1.3.1 - Networks and Topologies

Question 1

Give the definition of a network

Answer 1

A group of interconnected computers or electronic devices for the purpose of communication.

Question 2

What are some advantages of networks?

Answer 2

They allow file sharing, hardware sharing, communication, levels of access, user monitoring, centralised security

Question 3

What are some disadvantages of networks?

Answer 3

Costly, susceptible to hacking, spread of malware and management requirements

Question 4

What does LAN stand for

Answer 4

Local Area Network

Question 5

What is a LAN

Answer 5

A network that is geographically confined to one building or site. It uses the builidng’s own infrastructure and cables to communicate

Examples of LANs are small businesses, homes and schools

Question 6

What does WAN stand for

Answer 6

Wide Area Network

Question 7

What is a WAN

Answer 7

A network that is spread over a large geographical area. It can be spread across the country or even the world

They use third party hardware and cabling to communicate e.g. satellites and the Internet

Question 8

What affects the speed of a network

Answer 8

• Number of devices
• Bandwidth
• Number of transmission errors

Question 9

What is Bandwidth

Answer 9

The amount of data that can be transferred over a set amount of time.

Businesses would have a higher bandwidth than homes as it has to be shared across more devices

Question 10

How does the number of devices on a network affect its performance

Answer 10

The more devices on a network, the higher chance there is of collisions due to transmission errors.
There are also more devices sharing the same bandwidth
This means it will take longer to transfer a message or data.
This reduces netowrk performance

Question 11

What does WAP stand for

Answer 11

Wireless access point

Question 12

What does the WAP do

Answer 12

WAP creates its own wireless network, which devices connect to. This increases the range of the wireless network.

The WAP then sends the wireless traffic it receives on to the main wired network.

Question 13

What do routers do

Answer 13

Sends data by the fastest route between networks and uses an IP address to direct network traffic internally. Also sends local data to the internet

Question 14

What does NIC stand for

Answer 14

Network interface controllers/cards

Question 15

What is a NIC and what are the different ways it can work?

Answer 15

A NIC provides a way of connecting to a network.

It can either be built in such as in PC’s or it can be a wireless NIC such as in phones or tablets

Question 16

What do switches do

Answer 16

Record which computers are connected to their corresponding ports.

It then uses the mac addresses to send data to a specific device

Question 17

What is transmission media?

Answer 17

They carry data signals from one computer to another. They are either wired cables such as copper and fibre optic or wireless such as Bluetooth

Question 18

What are two common models for connecting devices on a network?

Answer 18

• Client server networks
• Peer to peer networks

Question 19

How are servers and clients different in a server-client network model?

Answer 19

A server is able to manage and store files. They also control the network.

A client doesn’t store any data or control the network and it relies on the server for data.

Question 20

Advantages of a client server network

Answer 20

• Central storage of files - users can acces from any computer and single up to date versions of files - easier to keep track of files as they are edited
• Central management (unlike peer to peer) which allows for central security, backups and software
• Servers are dedicated machines left on all the time - data can always be accessed as it is never purposefully off

Question 21

Disadvantages of a client server network

Answer 21

• Costly - both in hardware requirements and as specialist employees needed
• Single server can only support a finite number of clients

Question 22

Advanatages of peer to peer networks

Answer 22

• Limited consequences if a device fails - no central server
• Cheaper hardware as servers are expensive
• Easy to add new devices - no specialist set up or maintenance

Question 23

Examples of server types

Answer 23

File servers, web servers, mail servers

Question 24

What is the Internet

Answer 24

A collection of interconnected computer networks. It isn’t the same thing as the World Wide Web as this is only a service the Internet hosts

Question 25

What network model does the internet use?

Answer 25

Mostly client-server

Question 26

What does Domain Name Servers do

Answer 26

Converts a human readable URL into an IP address

Question 27

Outline the steps in a DNS conversion

Answer 27

• Client computer sends a URL to the DNS and requests the corresponding IP
• DNS looks up the URL and finds the corresponding IP address on its index
• The IP address gets sent back to the client and then its browser requests it from the web server

Question 28

What does a DNS do if it can’t find the corresponding IP address?

Answer 28

It sends the URL to another DNS on the Domain Name Service

Question 29

What is a Domain Name Service?

Answer 29

It is a collection of multiple Domain Name Servers

Question 30

What is hosting?

Answer 30

Where a server stores files and data for client computers to request

Question 31

What is the cloud?

Answer 31

A remote storage place that is accessed through the internet and owned by a third party company

Question 32

Advantages of the cloud

Answer 32

• Reduces the need for manual backups as the data is backed up for the person
• You can access data from any device or location

Question 33

Disadvantages of the cloud

Answer 33

• Someone else could be accessing your data
• Security isn’t in your direct control so it may not be safe
• Can’t be accessed without an internet connection
• Transmission of data across the internet many not be secure and could be intercepted

Question 34

What is a network topology

Answer 34

The arrangement in which devices are connected on a network

Question 35

What is a star network topology

Answer 35

Where devices on a network are connected and can communicate with each other through a central switch.

They are used in home networks

Question 36

Advantages of star networks (3)

Answer 36

• New devices can be easily connected to the central switch
• Very reliable - A failure of one device doesn’t affect the whole network
• High performance as data gets sent to intended recipient only - avoids data collisions

Question 37

Disadvantages of star networks (2)

Answer 37

• If the switch fails, the whole network fails
• Very expensive as lots of cabling is required

Question 38

What is a mesh network topology?

Answer 38

Where there is no central connection point and instead, each device is connected to at least one other device

Question 39

Advantages of mesh networks (3)

Answer 39

• Highly robust - Messages can always get through as they have multiple routes to go
• New devices can be added easily
• Messages can be recieved more quickly as the route is more direct

Question 40

Disadvantages of mesh networks (2)

Answer 40

• Hard + expenisve to set up due to lots of connections
• Requires lots of maintenance

Question 41

Similarities of a switch and a router

Answer 41

• Both connect devices
• Both recieve data from the devices
• They both locate the destination for the data
• They both send the data to the intended recipient/location

Question 42

Differences between a switch and a router

Answer 42

• Switch uses MAC addresses
• Router uses IP addresses
• Routers connect networks together
• Switches connect devices (nodes)