1.3: COMPUTER NETWORKS, CONNECTIONS AND PROTOCOLS

Question 1

what is a LAN?

what are the characteristics of a LAN? (2)

Answer 1

• local area network
• geographically confined to a small/ limited area
• internal cabling (owned by organisation)

Question 2

what is a WAN?

what are the characteristics of a WAN? (2)

Answer 2

• wide area network
• geographically spread over a wide area
• 3rd party cabling/ infrastructure

Question 3

4 main factors affecting network performance: (and additional 3 ones)

Answer 3

Number of people accessing the network at the same time.​

Interference from other electrical devices eg; home mobile/ phones, wires/cables.​

Distance – data will take longer to travel over longer distances.​

Speed of the Network - bandwidth of the transmission medium

network latency
the number of transmission errors

Question 4

what is bandwidth?

Answer 4

amount of data that the medium can transfer over a given period of time

Question 5

how does more devices being connected to a network affect network performance?

Answer 5

bandwidth has to be distributed over more devices, thereby reducing the rate at which data can be sent to any particular device.

Question 6

what is latency?

Answer 6

latency is a measure of how long it takes a message to travel from one device to another across a network

Question 7

what are transmission errors?

Answer 7

when signals collide with each other and the transmission fails.

Question 8

when does a network collision occur?

Answer 8

when two devices on a network try to communicate simultaneously along the same communication channel.

Question 9

how does the number of devices correlate to the performance of a network in relation to collisions?

Answer 9

The greater the number of devices on a network, the more chance of a collision occurring, and the longer it takes to transmit a message.

Question 10

differences in a client server and a P2P in relation to ‘number of people and cost’: (2)

Answer 10

client server:
large network with large number of users (expensive)
P2P:
small network with small number of users (cheap as no server nor network technicians)

Question 11

differences in a client server and a P2P in relation to ‘where data is stored’: (2)
-for client-server networks, what does this enable the users to do?

Answer 11

client server:
-all files stored centrally so users can access files from any computer
P2P:
-files stored on singular computer/ spread across many computers

Question 12

differences in a client server and a P2P in relation to ‘how backups are completed’: (2)

Answer 12

client server:
-backups are all central. no need for individual backups
P2P:
-may need to perform own backups

Question 13

differences in a client server and a P2P in relation to ‘how security of files is undertaken’: (2)

Answer 13

client server:
central security// does not need to install protection on all individual computers

p2p:
security may need to be installed on individual computers

Question 14

what is the purpose of a wireless access point? (2)

Answer 14

• allows for wireless devices to connect to a network

- boosts signal on a LAN

Question 15

what does a NIC provide/ allow a device to do? (2)

Answer 15

a method of connecting to a network

-allows data packets to travel to and from a computer

Question 16

what is the purpose of a switch? (2)

Answer 16

• allows multiple devices to connect together

- directs packets to their destination on the network

Question 17

what is the purpose of a router? (2)

Answer 17

• directs packages/ data in a network to their destinations

- designates private IP addresses to network nodes

Question 18

how do routers work? (2)

Answer 18

• by collecting knowledge of available routes to transmit data.
• then determine the most suitable route for sending data.

Question 19

what is a server?

Answer 19

a powerful computer which manages access to a centralised resource or service

Question 20

what is the internet?

Answer 20

a worldwide collection of computer networks.

Question 21

what does the term ‘internet’ refer to? and what does it not refer to?

Answer 21

the network infrastructure, not the content stored on it.

Question 22

what is the purpose of the internet?

Answer 22

to enable communication on an international scale

Question 23

what is hosting?

Answer 23

the storing of files and data on a web server

Question 24

what is a web server referred to as?

Answer 24

a host

Question 25

what does a URL stand for?

what does the URL of a website include?

Answer 25

uniform resource locator

the host name

Question 26

what does a dns server have?

Answer 26

database of IP addresses

Question 27

what happens when you type in a URL address? (in relation to a dns) (2)
-what happens after this process?

Answer 27

• DNS looks up the domain name and returns its equivalent IP Address to the router
• which then can request/send data to correct destination.​

-user’s request is then forwarded to the server that resides at that network address.

Question 28

what happens if a dns server does not have a doman name’s address? what happens if nothing is found?

Answer 28

• it will check another DNS/ a higher DNS and update/add the address to itself once found​.
• if not found, user will receive an error 404 message

Question 29

why is a dns beneficial? why?

Answer 29

Advantage = DNS is beneficial for people as people do not have to remember IP addresses
-because it is easier to remember a URL.​

Question 30

what is a network?

-what is its purpose?

Answer 30

two or more computers (or devices) that are connected together for the purpose of communication