1.3 Computer networks, connections and protocols

Question 1

Features of LAN networks

Answer 1

• Small geographical areas
• Connects multiple nodes
• Uses local connections such as Ethernet cables
• Private ownership
• Slightly faster
• Used for smaller businesses

Question 2

Features of WAN networks

Answer 2

• Multiple geographical areas
• Connects multiple LANs
• Uses wide area connections such as the cloud
• Private or public ownership
• Slightly slower
• Used for global or nationwide services

Question 3

Factors affecting the performance of a network

Answer 3

• Number of devices connected
• Bandwidth, the amount of data that can be carried through a connection at any one time
• Interference
• Network traffic
• Proximity to WAP
• Latency, the length of time information takes to travel through the network
• Error rate/collisions

Question 4

Switch

Answer 4

Connects a device on a LAN using MAC addresses

Question 5

Router

Answer 5

Connects devices on a WAN using IP addresses

Question 6

WAP

Answer 6

Connects wired networks to wireless devices using their MAC addresses

Question 7

NIC

Answer 7

Used to connect a device on the network. Each has an individual MAC address

Question 8

Transmission media

Answer 8

The way in which data is sent between connected devices e.g. copper cables

Question 9

Features of a client-server network

Answer 9

• A central server backs up all file servers
• Security is controlled by a central server
• All users are reliant on the central server
• Using servers enables businesses to grow to hundreds or thousands of computers and users

Question 10

Features of a Peer-to-Peer network

Answer 10

• Each computer needs to be backed up
• Security is controlled by each individual member
• There is no central sever
• If one computer goes down, only its services are lost
• Network is difficult to maintain beyond a few computers

Question 11

How does a DNS work?

Answer 11

• Client sends a DNS request for domain
• DNS checks for domain, the forwards it on to the next DNS till IP and name match on in their database
• Found IP returned to client
• Client requests webpage from web server with matching IP address

Question 12

Hosting

Answer 12

• Provides database servers
• Backup sites remotely
• More bandwidth
• Monitor servers 24/7

Question 13

The Cloud

Answer 13

• Services delivered over the internet
• Accessible by any internet connected computer

Question 14

Advantages of The Cloud

Answer 14

• Can be accessed easily
• Hosting organisations secure data well
• Hosting organisations can back up data in different servers
• Computing power is not required from the client to access stored data
• Simple to expand

Question 15

Disadvantages of The Cloud

Answer 15

• Slow for data needs to be requested and transferred over long distances and there is a lot of network traffic
• Subscription data storage can result in the loss of data accidentally
• Personal data not stored by personal database
• Limitations can be used by the service provider
• Loss of internet connection results in a loss of availability of stored data by the client

Question 16

Advantages of Star Network

Answer 16

• Fast data transfer to the hub as each wire isn’t shared with other computers/A signal doesn’t need to be transmitted to all computers on the network
• If on node/cable fails the other computers aren’t affected
• Easy to add a new node or device
• Fewer data collisions can occur

Question 17

Disadvantages of Star Network

Answer 17

• Requires additional hardware such as the central switch and network cables
• If the central switch fails the whole network goes down

Question 18

Advantages of Mesh Network

Answer 18

• No single point of failure, it is resilient
• Expansion and modification can be done without disrupting the network
• Data can be transmitted from different devices simultaneously

Question 19

Disadvantages of Mesh Network

Answer 19

• Can involve redundant connections
• Expensive to install cabling if using wired connections
• Network administration and maintenance is difficult

Question 20

Features of Ethernet

Answer 20

• Fast data transfer
• Better physical security
• High range
• Less susceptible to interference
• Physical limitations with portability
• Costly physical installations
• Safety hazards with physical cable

Question 21

Features of Wi-Fi

Answer 21

• Slower data transfer
• Less secure
• Range relies on WAP quality and interference
• Can move around within range
• Cheaper to set up and add new devices
• Compatible with most devices

Question 22

Features of Bluetooth

Answer 22

• Very slow data transfer
• Less secure
• Very short range
• Ideal for personal devices and ad-hoc connections
• Low power consumption

Question 23

Encryption

Answer 23

Used to protect data in case it is hacked or accessed illegally. Doesn’t prevent hacking however renders data incomprehensible without necessary decryption tools

Question 24

IP address

Answer 24

Changes, used for routing across WANs

Question 25

Standard

Answer 25

A set of technological specifications that allow devices made by different manufacturers to communicate with one another

Question 26

Protocol

Answer 26

A set of rules defining how devices communicate and transfer data on a network, ensuring all devices interpret data in the same way

Question 27

HyperText Transfer Protocol

Answer 27

Used for websites

Question 28

HyperText Transfer Protocol Secure

Answer 28

Used for websites and encrypts data to restrict access

Question 29

File Transfer Protocol

Answer 29

Delivers and receives files

Question 30

Transmission Control Protocol/Internet Protocol

Answer 30

Organises packet transfer down fastest route and reorders them, making sure that none have been lost and resending the message if so. Also routes packages over the internet

Question 31

Simple Message Transfer Protocol

Answer 31

Sends messages to the server then the internet

Question 32

Internet Message Access Protocol

Answer 32

Accessed messages from the server appear in your inbox without deleting it, so that it can be accessed by multiple recipients

Question 33

Post Office Protocol

Answer 33

Takes messages from the server and deletes them

Question 34

MAC address

Answer 34

Doesn't change, used for routing across LANs, assigned by NIC

Question 35

Features of MAC address

Answer 35

- Six numbers - 00-FF - Separated by : - 3B:14:E6:39:0A:2C

Question 36

Feature of IPv4

Answer 36

- Four numbers - 0-255 - Separate by . - 72.129.214.16

Question 37

Features of IPv6

Answer 37

- Eight numbers - 0000-FFFF - Separated by : - 1023:0ef1:0000:0000:34dd:00fe:0189:2233