1.3 Network Connections and Protocols

Question 1

LAN (Local Area Network)

Answer 1

• A computer network over a small geographical area
• such as an office or a school.

Question 2

WAN (Wide Area Network)

Answer 2

• A computer network over a large geographical area.
• WANs are usually made up of interconnected LANs.

Question 3

Wi-Fi (wireless Ethernet)

Answer 3

Allows devices to connect to a LAN wirelessly (uses high frequency radio).

Question 4

Wi-Fi frequency –

Answer 4

different channels run on different frequencies.

Question 5

Client-server network -

Answer 5

• Has a powerful central server which provides resources (such as files),
• a login system
• software updates to clients connected to the network.
• Clients request services, the server responds.

Question 6

Peer-to-peer network

Answer 6

• Computers are all at the same level and connected to each other. - There is no central server.

Question 7

Network topologies:

Answer 7

A network topology is the physical layout of the network (when viewed from above).

Question 8

Mesh topology

Answer 8

All devices (nodes) connected to all other devices (nodes)

Question 9

Star topology -

Answer 9

Uses a central switch, with all devices (nodes) connected to the central switch.

Question 10

Wireless Access Points (WAPs) –

Answer 10

allow wireless (Wi-Fi) connections to a LAN.

Question 11

Routers –

Answer 11

allow Internet connection (forwards data packets onto the Internet) and can be used to create WANs

Question 12

Switches –

Answer 12

connect devices over a LAN (using MAC addresses to get the data across the Local Area Network).

Question 13

Network Interface Controller/Card (NIC) –

Answer 13

• a piece of hardware inside each computer that allows it to connect to a LAN.
• NICs contain the MAC address.

Question 14

Transmission media –

Answer 14

Cat-5 (Ethernet cables) and fibre-optic cables.

Question 15

Domain Name System (DNS) -

Answer 15

DNS converts human-readable domain names (such as google.com) into computer-readable IP addresses (such as 243.6.83.5)

Question 16

Web hosting -

Answer 16

• Paying a company (such as GoDaddy) to store your website online.
• They store your HTML files on their servers and allow people to view your website using their web browsers.

Question 17

The cloud

Answer 17

• simply another word for “online” storage (remote storage).
• Usually you would pay a company to store your data.

Question 18

Cloud computing

Answer 18

using software that is being run on a remote computer (usually pay a monthly subscription to use it).

Question 19

A Virtual Private Network (VPN) -

Answer 19

• Appears to network users like they are connected to a physical LAN or WAN without needing to be anywhere near the physical part of the network.
• They need to login with a username and password.
• Once logged in, they can access files, folders and software as though they were physically in the same building as the network.

Question 20

Ethernet -

Answer 20

• A protocol and set of standards for communicating over a Local Area Network.
• The Ethernet protocol controls how data is sent and received across a Local Area Network as well as the connectors and cabling.

Question 21

HTTP (Hyper Text Transfer Protocol) -

Answer 21

HTTP allows web browsers to request websites from web servers (this runs on port 80).

Question 22

HTTPS (Hyper Text Transfer Protocol Secure) -

Answer 22

HTTPS is the secure (encrypted) version of HTTP, suitable for exchanging sensitive information, e.g. bank details.

Question 23

FTP (File Transfer Protocol) -

Answer 23

• FTP allows large files and folders to be transferred across the Internet.
• Website developers might use this to upload their HTML files to be hosted on a web server.

Question 24

POP (Post Office Protocol) -

Answer 24

Allows users to download an email once only.
- When it has been downloaded, it is removed from the email server.

Question 25

IMAP (Internet Message Access Protocol) -

Answer 25

This is a modern email protocol that allows users to view their emails on the email server and download as many emails as they want on multiple devices.

Question 26

SMTP (Simple Mail Transfer Protocol) -

Answer 26

- used for sending emails and for transferring emails from one email server to another. - For example, it will send an email from Hotmail’s email server to Gmail’s email server

Question 27

Packet switching -

Answer 27

data is sent as individual chunks (data packets) that are routed through a network.

Question 28

Data packets –

Answer 28

chunks of data with an IP address, routed across a network.

Question 29

Network layers - TCP/IP model

Answer 29

The TCP/IP four-layer model is a something that network engineers use to understand and troubleshoot network problems.

Question 30

Factors affecting the performance of networks:

Answer 30

- Number of devices connected - bandwidth - latency