Technology in Action Alan Evans Kendall Martin Mary Anne Poatsy Twelfth Edition

Technology in Action Chapter 13 Behind the Scenes: How the Internet Works

Inner Workings of the Internet The Management of the Internet Internet Networking, Data Transmission, and Protocols Internet Identity: IP Addresses and Domain Names Copyright © 2016 Pearson Education, Inc.13-2

The Management of the Internet Objective 1.Who owns, manages, and pays for the Internet? Copyright © 2016 Pearson Education, Inc. 13-3

Internet Networking, Data Transmission, and Protocols Objectives 2.How do the Internet’s networking components interact? 3.What data transmissions and protocols does the Internet use? Copyright © 2016 Pearson Education, Inc. 13-4

Internet Identity: IP Addresses and Domain Names Objective 4.Why are IP addresses and domain names important for Internet communications? Copyright © 2016 Pearson Education, Inc. 13-5

The Management of the Internet Copyright © 2016 Pearson Education, Inc.13-6

Internet Networking Internet Data Routes Copyright © 2016 Pearson Education, Inc.13-7 Main paths are known collectively as Internet backbone

Internet Networking Internet Data Routes Copyright © 2016 Pearson Education, Inc.13-8

Data Transmission and Protocols Network follows standard protocols to send information Protocol is a set of rules for exchanging electronic information They are the “rules of the road” for the information superhighway Copyright © 2016 Pearson Education, Inc.13-9

Data Transmission and Protocols Circuit Switching Not used to connect two computers  Inefficient when applied to computers  Computers transmit data in a group, or burst  Processor works on next task and ceases to communicate until ready to transmit next burst  Circuit would have to remain open, therefore unavailable to other systems, or have to be reestablished for each burst Copyright © 2016 Pearson Education, Inc.13-10

Data Transmission and Protocols Packet Switching Copyright © 2016 Pearson Education, Inc.13-11

Data Transmission and Protocols TCP/IP Protocol the Internet uses for transmitting data  Main suite of protocols is TCP/IP  Consists of many interrelated protocols Copyright © 2016 Pearson Education, Inc.13-12

Internet Identity: IP Addresses and Domain Names Each device connected to Internet required to have a unique number  Called the IP address Domain names are word-based IP addresses Copyright © 2016 Pearson Education, Inc.13-13

Internet Identity: IP Addresses and Domain Names How computer gets IP address (either/or)  Static IP address never changes Assigned by network administrator or ISP  Dynamic IP address is temporary Assigned from pool of addresses More common Copyright © 2016 Pearson Education, Inc.13-14

Internet Identity: IP Addresses and Domain Names Domain Names Copyright © 2016 Pearson Education, Inc.13-15

Coding and Communicating on the Internet HTML, XML, and Other Web Building Blocks Communications Over the Internet Copyright © 2016 Pearson Education, Inc.13-16

HTML, XML, and Other Web Building Blocks Objective 5.What web technologies are used to develop web applications? Copyright © 2016 Pearson Education, Inc

Communications Over the Internet Objective 6.How do and instant messaging work, and how is information using these technologies kept secure? Copyright © 2016 Pearson Education, Inc

HTML, XML, and Other Web Building Blocks HTML Not a programming language Set of rules for marking blocks of text Browser knows how to display text Surrounded by pairs of HTML tags Tags and text referred to as an element  This should be bolded and italicized. Copyright © 2016 Pearson Education, Inc.13-19

HTML, XML, and Other Web Building Blocks CSS Copyright © 2016 Pearson Education, Inc.13-20

XML is different from HTML  eXtensible Markup Language (XML) describes what data is  Users build markup languages to accommodate data formats and needs  Provides method of data validation through XML schema diagrams (XSD) JSON stands for JavaScript Object Notation HTML, XML, and Other Web Building Blocks XML and JSON Copyright © 2016 Pearson Education, Inc.13-21

HTML, XML, and Other Web Building Blocks Server-Side Applications Server-side applications  Web is a client/server network  Program on server is considered server-side  Can require many communication sessions between client and server  Can perform very complex operations Copyright © 2016 Pearson Education, Inc.13-22

HTML, XML, and Other Web Building Blocks Client-Side Applications Client-side applications  Programs that run on client computer  Require no interaction with web server  New data is only sent in response to a request  Exchange of data can make interactivity inefficient and slow  More efficient on local computer Copyright © 2016 Pearson Education, Inc.13-23

HTML, XML, and Other Web Building Blocks Client-Side Applications Copyright © 2016 Pearson Education, Inc.13-24

Communications Over the Internet Copyright © 2016 Pearson Education, Inc.13-25

Private-key encryption  Only the two parties have the code  Could be a shift code  Could be more complex substitution code  Main problem is key security Communications Over the Internet Security: Encryption Copyright © 2016 Pearson Education, Inc.13-26

Public-key encryption  Two keys (key pair) are created One for coding, one for decoding  Coding key is distributed as public key Message being sent is coded using public key  Decode using private key Only receiver knows private key  Mathematical relationship between two keys Communications Over the Internet Security: Encryption Copyright © 2016 Pearson Education, Inc.13-27

Communications Over the Internet Instant Messaging Copyright © 2016 Pearson Education, Inc.13-28

1.Who owns, manages, and pays for the Internet? 2.How do the Internet’s networking components interact? 3.What data transmissions and protocols does the Internet use? Check Your Understanding Copyright © 2016 Pearson Education, Inc.13-29

4.Why are IP addresses and domain names important for Internet communications? 5.What web technologies are used to develop web applications? 6.How do and instant messaging work, and how is information using these technologies kept secure? Check Your Understanding Copyright © 2016 Pearson Education, Inc.13-30

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. Copyright © 2016 Pearson Education, Inc.