Chapter 4-networks

Question 1

What is a network

Answer 1

A network is 2 or more computers connected together to exchange data via cables or wireless signals

Question 2

What do networks allow

Answer 2

-resource sharing
-send messages
-share files between computers

Question 3

What’re modems

Answer 3

Modulators and demodulators

Question 4

What do modems do

Answer 4

Converts (modulates) a computers digital signal into an analogue signal for transmission over a telephone line
Demodulators turn analogue to digital to enable computers to process data
- used to allow computers to connect to networks over long distances

Question 5

What’s a hub

Answer 5

A hardware device that has multiple devices or computers connected to them to form a LAN

Question 6

What’s the function of hubs

Answer 6

Take data packet received at one of its ports and broadcast it to every computer in the network
-connect many devices or computers together to form a LAN

Question 7

What’s a disadvantage of hubs

Answer 7

They aren’t very secure or efficient

Question 8

What’s the difference between switches and hubs

Answer 8

Switches are more efficient in distributing data packets as they check data package and work out its destination address and sends data to appropriate computers ONLY which makes them much more secure

Question 9

What’s a bridge

Answer 9

Device than connects 1 lan to another lan that use the same protocol (communication rules)

Question 10

What’re bridges used for

Answer 10

To connect different parts of a lan so they can function together as a single lan

Question 11

What do routers do

Answer 11

Enable data packets to be routed between difference networks (join a lan to a wan)
Usuallly have internet cables and other cables which connect it to other computers or lans

Question 12

Describe the routing of data packets

Answer 12

Data is carried according to which protocol is used and usuallly contains information like the sender and receivers IP address which allows router to route a packet across a network to its correct destination to reassemble data in correct order at the receiving station

Question 13

What’s a gateway

Answer 13

A network point that acts as an entrance to other networks. It’s a key point that data passes through on its way to form other networks.

Question 14

What’s a network interface card (NIC)

Answer 14

-chip needed to allow devices to connect to a network and are usually parts of thee device hardware and contain a MAC (media access control) address generated in manufacturing

Question 15

What do NIC cards contain

Answer 15

Media access control address

Question 16

What’re the advantages of network cables over WiFi

Answer 16

-faster data transfer rates
-more secure
-better security

Question 17

What’re the 3 key info pieces that data packets contain

Answer 17

-header to identify the data packet
-sender and receivers IP address
-number of data packets which make up the whole messsage

Question 18

What do hubs and switches both do

Answer 18

Connnect computers together to form a LAN

Question 19

Why are switches more secure than hubs

Answer 19

Switches send specific data packets to specific computers in the lan using MAC address but are more expensive while hubs send data packets to all the networks which can cause traffic and poor security

Question 20

Discuss the advantages and disadvantages of using computer networks (6)

Answer 20

The advantages age is using a computer network is that it’s easier to share files and data as well as resources like printers can be shared with many computers at once,however this can result in longer printer ques. Since all the computers are connected there’s a greater risk of hackers and viruses spreading which could lead to a disabled network,in this case 1 computer will not be able to work alone. The cost of equipment like cables and routers could be expensive.furthermore the network allows central data storage which means files can be accessed from any work station, central settings can also be applied to restrict changing settings.

Question 21

Compare and contrast the uses of a router and switch

Answer 21

Router is used to connect LAN to form a WAN and also to the internet.routers transfer data between networks using ip addresses to direct information on while switches direct data packets using the MAC adress.switch connnects computers together to create a lan,each workstation connected to the network will have its own mac adress which the router learns then sends specific data packets to each workstation.

Question 22

Bluetooth and WiFi can connect devices together,discuss the advantages and disadvantages of using Bluetooth of WiFi

Answer 22

Bluetooth is more useful when transferring data between 2 devices whereas WiFi is more suitable for a full scale network. Devices connected with Bluetooth need to be in close proximity while the wifi devices have a larger range.less data is transferred by Bluetooth since it uses a lower bandwidth which causes slower data transfer speeds in comparison to WiFi. WiFi has better security than Bluetooth however Bluetooth is cheaper than WiFi. Both WiFi and Bluetooth use wireless technology which eliminates the need of cables, this reduces costs and tripping hazards.bluetooth is more energy efficient than WiFi .

Question 23

Describe the differences between common network environments (LAN,WAM,WLAN)

Answer 23

Local area networks cover a smalller geographical area which is normally limited to one building whereas wide area networks cover larger areas as they are LANs connected with a router. Connections between LANs could be either cabled or satellite while wireless local area networks use only wireless signals to connect devices via access points which are wired.

Question 24

Explain the term hacking using examples

Answer 24

Hacking is the unauthorized access to computer systems with the intentions of causing harm. Hackers can edit delete and steal your data as well as introduce viruses to cause disruption to a network.hackers could also be employed to expose weaknesses of the system.

Question 25

Use examples to describe differences between weak and strong passwords

Answer 25

A weak password is easy to guess and includes a few characters and consists of all letters or all digits. It typicallly relates to a user, for example their first name.a strong password is very difficult to guess to ensure maximum security. It consists of many letters (upper and lower case) and a variety of characters and numbers.

Question 26

Describe alternate methods of authentication other than user id and password that banks could use

Answer 26

If a bank only uses passwords as their authentication method then there’s a higher risk of hacking since passwords can be easily guessed or hacked by key logging softwares. Passwords can be generated so instead of that,customers could be asked a personal questions linked to their account to identify themselves such as selecting an image. Biometric data is also a good alternative since it’s unique to each individual and is impossible to copy which makes it a more secure option. Additionally the bank could request a TAN (transaction authentication number) or two factor authentication which add an extra level of security.