Networks

Question 1

What is a network?

Answer 1

Anetworkis a group of devices connected together so they can communicate with each other and share resources.

Question 2

How large is a network?

Answer 2

Networks can vary hugely in terms of size and complexity. Mobile hotspots and the internet are examples.

Question 3

State benefits of a network.

Answer 3

• Share data and information
• Communicate using email, messaging, video conferencing
• Work collaboratively using work-based software, virtual meeting tools, etc.
• Share hardware e.g. printers
• Use centralised support and maintenance
• Socialise with one another

Question 4

What is a standalone computer?

Answer 4

It “stands alone”, without connections to other computers or networks.

Question 5

What are the benefits of a standalone computer?

Answer 5

They are not considered useful today, but can be used to store sensitive files as they can only be hacked manually, or to test the severity of ransomware/viruses.

Question 6

What’s a WAN?

Answer 6

Networks that are connected over a large geographical area are known as Wide Area Networks (WANs).

Question 7

An example of a WAN

Answer 7

The largest example of a WAN is the internet. Examples of WANs are online banking.

Question 8

What organisation specific hardware does a WAN involve?

Answer 8

• Organisations that run their own WANs will often lease bandwidth from telecommunications companies. They own this and have full control of the network.
• Others cannot use its’ infrastructure, making it secure. However, the infrastructure can be expensive to install and maintain.

Question 9

What’s a LAN?

Answer 9

Networks that span a smaller geographical area that are contained within a single site or building are known as Local Area Networks (LANs)

Question 10

What does the “L” refer to in “LAN”?

Answer 10

‘Local’ doesn’t refer to a specific geographical area, such as neighbourhood, city, or region.

Question 11

What organisation specific hardware does a LAN involve?

Answer 11

In larger organisations (schools, colleges) infrastructure (cabling and network communication devices) will be owned and maintained by the organisation.

Question 12

How do addresses work on a LAN?

Answer 12

• Each device on a network has a unique identifier, which is usually its IP address.
• The first part of this address is thenetwork ID, which will be the same for all of the devices on the network.
• Each device in a network needs a unique address so that connections can be made to it.

Question 13

What is IPv4?

Answer 13

The fourth version of internet protocol IPv4 allows 4.3b addresses. It uses 32-bit encoding.

Ran out of addresses for the world

Question 14

What is IPv6?

Answer 14

The sixth version of internet protocol

IPv6 allows for 340 * 10^38 addresses. It uses 128-bit encoding. They can therefore address a greater number of unique devices.

Question 15

What is an internet protocol?

Answer 15

Protocols are sets of rules (agreed standards) that govern the communication within devices.

For two devices to communicate, they must use the same protocol.

Question 16

What is bandwidth?

Answer 16

Bandwidth is the maximum amount of data that can be transmitted over a connection. It is a measurement of capacity measured in bps (bits per second)

Question 17

What is latency?

Answer 17

Latency is the time taken for a transmission to reach its destination. It is measured in milliseconds.

Question 18

What is ping?

Answer 18

Ping measures latency by making a transmission and tracking the time it takes to move from the server and back again.

Question 19

What are the bits per second conversions?

Answer 19

That

Question 20

What are the bit conversions?

Answer 20

That 2

Question 21

What is the equation to estimate transmission times?

Answer 21

That 3

Question 22

What is wireless transmission?

Answer 22

Microwaves and radio waves are frequently used to transmit data. This involves converting the binary data into an electromagnetic wave using a specific protocol.

Wi-Fi and Bluetooth are examples of the protocols that govern the conversion of data.

Question 23

What are some negatives concerning wireless transmission?

Answer 23

• Generally the range of wireless transmission is limited to a few metres.
• It is easily interrupted by other signals or physical obstacles.
• It has much lower bandwidth than wired connections which makes transfer slow.
• Security is a concern as wireless signals can be intercepted by others.

Question 24

What is a WLAN?

Answer 24

• WLANs are Wireless Local Area Networks.
• You probably have a WLAN at home.
• If you use Wi-Fi to connect your devices, that’s a WLAN.

Question 25

What is a WAP?

Answer 25

- In a WLAN, there will be a wireless access point (WAP) which sends and receives wireless transmissions to and from the other devices. - A WAP is usually part of a box you call the broadband router. - The router will be connected (usually wired) to an internet access point in order to connect the WLAN to the internet.

Question 26

Wired VS Wireless - Battle 1 Installation

Answer 26

WIRELESS WINS + Not every device needs a dedicated cable, cutting down cabling costs - Cables still need to be installed in ceilings and floors to get from the WAP to a switch - WAPS need to be purchased WIRED LOSES - Wired may be more difficult as every device needs a dedicated cable - Bugs are more difficult to diganose as all cabling needs inpection

Question 27

Wired VS Wireless - Battle 2 Flexibility

Answer 27

BOTH SUCK - Wired cannot move beyond the area covered by the cable - Wireless cannot leave a 2m radius

Question 28

Wired VS Wireless - Battle 3 Range

Answer 28

WIRED WINS + Transmission over longer distances as copper media is more effective - Wired may need repeaters or boosters greater than 100m as signal depreciates WIRELESS LOSES - Quality easily lost through walls, floors, barriers between WAP and node - Repeaters and boosters required due to small range

Question 29

Wired VS Wireless - Battle 4 Bandwidth

Answer 29

WIRED WINS + Higher bandwidth as copper media has better signal transmission than air WIRELESS LOSES -

Question 30

Wired VS Wireless - Battle 5 Latency

Answer 30

WIRED WINS + Less susceptible to interference from outside network due to cables having layers of covering WIRELESS LOSES - More susceptible to interference from outside networks as radio waves disperse over large distances, slowing data transfer

Question 31

What is topology?

Answer 31

The design/layout of a network

Question 32

Bus

Answer 32

A central node with stops coming off it

Question 33

Pros of bus topology

Answer 33

New devices can just be attached to the central node

Question 34

Cons of bus topology

Answer 34

Decreasing latency down the node → Everything stops off at each computer Hacking poses a more serious threat → Each device has access to all traffic

Question 35

Star

Answer 35

A central switch with spokes coming off it

Question 36

Pros of star topology

Answer 36

Far more secure if there is an intrusion → Data only passes through the switch and the computer → Each PC only recieves its’ own traffic Higher latency → Only one journey straight to each computer

Question 37

Cons of star topology

Answer 37

Limited amount of connections based on amount of ports in switch If the switch fails, all PCs connected are stranded - Central point of failiure

Question 38

Full mesh

Answer 38

All nodes connected to each other

Question 39

Pros of full mesh

Answer 39

Fault tolerance Reasonably secure → Traffic takes shortest route to get to its destination

Question 40

Cons of full mesh

Answer 40

High cabling costs

Question 41

Partial mesh

Answer 41

Some nodes connected

Question 42

Pros of partial mesh

Answer 42

Reasonably secure → Traffic takes shortest route to get to its destination

Question 43

Cons of partial mesh

Answer 43

Computers cannot talk to each other easily → Have to move through other computers reducing latency and bandwidth

Question 44

Where is bus topology used?

Answer 44

a small, cheap and often temporary network is needed that does not rely on very high data-transfer speeds. They may be used in locations such as a laboratory or office.

Question 45

Where is star topology used?

Answer 45

Home networks

Question 46

Where is a mesh topology used?

Answer 46

Home automation systems

Question 47

How is data transmitted on a fibre-optic cable?

Answer 47

A series of glass shards that allow light waves to move down them

Question 48

Define the World Wide Web

Answer 48

The service hosted on the internet to provide webpages

Question 49

Define the Internet

Answer 49

Physical devices that make up all networks connected across the world

Question 50

What do you need within a WAP to connect to the internet?

Answer 50

Switch Modem Router

Question 51

What is the internet backbone?

Answer 51

Fibre-optic cables that connect continents/countries under the sea with a high bandwidth