UNIT 4 Grade 8

Unit 4.1

Objective

• Explain what a network is

• Remember vocabs

• Explain PAN, LAN, WAN

• Understand core knowledge

Vocabulary

high bandwidth: high amount of data being transmitted

network switch: connect devices together on a network to form a wired network

data: raw facts and figures

servers: computers on a network that offers service to other devices

file server: offer devices a place to store and access file

computer network: a system that connects 2 or more computing devices for sending and recieving, sharing information (include PAN, LAN, WAN, MAN)

PAN (Personal area network): types of network where devices communicated over an small area

• weak, slow connection, limited range of communication, convenient & flexible, cost effective

LAN (Local area network): type of network where devices communicate over a small geographical area

• Have access within range (can only in access in the geographical area), for specific locations

• Fast & reliable, easy to set up & manage

• limited geographical coverage, high cost, limited mobility for wired device

WAN (Wide area network): type of network where devices communicate over larger geographical area

• enables communication in vast distances, provide access to remote recources and services, realtime collaboration in different locations

• higher cost of installation and maintenance, lower data transfer rate, need specialized language

wearable techonology: devices that could easily be worn on our body

Unit 4.2

Objective

• Explain what a network topology is

• Remember vocabs

• Understand core knowledge

Vocabulary

Network topology: a diagram that shows how device in a network are connected to one another and shows the network hardware (structure)

Bus topology: all the devices are joined to one cable (bus), terminator at the end of cable to absorb signals and stop them from being reflected down the bus

• Easy to install, cheap

• If the main cable fails/damage => whole networks stop working

• Larger network => data likely to be collided

• Devices on the network are visible to each other => security risk

Ring topology: each device is connected to 2 other devices forming a ring for the data to be passed around, data is travelled in 1 direction

• Data does not collide, flows 1 way, can be transferred quickly

• If the main cable is broken then the network in devices stop

Star topology: every device on the network has its own connection to the switch, main switch sends data packets to the destination device only

• Each device is connected seperately. dependable to other devices (will continue to work if a device or cable fails)

• Network performance is good - direct destination, easy to add new devices

• Expensive to install, if main switch is broken than other devices can’t be connected

Mesh topology: network structure where computers and devices are interconnected

• Network can be expanded without disruption

• redundant paths between devices, requires more cable => expensive, complicated implementation

Network architecture: How a network is designed

Node: single device in a network

Network hardware: dependable, fast hardware related for the use of networks (routers, NIC, wireless access point, network switch)

Router: connects diferent networks (provides access to the internet), connect LAN to the internet, router find the fastest route to send data

Network interface card (NIC): connects a computer to a computer network, has pre-programmed MAC address

Wireless access point (WAP): allows devices to connect to a network using Wifi

MAC address: number programmed into NIC and identify devices on a network

Unit 4.3

Objective

• Explain what a network is

• Remember vocabs

• Understand core knowledge

Vocabulary

Network switch: main device that allows devices to join together to form a network

Router: connect several LAN to form a WAN

Network interface card (NIC): allows any device that want to connect a network, contains MAC address

MAC Address: able to indentify you on a network

Wireless Access Point (WAP): network device that allows wireless devices to connect to the network using wifi

Ethernet cable: designed to work with ethernet parts on a NIC, helps for higher speeding

Server: basically computers that have anything: when you send someting you have to go to the server

File sever: offers a device a place to store and access files

Print server: take printing jobs: order to print

Mail server: store email messages to log in, send and recieve messages

Web server: provide internet accesibility to files and transmit files over the www.

Firewall: a security software that acts as a barrier to unauthorised access network traffic, check for security risks.

Pictures

Sub unit

Objective

• Explain what a protocol is

• Remember vocabs

• Understand core knowledge

Vocabulary

Protocol: an agreed set of rules that computers follow to communicate to each other over a network

Transmission Control Protocol / Internet Protocol (TCP/IP): routes data between devices and ensures it reaches intended destination

Hypertext Transfer Protocol (HTTP): Transfers website content (“hypertext”), these are set of rules for communicating with web servers => no S so websites that doesn’t have this isn’t secure

Hypertext Transfer Protocol Secure (HTTPS): Transfers website content (“hypertext”), these are set of rules for communicating with web servers with added encryption to improve security => websites that have this is secure

Data packet: small unit of data that is packaged to be sent across the network

IP address: unique number assigned to a computer on a network

Sender IP address: need to include this on the network to know where to forward the packet to

Recipient (Receiver) IP address: in case of a dropped packet, reciever address can request the package to be sent again

Packet number: needs to be included so the receiving (receipient) device can reassemble the packets in the correct order, helps receiving device know which packet is missing

Packet switching: the process of splitting data in smaller units

Pictures

Scalable considerations

Vocabulary

Electrical spikes/power surges: more voltage comes though the electrical wire to an device

• Faulty wiring or lightning strikes often cause binary bits to be flip between 0 and 1 => error in data transmission

Interference: occurs when many electrical devices are used in a small area

• Electrical & radio waves disrupt each other’s signals => errors in binary data, devices to disconnect from the network

Security breaches: unauthorized access to computer data, caused by malware or hackers

Hardware failure: a switch or other hardware fails => errors in dservers

Keeping it all secure

Vocabulary

dataset: collection of data (stored in a table)

Firewall: examines the incoming and outgoing of a network traffic to see if it violate rules or suspicious activity is blocked

User access control: network manager allowing some users such as administator to access the datasets

Password policies: creating strong passwords by following the policies given. Such as:

• Have at least 8 characters

• Password must contain letters, numbers, or symbols

Brute-force attack: an unauthorised access to the computer system by using a large dictionary to try multiple password combinations

Two-factor authentication: requiring two types of method in signing in, often by password and email verification/code from a 2nd device

Biometric security: uses people’s physical appearance to sign in (Ex. facial recognition, fingerprints)

Encryption: convert (information or data) into a cipher or code, especially to prevent unauthorized access. Uses secure protocols like (HTTP or HTTPS

Plaintext: data that has not been encrypted, can be intercepted

INTERFACES

command line interface

natural & speech recognition

graphical user interface: icons, menus, pointers basically graphics