Networks

Question 1

What is a network?

Answer 1

An arrangement of computers and other devices connected together to share resources and data

Question 2

What does LAN stand for?

Answer 2

local area network

Question 3

What are 3 characteristics of LAN?

Answer 3

• A network that covers a relatively small geographical area
• owned by the organization that uses it
• managed by a local manager or a team on that site

Question 4

Give 3 examples of where LAN is used

Answer 4

1) Home
2) Hospital
3) Factory

Question 5

What does WLAN stand for?

Answer 5

wireless local area network

Question 6

What is WLAN?

Answer 6

like a LAN but wireless, all connects to a router

Question 7

What does WAN stand for?

Answer 7

wide area network

Question 8

What are 3 characteristics WAN?

Answer 8

• it covers a wide geographical area by connecting two or more LANs
• computers in a WAN can connect with computers and users in other locations
• managed by several different people or parts of an organization working together

Question 9

What is the largest WAN?

Answer 9

the internet

Question 10

What is a client-server network?

Answer 10

A network that has at least one server to provide services to the client computers

Question 11

What is are 3 characteristics of a peer-to-peer network?

Answer 11

• doesn’t have a centralized server
• all computers are equal and communicate with each other directly without having to go through a server
• each user can give other users access to their computer and their programs and to any other device connected to them

Question 12

What is a network topology?

Answer 12

how the devices on a network are connected to each other

Question 13

What is a BUS TOPOLOGY?

Answer 13

A bus network consists of a single cable which each workstation is connected

Question 14

Name 2 advantages of bus topology

Answer 14

1) cheap to install and set up

2) easy to add new devices

Question 15

Name 2 disadvantages of bus topology

Answer 15

1) if the main cable fails, the whole network will fail

2) lots of data collisions if two or more devices transmit at the same time (lower data transmission speeds)

Question 16

What is a RING TOPOLOGY?

Answer 16

Cable connects one network device to connect another in a closed ring

Question 17

Name 2 advantages of ring topology

Answer 17

1) no collisions because of the use of the token system

2) data transmission is simple as data only travels in one direction

Question 18

Name 2 disadvantages of ring topology

Answer 18

1) slow transmission speeds, as data must pass through each computer before arriving to the destination
2) if the cable breaks then there will be no data transmission

Question 19

What is a STAR TOPOLOGY?

Answer 19

each workstation is connected to a central point

Question 20

Name 2 advantages of star topology

Answer 20

1) A damaged cable will not stop the whole network

2) Easy to locate faults

Question 21

Name 2 disadvantages of star topology

Answer 21

1) If the hub fails, the whole network fails

2) Expensive to install

Question 22

What are 2 advantages of connecting computer to form a network?

Answer 22

• The users can share resources

- files can be shared along a network allowing users to work collaboratively

Question 23

What are the benefits of a peer-to-peer network on a small company?

Answer 23

• expensive server and network operating systems are not required, so it is cheaper
• specialist staff are not needed to administer and maintain the network, so it is a lot cheaper
• requires less specialist knowledge to set up

Question 24

What are the benefits of a client-server network on a large company?

Answer 24

• all data can be saved on a file server, so it can all be backed up at the same time without having to back up the data on each computer seperately
• network security is stronger as access to file servers are controlled using logins and passwords

Question 25

What is the range of frequencies commonly used for data transmissions in wireless networks?

Answer 25

2.4-5 GHz

Question 26

What is meant by a channel?

Answer 26

each frequency range is divided into separate channels

Question 27

What is bandwidth?

Answer 27

Amount of data that can be transmitted per second (measured in bps)

Question 28

What is the bandwidth of a cable network?

Answer 28

10 Gbps

Question 29

What is the bandwidth of a wireless network?

Answer 29

600 Mbps

Question 30

What is the role of network interface controllers in connecting devices to computer networks?

Answer 30

- formats data so that it can be transmitted and received across a network - NICs are often built on chips on the computer motherboard

Question 31

What does the MAC address do?

Answer 31

ensures that data is directed to the correct computer

Question 32

What are hubs and switches used for?

Answer 32

-used to link computers so that they can communicate with each other once they have connected to the network using the NIC

Question 33

What do routers do?

Answer 33

- connect different networks together - read address information and forward the messages to the correct network - transfers data between home network and the internet

Question 34

Why are switches better than hubs?

Answer 34

- switches read the destination addresses of the messages and relay them to only the intended recipient - this reduces network traffic

Question 35

Why is data split into packets?

Answer 35

Data is split into packets so that higher bandwidth isn't needed for larger files

Question 36

What are 3 components that a packet consists of?

Answer 36

- header - body - footer

Question 37

What does the header component do?

Answer 37

- contain the source and destination address | - checks how many packets the data has been split into

Question 38

What does the body component do?

Answer 38

contains some of the data of a file

Question 39

What does the footer component do?

Answer 39

the footer informs the receiving device that this is the end of the packet

Question 40

What is a checksum?

Answer 40

an error detection technique

Question 41

What is flow control?

Answer 41

allowing the receiving computer to tell the sending computer to slow down transmission, so the receiving computer has time to process the received data

Question 42

How are devices connected on a wireless network?

Answer 42

- radio waves connect devices on a wireless network - each device has an adapter that sends and receives radio signals - a router broadcasts a signal that devices can detect and 'tune' into.

Question 43

what are 4 fields in a network packet

Answer 43

- source - destination - sequence number - packet length