenuation?

Answer 47

* Distance * Physical obstacles * Signal interference.

Question 48

What is multipath reception?

Answer 48

Occurs when signals bounce off objects, causing attenuation and weaker signals.

Question 49

What is idle timeout in wireless networks?

Answer 49

Occurs after 300 seconds (5 minutes) of inactivity, leading to client disassociation.

Question 50

What is a captive portal?

Answer 50

A webpage displayed to newly connected users of a wireless network for authentication and access control.

Question 51

What is the purpose of a captive portal?

Answer 51

* Authentication * Payment * Acceptance of agreements * Survey completion * Other information collection.

Question 52

What is the common issue with captive portals on devices?

Answer 52

Smartphones and laptops may not automatically load the captive portal.

Question 53

What types of antennas are used in wireless networks?

Answer 53

* Omnidirectional * Dipole * Yagi * Parabolic Grid/Disk.

Question 54

What is channel utilization in wireless networks?

Answer 54

A statistic or measure of airtime utilization for a frequency or channel.

Question 55

What are the seven steps of wireless access point association?

Answer 55

* Wireless client sends a probe request * Access point checks data rate support * Client sends authentication frame * Access point acknowledges * Client sends association request * Access point processes the request * Client is fully connected.

Question 56

What is the effect of higher channel utilization?

Answer 56

Higher utilization indicates more traffic, which may lead to slower wireless network speeds.