© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Computer Literacy for IC3

Unit 3: Living Online

Chapter 1:

Understanding the Internet

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America.

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Learning Outcomes

• Identify how traditional telephone systems work • Identify why the Internet was created • Identify how packets are labeled • Identify how packet switching works • Identify relationships between computers in a

Local Area Network• Identify how computers are connected

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Learning Outcomes (cont’d)

• Identify characteristics of a Wide Area Network • Identify types of cables and their characteristics • Identify how networks are connected to make

super networks • Identify the parts of an Internet address • Search online for available domain names • Identify the role of a domain name server

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Learning Outcomes (cont’d)

• Identify functions of computers on the Internet as hosts, gateways, and routers

• Identify the benefits and risks of networking • Identify the relationship between the Internet

and the World Wide Web • Identify the functions of a gateway and an

Internet Service Provider • Identify measurements used to describe

transmission rates

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Learning Outcomes (cont’d)

• Identify methods of connecting to the Internet via a telephone company

• Identify methods of connecting to the Internet via a cable television company

• Identify methods of connecting to the Internet via a wireless radio or satellite company

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Learning Outcomes (cont’d)

• Identify the organization that coordinates domain names

• Identify elements of the code of ethical conduct of system administrators

• Identify the characteristics of strong passwords • Identify the function of a firewall

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Traditional Phone Systems

• Circuit Switching• wires leading back to a

central office

• Star Configuration• Switchboard Operator

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

System to Survive Major Losses

• Advanced Research Projects Agency (ARPA)• Created by J.C.R. Licklider in 1962• Concept of a “Galactic Network”

• Advanced Research Projects Agency Network (ARPANET)• Network of Networks• Keep one path alive• Computer provided millions of instructions per second

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

TCP/IP – Transmission Control Protocol/Internet Protocol

• Data divided into small packets• Consisting of bits (b) and bytes (B)• Checksum – sum of numbers in packet

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Data Travels – Increased Survival

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

TCP/IP

• Protocol• Groups of rules used to manage data exchange

• File Transfer Protocol (FTP)• Enables users to transfer files between computers

• Telnet• Enables users to logon to remote computer

• E-mail (1972)

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Networks of Computers

• Local Area Network (LAN)• Small geographical connection of PCs to share files

and resources (printers, scanners, etc).• Each element is a node• Connected to a network server

• Peer-to-Peer network• Computers are connected directly to each other

without a server

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Servers on a Network

• File server – storing and retrieving files• Print server – coordinating use of a shared

printer• Web server – storing and providing Web pages• Database server – interpreting requests and

retrieving data from a database• Mail server – managing electronic mail

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Client – Server Relationship

• Client• A computer connected

to a server in a client/server network

• Server• A computer that

manages a network and all its devices

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Methods of Connections

• Infrared (IR) • Twisted pair• Coaxial cable• Wireless• Fiber optic cable

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Type Cost Distance Security Speed

Twisted Pair

Lowest <100 meters

Good Good

Coax Medium 100-500 meters

Good Good

Radio

(wireless)

Low Up to miles

Poor Fair

Infrared Low Short and line of sight

Excellent Excellent

Fiber optic

High Many miles

Excellent Excellent

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Network Wire Codes

• 10BASE-T• 10 – indicates speed = 10

MBPS• T – indicates twisted pair

• 10BASE-T4• 4 – indicates 4 twisted

pairs

• 1000BASE-T• 1000 MBPS

• 10Base-2 • (Thin Coax)

• 10Base-5 • (Thickwire Coax)

• 10Base-F• (Fiber)

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Wide Area Networks (WAN)

• Further apart than a hundred meters• Connections

• Twisted pair for short distances (inside buildings or small offices)

• Broadband coax, fiber optic, or radio for intermediate distances

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Connections Between Networks

• Bridge• Used to send and receive data when networks are

connected and use the same protocols

• Gateway• Used to send and receive data when networks are

connected and use different protocols

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Addresses on the Internet

• http://www.australia.gov.au

httpProtocol

govg (TLD)

Generic Top Level Domain

aucc (TLD)Country

Code Top Level

Domain

australiaDomain name

World Wide Web

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Role of Domain Name System

• Host• Internet Protocol (IP) address• Domain Name System (DNS)

• Domain Name Server

• Internet Corporation for Assigned Names and Numbers (ICANN)

• Registry• Internet Service Provider (ISP)

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Internet Backbone

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Birth of World Wide Web

• Browser• Mosaic• Netscape• Microsoft Internet Explorer• Mozilla Firefox• Apple’s Safari

• Hypertext Markup Language (HTML)• <b>hello<b> - the word hello bolded• Hyperlinks – www.weather.com

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Connecting to the Internet

• Internet Service Provider (ISP)• Modem

• Wired• Wireless

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Connections

• Dial-up Telephone Service• DSL Telephone Service• T1 Telephone Service• Cable Modem/Television

Service• ISP by Radio (Wireless)• Satellite

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Financing and Controlling

• Paying for Backbone Services• Increase in Usage

• Large Bandwidth for videos and pictures

• Caps on Data• Monthly caps• Cell phone usage

• Coordination of Domain Names (ICANN)

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Security and Ethics

• Usernames• Unique name on the

network• May be known, but should

not be shared

• Passwords• Easily remembered but not

easily guessed• Change periodically• Must be safeguarded

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Network Administrator’s Ethical Code

• Professional behavior

• Personal Integrity

• Privacy

• Laws and Policies • Communication

• System Integrity

• Education

• Responsibility

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

Firewall

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall.

QUESTIONS & ASSIGNMENTS