Module 4

Question 1

Components of an access point

Answer 1

1. The wireless antennas
2. Several Ethernet switchports
3. An internet port

Question 2

NIC

Answer 2

Network interface card
Ethernet NICs for wired connection
WLAN NICs for wireless

Question 3

Three functional areas of the physical layer

Answer 3

Physical Components
Encoding
Signaling

Question 4

Terms used to measure the quality of bandwidth

Answer 4

Latency
Throughput
Goodput

Question 5

Latency

Answer 5

The amount of time, including delays, for data to travel from one given point to another

Question 6

Throughput

Answer 6

Throughput is the measure of the transfer of bits across the media over a given period of time
Usually lower than the bandwidth

Question 7

Goodput

Answer 7

The measure of usable data transferred over a given period of time
Throughput minus traffic overhead from acknowledgements, encapsulation etc

Question 8

UTP cable

Answer 8

Unshielded twisted - Most common network medium
Four pairs of twisted color-coded wires
Outer jacket protect wires from physical damage
Twisted pairs protect signal from interference
Insulation isolates wires and identifies each pair

Question 9

STP

Answer 9

Shielded twisted pair
Four twisted pairs, each wrapped in a foil shield
All wrapped in an overall metallic braid or foil
Covered with a cable jacket to prevent minor physical damage

Question 10

Wireless

Answer 10

Uses patterns of microwaves to represent bits

Question 11

Fiber-optic

Answer 11

Uses light to represent bits

Question 12

Copper

Answer 12

Uses electrical pulses to represent bits

Question 13

Bandwidth

Answer 13

The capacity of a medium to carry data

Question 14

EMI

Answer 14

Electromagnetic interference

Question 15

RFI

Answer 15

Radio frequency interference

Question 16

Potential sources of EMI and RFI

Answer 16

Radio waves and electromagnetic devices, e.g. fluorescent lights or electric motors

Question 17

Crosstalk

Answer 17

A disturbance caused by the electric or magnetic fields of a signal on one wire to the signal in an adjacent wire.

Question 18

Coaxial cable

Answer 18

Single copper conductor surrounded by a layer of flexible plastic insulation, a woven copper braid, and a cable jacket

Question 19

Coaxial cables are used for:

Answer 19

Wireless installations

Cable internet installations

Question 20

UTP limits crosstalk by:

Answer 20

When two wires in a circuit are twisted togehter, their magnetic fields cancel each other out
Twisting each braid a different number of times

Question 21

Ethernet Straight-Through

Answer 21

Used to interconnect a host to a switch and a switch to a router

Question 22

Ethernet Crossover

Answer 22

A cable used to interconnect similar devices (considered legacy)

Question 23

Pros/cons of fiber-optic cable

Answer 23

Expensive

Transmits data further and at higher bandwidths than any other networking media

Question 24

SMF

Answer 24

Single mode fibre
Very small core, uses a laser to send a single straight ray of light
Travels ~100km

Question 25

MMF

Answer 25

Multimode fibre
Larger core, uses LED emitters to send light pulses at different angles
Travels ~500m
Commonly used on LANs

Question 26

Four uses of fiber-optic cabling

Answer 26

Enterprise networks
Fiber-to-the-home (FTTH)
Long-Haul Networks
Submarine Cable Networks

Question 27

Limitations of wireless

Answer 27

Coverage area limited by building materials
Interference by common devices
Security
Shared medium - half-duplex

Question 28

Wireless Standards

Answer 28

WiFi
Bluetooth - Distance 1-100m, used for Personal Area Networks
WiMAX - Point-to-multipoint topology
Zigbee - Low-data, low-power, commonly used for IoT and industrial environments

Question 29

Devices required for WLAN

Answer 29

Wireless Access Point - connects wireless to copper

Wireless NIC adapters - provides wireless capability to network hosts