1.3.3. Networks

Question 1

What is a network?

Answer 1

2 or more computers connected together, that transmit data

Question 2

What is a physical topology?

Answer 2

the physical layout of the network

Question 3

What is logical topology?

Answer 3

the topology that describes the flow of data through a network

Question 4

What is a bus topology?

Answer 4

topology where all terminals are connected to a backbone cable

Question 5

What are 2 advantages of the bus topology?

Answer 5

• cheaper to set up - does not require any additional hardware

Question 6

What are 3 disadvantages of the bus topology?

Answer 6

• if backbone cable fails, the entire network is diconnected - as traffic increases, performance decreases - all computer can see data transmission

Question 7

What is a star topology?

Answer 7

a network where a central node directs the flow of data, and each terminal is connected to the central node

Question 8

What are 3 advantages of the star toplogoy?

Answer 8

• no data collisions - if one cable fails, only that station is affected - data is transmitted faster

Question 9

What are 2 disadvantages of the star topology?

Answer 9

• expensive due to switch and cabling - if the central switch fails, the entire network fails

Question 10

What is a mesh topology?

Answer 10

a toplogoy where every node is connected to every other node, most commonly found with wireless technology

Question 11

What are 3 advantages of mesh topology?

Answer 11

• no cabling cost - as the numer of nodes increases, reliability and speed increase - data travels faster as it does not travel through a central switch

Question 12

What are 2 disadvantages of the mesh topology?

Answer 12

• need to purchse devices with wireless capabilities - maintaining the network is difficult

Question 13

What are protocols?

Answer 13

a set of rules defining how 2 devices communicate with eachother

Question 14

Why are protocols standard?

Answer 14

so devices from different manufacturers dont have problems communicating

Question 15

What is the structure of the internet?

Answer 15

the internet is a global network of interconnected networks

Question 16

What does TCP stand for?

Answer 16

transmission control protocol

Question 17

What does IP stand for?

Answer 17

internet protocol

Question 18

What is the function of the application layer during data transmission?

Answer 18

the application layer specifies what protocols need to be used, to relate the application to what it is being used for

Question 19

What is the 2 roles of the transport layer during data transmission?

Answer 19

• to establish an end-to-end connection between the source and destination computer - to split up data into packets

Question 20

What is the role of the network layer during data transmission?

Answer 20

adds the source and destination IP addresses

Question 21

What is the function of the link layer during packet transmission?

Answer 21

adds the MAC addresses to the packet

Question 22

What does the application layer do when it recieves data?

Answer 22

presents data in the form it was sent

Question 23

What does the transport layer do when it recieves data?

Answer 23

removes the port number and reassembles the packets

Question 24

What does the network layer do when it recieves data?

Answer 24

removes the IP adresses

Question 25

What does the link layer do when it recieves data?

Answer 25

removes the MAC address

Question 26

What is a local area network?

Answer 26

a network spread over a small geographical area or positioned on a single site

Question 27

What is a wide area network?

Answer 27

a network spread over a large geographical area, usually requiring extra hardware

Question 28

What does DNS stand for?

Answer 28

domain name system

Question 29

What is DNS?

Answer 29

the name given to the method of naming internet resources (.com, .co.uk etc)

Question 30

What is circuit switching?

Answer 30

the process of creating a direct link between 2 devices and data is transferred the entire duration of the link

Question 31

What is a requirement of circuit switching?

Answer 31

the transfer and download rates must be identical on both devices

Question 32

What is packet switching?

Answer 32

a method of communicating packets of data across a network

Question 33

What are 2 advantages of packet switching?

Answer 33

- there are mulitple methods to arrive at a destination, so if one breaks you can take another route - packets can be transferred over a very large network, such as the internet

Question 34

What is a disadvantage of packet switching?

Answer 34

time is spent deconstructing and reconstrucing packets

Question 35

What are 2 advantages of circuit switching?

Answer 35

- data arrives in a logical order, which results in a quicker reconstruction of data - it enables 2 users to hold a call without any delay in speech

Question 36

What are 2 disadvantages of circuit switching?

Answer 36

- devices must download and transfer at the same rate - switches introduce electrical interference, which can corrupt or destroy data

Question 37

What 4 things does the header of a data packet contain?

Answer 37

1. the source and destination IP address 2. protocols being used 3. order of the packets 4. the time to live limit

Question 38

What does the packet payload contain?

Answer 38

the raw data

Question 39

What does the packet trailer contain?

Answer 39

the checksum or cyclic reduncdancy check

Question 40

What is the purpose of a firewall?

Answer 40

to prevent unauthorised access to a network

Question 41

What 2 things is a firewall made up of?

Answer 41

- 2 network interface cards - firewall sofware

Question 42

What is a proxy?

Answer 42

a web server that acts as an intermediary, collecting and sending data on behalf of a user, protecting their identity

Question 43

What are 3 advantages of using a proxy?

Answer 43

- allows users to remain anonymous - data can be cached, making it faster to load - reduces web traffic

Question 44

What is the function of a network interface card?

Answer 44

to connect a computer to a network

Question 45

What is the function of a switch?

Answer 45

to direct the flow of data across a network, commonly used in star topologies

Question 46

What is the function of a router?

Answer 46

to connect 2 networks together

Question 47

What is the function of a gateway?

Answer 47

to connect 2 networks and translate protocols, so they can communicate without any issues

Question 48

What is client-server networking? (2 things)

Answer 48

- a relationship between terminals (computer) and a single server, - which allows them to communicate and share resources

Question 49

What are 3 advantage of client-server networking?

Answer 49

- increased security - central single backups - data and resources can be shared

Question 50

What are 2 disadvantages of client-server networking?

Answer 50

- expensive to set up - trained staff are required to maintain the network

Question 51

What is peer-to-peer networking?

Answer 51

a network where the terminals are all connected to each other to share resources

Question 52

What are 3 advantages of peer-to-peer networks?

Answer 52

- cheaper to set up - easy to maintain - easy to share resources

Question 53

What are 2 disadvantages of peer-to-peer networks?

Answer 53

- they can be used to contribute towards piracy - each computer has to be backed up independently