1.3 Computer networks, connections and protocols

Question 1

2 types of networks

Answer 1

LAN (Local Area Network), WAN (Wide Area Network)

Question 2

3 features of LANs

Answer 2

Connected over a small geographical area located on a single site, hardware owned by the organisation using it, wired with UTP cable, fibre optic or wireless - Wi-Fi

Question 3

3 features of WANs

Answer 3

Connected over a large geographical area - connecting LANs together, connected with telephone lines, fibre optic cables or satelite links, expensive to set up

Question 4

5 factors that affect the performance of networks

Answer 4

Bandwidth, number of users, transmission media, error rate, latency (delay)

Question 5

Define client-server model

Answer 5

Have one or more central computers or servers that hold and manage recourses. A server controls access and security to one shared file store.

Question 6

3 advantages of client-server model

Answer 6

Easier to manage security files / take backups of all shared data / install software updates to all computers

Question 7

4 disadvantages of client-server model

Answer 7

Expensive to setup and maintain, requires special IT specialists to maintain, server is a single point of failure, security-cyber-attacks

Question 8

Define peer-to-peer model

Answer 8

Connects computers so that each computer shares all or part of its recourses. A peer is a computer on a network and is equal to all other peers.

Question 9

4 advantages of peer-to-peer model

Answer 9

Easy to maintain, specialist staff not required, no dependency on a single computer, cheaper - no expensive hardware required

Question 10

3 disadvantages of peer-to-peer model

Answer 10

Less secure, manage own backups / security, difficult to maintain a well-ordered file store - file duplication

Question 11

Wireless Access Point tasks

Answer 11

Allows wireless-enabled devices to access the network. It avoids the need to install cables, so it is more convenient.

Question 12

Routers tasks

Answer 12

Sends data between networks and is needed to connect a Local Area Network to a Wide Area Network. Can form a LAN by connecting devices within a building and makes it possible to connect different networks together.

Question 13

Switches tasks

Answer 13

Sends data between computers on a Local Area Network. They segment traffic by forwarding traffic to the correct location.

Question 14

NIC (Network Interface Controller/Card) tasks

Answer 14

Connects a device to a wired or wireless networking connection and uses a protocol to ensure successful communication.

Question 15

Transmission media

Answer 15

Carry data signals from one computer to another.

Question 16

DNS (Domain Name Server)’s role

Answer 16

A Domain Name Service is made up of multiple Domain Name Servers. Role in the conversion of a URL to an IP address.

Question 17

Define hosting

Answer 17

The storing of files and data on a web server. The web server is referred to as a host.

Question 18

The Cloud’s role

Answer 18

The cloud is servers that are used to store data and programs and can be accessed over The Internet.

Question 19

Webservers and Client’s role

Answer 19

Host websites and deal with client requests.

Question 20

3 star and mesh network topologies

Answer 20

Star network topology, full mesh network topology, partial mesh network topology

Question 21

Explain star network toplogy

Answer 21

All the devices connect into a central switch. The switch is intelligent and makes sure traffic only goes where it is intended.

Question 22

Explain full mesh network topology

Answer 22

Every device is connected to every device. The advantage is if you get a break in any of the connections you can still route your traffic via another route.

Question 23

Explain partial mesh network topology

Answer 23

In this network topology multiple routes exist between different devices. However, every device is not connected to every single other device - compromised solution.

Question 24

2 modes of connection

Answer 24

Wired - ethernet, wireless - bluetooth / Wi-Fi

Question 25

3 advantages of Wi-Fi

Answer 25

Move around freely, easier to set-up, less expensive than wired

Question 26

4 disadvantages of Wi-Fi

Answer 26

Speeds are slower than wired, relied on signal strength to the WAP, signal can be obstructed, less secure than wired

Question 27

What is the range, amount of bandwith / power that Wi-Fi takes?

Answer 27

Range of about 100m, high bandwidth, takes quite a lot of power

Question 28

What is the range, amount of bandwith / power that bluetooth takes?

Answer 28

Range of about 10m, low bandwidth, takes very little power

Question 29

Define encryption

Answer 29

The process of scrambling data so that it cannot be read without a translation key. Unencrypted messages are referred to as plaintext.
Encrypted messages are referred to as ciphertext.

Question 30

Function of IP (Internet Protocol) addressing

Answer 30

Used to route frames on a WAN (packets). Every device on the Internet has a unique IP which is assigned by a server.

Question 31

Function of MAC (Media Access Control) addressing

Answer 31

A unique serial number assigned to each network interface controller (NIC). It is used to route frames on a LAN.

Question 32

Define standard

Answer 32

A set of specifications for hardware/software. Enables products to be compatible with each other and interact with each other.

Question 33

Examples of standards

Answer 33

ASCII/Unicode, IEEE, HTML, PNG/GIF/MP3

Question 34

6 common protocols

Answer 34

TCP/IP, HTTP(S), FTP, POP, IMAP, SMTP

Question 35

Function of TCP/IP (Transmission Control Protocol/Internet Protocol)

Answer 35

Used to communicate over LANs and WANs.

Question 36

Function of HTTP(S) (Hypertext Transfer Protocol (Secure))

Answer 36

Used for webpage requests.

Question 37

Function of FTP (File Transfer Protocol)

Answer 37

Used for file transfers.

Question 38

Function of POP (Post Office Protocol)

Answer 38

Used for receiving email. Downloads email from the server to your device and deletes it from the server.

Question 39

Function of IMAP (Internet Message Access Protocol)

Answer 39

Used for receiving email. Keeps email on the server. Allows your device to stay in sync with the server.

Question 40

Function of SMTP (Simple Mail Transfer Protocol)

Answer 40

Transfers outgoing emails from one server to another / from an email client to a server.

Question 41

What is the concept of layers

Answer 41

To divide the complex task of networking into smaller, simpler tasks that work with each other. The hardware / software of each layer has a defined responsibility. Each layer provides a service to the layer above it.