Living OnlineUnit 9

Network Fundamentals

• Describe a network• Explain the benefits of a network• Identify risks in computing• Describe the roles of clients & servers• List & describe types of networks• List & describe communications media &

hardware• Describe network security

Objectives

2 or more connected devices Can transfer data

Network

Networks Benefits vs. Risks

Benefits Risks

Theft of services

Theft of Information

Hatred & vengeance

For the thrill of it

Why Hack?

T or F. Hackers invade other people’s computers only for fun.

T or F. Software sharing is one of the benefits of networking.

When you are on a network, you should assume that your email is not _____________?◦ Private

T or F. It is easier for a virus to spread on a network.

Review

Server manages & provides a service to client

Network OS Username & password

Network Types- Client-Server

No server Small office or house Easy to set up

Network Types- Peer to Peer

Local Area Network Small geographic area

◦ Office, school, house

WLAN◦ Wireless◦ Need Wi-Fi card

Network Types- LAN

Wide Area Network Large geographic

area◦ Two or more LANs

connected by routers◦ Big businesses with

office around country or world

Internet is biggest WAN

Connected by fiber, satellites, telephone

Network Types- WAN

Global network of connected, smaller networks

World Wide Web & email are most popular

Network Types- Internet

Web based for internal company use◦ Handbooks, manuals, employment forms, work

news, etc◦ Only can access from within that company◦ Through web browser

Network Types- Intranet

Similar to Intranet

Outside users with user name & password can have access to internal info

Network Types- Extranet

How is the network at school different than your home one? ◦ How is it the same?

Which type of network has an OS & requires a username/password for access?◦ Client-server

What are two popular Internet features?◦ Email & Web

At BK, you can access the Internet with your laptop & no wires. What type of network is this?◦ WLAN

Review

Dial-Up Modem (Int or Ext)

◦ Modulate-demodulate Converts analog to digital &

reverse

◦ Data over phone lines Dialed into a phone number

◦ SLOWWWWW Old- 300 bits per second (bps) or

baud rate Now- 56k or kilobits per second

Communication Hardware- Modem

Coaxial (Coax) cable

High speed, always on◦ Broadband◦ 20Mbps (Megabits per second)

Cable Modem

Comm. Hardware- Cable Modem

Digital Subscriber Line

High speed, always on◦ Broadband◦ Through phone lines◦ 3Mbps

Can use phone & Internet at same time◦ Filters on phones

Comm. Hardware- DSL Modem

ISDN (Old)◦ Faster than dial-up, over phone line

T1◦ High speed for business (1.5Mbps)◦ 24 copper or Fiber optic telephone line

FiOS◦ Similar to T1◦ Faster speeds◦ Limited areas

Comm. Hardware- Others

Router◦ Connects computers◦ Shares one Internet connection◦ May allows wireless access◦ Firewall

Wireless Adapters or NIC

Communication Hardware

How They Connect

T or F. A modem converts analog to digital signals.

T or F. Hackers invade other people’s computers only for fun.

A _______ is confined to a limited geographical area.

A _______ is made up of several local area networks.

A _______ is a simple device that connects multiple computers together.

Review

ISP◦ Internet Service Provider◦ Pay them (Comcast, Verizon)

Who to Connect to?

Dial-Up◦ Slow◦ Telephone Lines

Broadband◦ High Speed◦ Always On◦ Cable, DSL, Satellite

Cable, Phone, Dish/Air, Fiber Optics Wi-Fi

◦ Wireless access◦ Public (Starbucks)

ISP Services

Speeds

Control access to computer◦ User name, passwords◦ If none, unauthorized people can gain access &

take/read valuable info OR change it so no one can use it

Passwords◦ Change often◦ Use upper & lowercase letters, numbers, punctuation

Not easy stuff◦ Don’t write them down “cheat sheet”

Broken mostly by shared ones or cheat sheets, not guessing

Network Security Issues

Firewall◦ Protects against

unauthorized access to network from outside

Antivirus Software◦ Always be running,

updating

Wi-Fi Protection◦ Use the security settings

Network Security Issues

Be careful who you hire◦ People who don’t follow rules

Back up data off-site

Biometric security◦ Fingerprint reader◦ Voice pattern◦ Retina scan

Network Security Solutions

What device allows many PC’s to share a single, high-speed Internet connection?◦ Router

What are the companies called that charge you for Internet access?◦ ISP

What is the slowest Internet access method?◦ Dial-Up

Review

Living OnlineUnit 9

Network Fundamentals