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Question 1

What does CSMA/CA stand for?

Answer 1

Carrier Sense Multiple Access with Collision Avoidance

It is a wireless protocol used to manage how devices communicate over a network.

Question 2

In CSMA/CA, what must the channel be before a device can send a message?

Answer 2

Idle

This means that there is no other communication taking place on the channel.

Question 3

What is the first step in the CSMA/CA process?

Answer 3

Listen to the frequency band

This step checks for the presence of any other signals before sending a message.

Question 4

What happens if a device detects an existing transmission on the channel in CSMA/CA?

Answer 4

Wait for a random amount of time

This is part of the collision avoidance strategy.

Question 5

What must the sender receive after transmitting data in CSMA/CA?

Answer 5

Acknowledgement message

This verifies that the data was received successfully.

Question 6

What is the hidden node problem in wireless networks?

Answer 6

Interference with data transmission due to devices being out of range of each other’s broadcasts

This can lead to data collisions when multiple devices send data simultaneously.

Question 7

What are the two optional methods used to alleviate the hidden node problem?

Answer 7

• Request to Send (RTS)
• Clear to Send (CTS)

These methods help manage communication and reduce collisions but may introduce additional overhead.

Question 8

What is sent after determining the channel is idle in the RTS/CTS method?

Answer 8

Request to Send (RTS)

This signal indicates that a device wants to send data.

Question 9

What does the device send back in response to an RTS signal?

Answer 9

Clear to Send (CTS)

This reply allows the original sender to transmit its message without interference.

Question 10

In the RTS/CTS process, what happens if a CTS is not received?

Answer 10

The sender does not transmit data

This ensures that the channel remains clear for the intended transmission.

Question 11

What is the purpose of WiFi?

Answer 11

To enable wireless communication between devices using radio waves

WiFi revolutionised interconnecting devices without dedicated cabling.

Question 12

What are the two most common frequencies for WiFi radio signals?

Answer 12

• 2.4GHz
• 5.0GHz

Each frequency has different speed capabilities and coverage ranges.

Question 13

What is a wireless access point (WAP)?

Answer 13

A device that allows devices to connect to a WiFi network

WAPs typically connect to the internet via a cabled connection.

Question 14

What happens when a WiFi channel becomes crowded?

Answer 14

Network speed slows down

The router can be set to another channel to alleviate the issue.

Question 15

What is the primary security concern with WiFi networks?

Answer 15

Data can be intercepted by eavesdroppers

This is due to the nature of radio wave transmission.

Question 16

What does encryption do in a WiFi network?

Answer 16

Scrambles data to make it unreadable to unintended recipients

This is a key security measure for protecting data.

Question 17

What are the three main types of WiFi encryption?

Answer 17

• WEP
• WPA
• WPA2

Each type offers varying levels of security.

Question 18

What does WEP stand for?

Answer 18

Wired Equivalent Privacy

WEP was designed to provide security comparable to wired networks.

Question 19

What is a key feature of WPA compared to WEP?

Answer 19

Introduces key management with a new encryption key for each data packet

This enhances security against potential intruders.

Question 20

What is the improvement of WPA2 over WPA?

Answer 20

Provides an even stronger encryption algorithm

Each message is encrypted several times based on key size.

Question 21

What is a Service Set Identifier (SSID)?

Answer 21

A string of alphanumeric characters used to differentiate wireless networks

SSIDs are case sensitive and can include spaces and underscores.

Question 22

True or false: An SSID is always broadcast for all to see.

Answer 22

TRUE

However, SSIDs can be hidden for added security, though this is not foolproof.

Question 23

What is a limitation of wired networks compared to WiFi?

Answer 23

Limited by the length of cable used

Ethernet is often restricted to cable runs of 100m due to interference.

Question 24

What is one benefit of WiFi over wired connections?

Answer 24

Allows devices to be moved wherever is convenient

This flexibility enhances network usability.

Question 25

What is the **structure of the Internet**?

Answer 25

A global network of interconnected networks using common standards and protocols ## Footnote These networks are owned and managed by national governments, private companies, and academic institutions.

Question 26

What is the **internet backbone**?

Answer 26

A mesh of super fast fibre-optic cables and industrial routers ## Footnote It moves data at high speeds and is primarily provided by giant telecommunication companies.

Question 27

How do individuals and organizations connect to the Internet?

Answer 27

Through an **internet service provider (ISP)** ## Footnote Connections may be ADSL, fibre-optic, or via mobile technologies like 3G/4G.

Question 28

What is a **network access device**?

Answer 28

A device supplied by the ISP that connects home networks to the service provider ## Footnote It typically includes an ethernet switch, wireless access point, router, and modem.

Question 29

What is a **local area network (LAN)**?

Answer 29

A network covering a small geographic area, such as a home or school ## Footnote It connects users through a wireless access point or router.

Question 30

What defines a **wide area network (WAN)**?

Answer 30

A network that connects multiple local area networks (LANs) ## Footnote Examples include company networks across different buildings or cities.

Question 31

What is a **virtual private network (VPN)**?

Answer 31

A secure connection over the internet between sites ## Footnote It allows data to be sent as if devices were directly connected to a private network.

Question 32

What technologies are used to connect networks to form the **internet**?

Answer 32

* Ethernet * ADSL * Coaxial * Fibre optics * 4G/5G * Wireless * Satellite * Undersea cable * Powerline transmission ## Footnote These connections create an interconnected global network.

Question 33

What is the role of a **router** in networking?

Answer 33

To forward data packets between computer networks ## Footnote Different types of routers serve various functions in network connectivity.

Question 34

What are **core routers**?

Answer 34

Routers that are part of the internet backbone with multiple high-speed interfaces ## Footnote They handle large volumes of data traffic.

Question 35

What is the function of **edge routers**?

Answer 35

To link one network to another ## Footnote They serve as a bridge between different networks.

Question 36

What are **subscriber routers**?

Answer 36

Routers provided to homes and small businesses ## Footnote They are low-cost devices with two interfaces for network connection.

Question 37

What distinguishes **enterprise routers**?

Answer 37

They connect large businesses and ISP networks to the internet ## Footnote These routers are powerful and capable of handling high data volumes.