3) Networks

Question 1

What is a LAN?

Answer 1

A local area network and covers a small geographical area on a single site.

Question 2

Things about LAN?

Answer 2

• owned by the organisation that uses it
• Either wired or wireless
• Find in schools ,businesses and universities

Question 3

Why would you use a LAN?

Answer 3

• Sharing files is easier and copy files between machines
• Can share same hardeware
• You can install and update software all at once
• users can log in from any device on the network

Question 4

What is a WAN?

Answer 4

Wide area network that connects all LANS

Question 5

Example of WAN?

Answer 5

When you want to connect businesses in different countries together

Question 6

Things about WAN?

Answer 6

• Expensive
• Internet is one big WAN

Question 7

What factors effect performance of networks?

Answer 7

• Greater the bandwith greater it can perform
• too many devices connected may cause conjestion
• Fibre optic cables give better performance

Question 8

Whats a client server?

Answer 8

Its managed by a server and the devices are connected to it.

Question 9

Pros of client server?

Answer 9

• Easier to keep track of files
• Easier to form backups
• Easier to update and install software
• Very reliable

Question 10

Cons of client servers?

Answer 10

• Expensive and need IT specialists to maintain it
• If servers go down all clients lose work
• May become overloaded if being accessed all at once

Question 11

Whats a p2p network?

Answer 11

All devices are equal commecting directly without a server

Question 12

Pros of P2p?

Answer 12

• easy to maintain
• No dependence on server (if one lost whole thing isn’t)

Question 13

Cons of p2p?

Answer 13

• Devices need updates and security done induvidually.
• Backups are complicated
• Slow down when other devices access them

Question 14

Whats a NIC?

Answer 14

Network interface controller is a peice of hardware that allows a device to connect to a network. Nowdays built in motherboard

Question 15

What are switches?

Answer 15

Connect devices to a LAN. switches receive data in frames from one device and transmit data to other devices with correct MAC addresss

Question 16

What are routers?

Answer 16

Responsible for transmiting data between nerworks. Always connected to 2 networks. Direct data in packets to destination

Question 17

Whats a WAP?

Answer 17

Needed to set up a device. And allows devices to connect wirelessly

Question 18

Whats a DNS?

Answer 18

Used to translate website domain names into IP addresses. Means you don’t need IP addresses to access a website

Question 19

What is hosting?

Answer 19

A business uses its server to store files on another organisation.

Question 20

Pros of the cloud?

Answer 20

• Can access files from any device
• Easy to increase how much storage is available
• No need to pay IT staff to manage hardware
• updated automatically

Question 21

Cons for the cloud?

Answer 21

• Need internet to access
• Stored in cloud which is vulnerable to hackers
• subscription fees and storage may be expensive

Question 22

What is a web server?

Answer 22

Where the WWW is hosted on.

Question 23

What is a star topology?

Answer 23

Where all the devices are connected to a centeral switch or server that controls the network.

Question 24

Pros of star topology?

Answer 24

• If one device fails or a cable is disconnected rest of the network is unnaffected
• simple to add more devices
• Better performance and less data collisions

Question 25

Cons of star topology?

Answer 25

- In a wired network everything needs to be connected to centeral server. Can be expensive - If problem with switch server whole network is affected

Question 26

Whats a mesh topology?

Answer 26

- where devices are connected directly or indirectly to each other without the need for a switch or server - Work by sending data along the fastest route

Question 27

Pros of mesh topology?

Answer 27

- No single point where a network can fail. If one device fails data is sent along another route

Question 28

Cons of mesh topology?

Answer 28

- Very expensive as you need a lot of wire

Question 29

How are wireless networks used to transmit data?

Answer 29

By radio waves

Question 30

Pros and cons of wireless networks?

Answer 30

- More convinient as you can move around while connected - Cheaper

Question 31

What is bluetooth?

Answer 31

- A connection between two devices so data can be shared - Normally 10m - Lower bandwith compared to Wifi - often used in mobile/handware devices

Question 32

What is Wifi?

Answer 32

- Can be used by multiple devices to connect LAN at the same time - connection between 40-100m - often used in homes

Question 33

What are ethernet cables?

Answer 33

Can use to connect devices on a LAN. and very fast and reliable

Question 34

What in encryption?

Answer 34

- when data is transfered into code which someone with a key can access - essential for sending data securely

Question 35

What is encrypted text called?

Answer 35

Cipher text

Question 36

What is non encrypted text called?

Answer 36

Plain text

Question 37

What does communication on the same networks use?

Answer 37

Mac addresses

Question 38

What do communications across different networks use?

Answer 38

Ip addresses

Question 39

Things about Mac addresses?

Answer 39

- Assigned to all network devices by the manufacturer - use 48 bit or 64 bit. To be converted to hexa decimal - Used by ethernet protocool

Question 40

Things about IP Adresses?

Answer 40

- Used when sending data between TCP/IP networks - assigned manually or automatically before the device accesses the network

Question 41

Things about IPV4?

Answer 41

Uses 32 bits Over 4 billion ip addresses Split into 8 bit chunks

Question 42

Things about ipv6?

Answer 42

- was created due to increasing amount of devices created - Over 2^128 addresses - split into 16 bit chunks

Question 43

What is a network standard?

Answer 43

Set of agreed requirements for hardware and software - Important as it allows their products be be able to be compatiable with other devices

Question 44

What is TCP/IP?

Answer 44

Dictates how data is sent between networks. Made up of TCP (set of rules how devices connect to network) Ip(directing packets to their destination across the network)

Question 45

Whats HTTP?

Answer 45

Hyper text transfer protocol Used by web browsers to access websites and communicate with web servers

Question 46

Whats HTTPS?

Answer 46

HTTP secure Encrypts all information sent and received Secure version of HTTP

Question 47

Whats FTP?

Answer 47

File transfer protocol Used to access files on a network

Question 48

Whats POP3?

Answer 48

Post office protocol Used to retrieve emails from a server . Only hold it until you download it.

Question 49

Whats IMAP3?

Answer 49

Internet message protocol Retrieves emails from a server. Hold it until you delete it. Used my most email providers

Question 50

Whats SMTP?

Answer 50

Simple mail transfer protocol Used to send emails Also used to transfer emails

Question 51

Whats a layer?

Answer 51

- Group of protocols with similar function

Question 52

What do layer do?

Answer 52

Services the layer above it

Question 53

Advantages of layers?

Answer 53

- Breaks network communication into manageable peices - helps them comcentrate on one layer - can be changed without affecting other layers