3.5 Computer Networks

Question 1

What is a computer network?

Answer 1

Two or more computers connected together

Question 2

Advantages of computer netoworks 4x

Answer 2

• share files
• share internet connection and hardware devices
• improved communication
• roaming profile
• central backup

Question 3

Disadvantages of computer networks 4x

Answer 3

• reliance on networked sources
• expensive hardware
• risk of spread of viruses
• specialist staff often required (maintenance & installation)

Question 4

What is PAN + examples

Answer 4

Personal Area Network
Connect electronic devices within a user’s immediate area
Wired or wireless
Mouse, keyboard, printer, headphones

Question 5

LAN

Answer 5

Local Area Network
Network contained within one building or site

Question 6

WAN

Answer 6

Wide Area Network
Computer network that extends over a large geographical area, connecting LANs

Question 7

LAN topologies

Answer 7

Star & bus

Question 8

Router

Answer 8

A network device that forwards data packets between computer networks

Question 9

Gateway

Answer 9

A device used to connect two different networks, especially a connection to the internet

Question 10

Internet

Answer 10

A global computer network of interconnected networks using standard communication protocols

Question 11

Broadband

Answer 11

A high speed internet connection

Question 12

Firewall

Answer 12

A network security system designed to prevent unauthorised access to or from a private network

Question 13

Define network protocol

Answer 13

A set of rules that allow devices and computer networks to communicate securely and transfer data reliably

Question 14

Ethernet network protocol

Answer 14

Data transmitted via wired LAN

Question 15

Copper cable vs fibre optic cable

Answer 15

F.O is faster using protons rather than electrons
Plus not a fire hazard

Question 16

Wi-Fi

Answer 16

=group of wireless network protocols
Using radio signals

Question 17

WAP

Answer 17

Wireless access point
Enables mobile devices to have wireless access to wired network

Question 18

TCP/UDP/IP

Answer 18

IP is an identifier of data
TCP/IP tgt to connect devices
UDP/IP tgt to route and transport data

Question 19

TCP VS UDP

Answer 19

TCP connect devices and labels packets
UDP sends packets

Question 20

FTP

Answer 20

file transfer protocol
Legacy communication to transfer files to another computer

Question 21

Email protocols

Answer 21

Both transfer electronic messages
SMTP: from client to servers or between servers
IMAP: only from an email server to client

Question 22

4 layer TCP/IP model

Answer 22

Application
Transport
Internet
Link

Question 23

differences between LAN and WAN

Answer 23

• LAN links only in one site
• speed of LAN transmission is higher than WAN with traffic
• WAN are typically public networks, LANs private, hence no need encryption

Question 24

define network protocol

Answer 24

a set of rules that allow computer networks to communicate securely and transfer data reliably

Question 25

what protocols are in application layer?

Answer 25

http https smtp imap

Question 26

what protocols are in transport layer?

Answer 26

tcp udp

Question 27

what protocols are in the internet layer?

Answer 27

ip

Question 28

what protocols are in link layer?

Answer 28

ethernet, WiFi

Question 29

network security measures

Answer 29

authentication encryption firewalls mac address filtering

Question 30

advantages of using wireless networks as opposed to wired networks

Answer 30

-lower setup costs -no wires/cables required -easy to connect new devices -can connect multiple devices without need for extra hardware

Question 31

advantages of using wired networks as opposed to wireless networks

Answer 31

-connection speeds usually faster -typically have higher bandwidth -fewer security risks

Question 32

disadvantages of using wireless networks as opposed to wired networks

Answer 32

-slower connection -connection not as stable -more security risks

Question 33

disadvantages of using wired networks as opposed to wired networks

Answer 33

-cables are hazardous and unaesthetic -expensive to set up -not all devices can connect via cables eg tablets

Question 34

how does authentication work?

Answer 34

takes one or more data specific to user and compare to stored credentials to compare if valid

Question 35

how does mac address filtering work?

Answer 35

takes unique MAC address for a device, and check if its in the whitelist and allow connection to network

Question 36

advantages of using a star topology instead of bus

Answer 36

- better security - a faulty connection only disables one computer

Question 37

why is HTTPS often used rather than HTTP?

Answer 37

S is secure can only be read by intended recipient

Question 38

what is encryption?

Answer 38

changing data so they cannot be read (except for those with decryption key) to prevent unauthorised people from reading sensitive data