© 2010 Pearson Education, Inc. | Publishing as Prentice Hall. Computer Literacy for IC 3 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 (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 CoaxMedium meters Good Radio (wireless) LowUp to miles PoorFair InfraredLowShort and line of sight Excellent Fiber optic HighMany miles Excellent

© 2010 Pearson Education, Inc. | Publishing as Prentice Hall. Network Wire Codes 10 BASE- T 10 – indicates speed = 10 MBPS T – indicates twisted pair 10BASE-T 4 4 – indicates 4 twisted pairs 1000 BASE-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 Protocol gov g (TLD) Generic Top Level Domain au cc (TLD) Country Code Top Level Domain australia Domain 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) hello - the word hello bolded Hyperlinks –

© 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