Technology In Action Chapter 12 Review Database Electronic

Technology In Action Chapter 12 Advantages of Using Databases • Store and retrieve large quantities of information Recording grades Financial Aid • Data centralization • Data integrity Student Registration • Flexibility Student Information Student housing Database Parents © 2006 Prentice-Hall, Inc. NEXT SLIDE 2

Technology In Action Chapter 12 Database components • Field – Data type: text, numeric, date, object, hyperlink… • Record • Table – Primary key – Foreign key (referential integrity) © 2006 Prentice-Hall, Inc. 3

Technology In Action Chapter 12 Database Types • Relational database • Object-oriented database •

Technology In Action Chapter 12 Database Management Systems (DBMS) • Application software designed to acquire and analyze data • Microsoft Access, Oracle • Four main operations of a DBMS are: – – Creating databases and entering data Viewing and sorting data Extracting or querying data (SQL) Outputting data © 2006 Prentice-Hall, Inc. 5

Technology In Action Chapter 12 Managing Data: Information Systems • Office support systems (OSS) – Microsoft Office • Transaction processing system (TPS) • Management information system (MIS) • Decision support systems (DSS) © 2006 Prentice-Hall, Inc. 6

Technology In Action Chapter 12 & 13 Behind the Scenes: Networking and Security The

Technology In Action Chapter 12 Ch. 12 Topics • • • Advantages of a network Client/server and peer-to-peer networks Classifications of client/server networks Client/server network components Moving data in a client/server network Securing networks © 2006 Prentice-Hall, Inc. NEXT SLIDE 8

Technology In Action Chapter 12 Network • Definition (Ch. 7) • Advantages: – – – Increase productivity Enable the sharing of resources Facilitate Internet connectivity © 2006 Prentice-Hall, Inc. NEXT SLIDE 9

Technology In Action Chapter 12 Two architectures Peer-to-Peer Client/Server Every node communicates with every other node All nodes communicate through the server Used for fewer than 10 users Used for more than 10 users Not easily scalable Easily scalable Decentralized Centralized © 2006 Prentice-Hall, Inc. 10

Technology In Action Chapter 12 Client/Server Networks • Server based network: – Clients – Servers • Servers respond to requests from clients • Servers perform specific tasks • Scalable network © 2006 Prentice-Hall, Inc. NEXT SLIDE 11

Technology In Action Chapter 12 Classifications of Client/Server Networks • LAN: – Local area network • WAN: – Wide area network • MAN: – – Metropolitan area network Computers linked together within a city or county • PAN – Personal area network • Intranet © 2006 Prentice-Hall, Inc. NEXT SLIDE 12

Technology In Action Chapter 12 Constructing Client/Server Networks • • • Servers Network topologies Transmission media Network operating system (NOS) Network adapters Network navigation devices © 2006 Prentice-Hall, Inc. 13

Technology In Action Chapter 12 Servers • Number and type of servers depend on network size and workload • Dedicated server: – Perform one specific function • Examples: – – – Authentication server File server Printer server Database server Email server Web server © 2006 Prentice-Hall, Inc. 14

Technology In Action Chapter 12 Network Topologies • The physical layout of computers, transmission media, and other components • Types of network topologies include: – – – Bus topology Ring topology Star topology © 2006 Prentice-Hall, Inc. 15

Technology In Action Chapter 12 Bus Topology • All nodes are connected in sequence on a single cable • Used most often on peer -to-peer networks • Networked computers communicate with each other • One computer transmits data at a time: – Access methods avoid data collisions – Data is transmitted in “packets” © 2006 Prentice-Hall, Inc. 16

Technology In Action Chapter 12 Ring Topology • Nodes are laid out in a

Technology In Action Chapter 12 Star Topology • Nodes connect to a central communications device (hub/switch) • A node sends a signal to the hub which retransmits it to the other nodes • A node accepts the signal addressed to it © 2006 Prentice-Hall, Inc. 18

Technology In Action Chapter 12 Transmission Media • The routes data takes to flow between devices on a network: • Wired – Twisted pair cable – Coaxial cable – Fiber-optic cable • Wireless: – Wireless Fidelity (Wi-Fi) – Uses radio waves – 802. 11 standard © 2006 Prentice-Hall, Inc. 19

Technology In Action Chapter 12 Choosing a Cable • • • Maximum run length Bandwidth Bend radius Cable cost Installation costs Susceptibility to interference • Signal transmission methods © 2006 Prentice-Hall, Inc. 20

Technology In Action Chapter 12 Network Operating Systems (NOS) • Provide the protocol that controls the communication between devices on the network • Major network operating systems: – – – Windows Server 2003 UNIX Novell Net. Ware © 2006 Prentice-Hall, Inc. 21

Technology In Action Chapter 12 Network Adapters • Devices that enable computers to communicate on a network • Network interface cards (NICs): – – – Generate network transmission signals Create data packets Act as information gatekeepers Ethernet compliant Wireless NICs © 2006 Prentice-Hall, Inc. 22

Technology In Action Chapter 12 Network Navigation Devices • Media Access Control (MAC) address: – – – Six 2 -digit numbers (01: 40: 87: 44: 79: A 5) Physical address of network adapter Internal network identification • Repeaters and Hubs: – Amplify signals and retransmit them • Switches and Bridges: – Send data on a specific route through the network – Bridges send data between collision domains • Routers: – Send information between two networks © 2006 Prentice-Hall, Inc. 23

Technology In Action Chapter 12 Network Security • Authentication: – User ID and password used to access the network • Access privileges: – Enable access to certain network systems • Physical protection measures: – Restrict physical access to sensitive network equipment – Magnetic card readers – Biometric access devices © 2006 Prentice-Hall, Inc. NEXT SLIDE 24

Technology In Action Chapter 12 Network Security • Firewalls: – – Prevent access to the network by unauthorized users Composed of software and/or hardware Screens and validates data packets Bastion host/proxy server © 2006 Prentice-Hall, Inc. NEXT SLIDE 25

Technology In Action Chapter 12 Network Firewall Layout Firewall Perimeter Network Internal Network External Screening Router Bastion Host /Proxy Server Internal Screening Router © 2006 Prentice-Hall, Inc. 26

Technology In Action Chapter 12 Summary Questions • How does a client/server network differ from a peer-to-peer network? • What are the different classifications of client/server networks? • What components are needed to construct a client/server network? • What are the various network topologies? • What types of transmission media are used in client/server networks? © 2006 Prentice-Hall, Inc. NEXT SLIDE 27

Technology In Action Chapter 12 Ch. 13 Topics • • • Managing the Internet Interaction between Internet components IP addresses and domain names Data transmission and protocols HTML and XML E-mail and instant messaging © 2006 Prentice-Hall, Inc. NEXT SLIDE 28

Technology In Action Chapter 12 Management of the Internet Who owns the Internet? – – Individuals Universities Government agencies Private companies Who pays for the Internet? – – US taxpayers Businesses Universities Other countries Who manages the Internet? – Nonprofit organizations – User groups © 2006 Prentice-Hall, Inc. NEXT SLIDE 29

Technology In Action Chapter 12 Internet Networking • A network of networks: – Worldwide network of computer systems – Communications protocols • • • Network hierarchy T lines Network access points Points of Presence The network model © 2006 Prentice-Hall, Inc. NEXT SLIDE 30

Technology In Action Chapter 12 Network Hierarchy • Tier 1: – The Internet backbone – Moves large amounts of data – Provide access to Regional ISPs Tier 3 ISP Tier 2 ISP • Tier 2: – Regional ISPs – Provide access to local ISPs • Tier 3: – Local ISPs – Provide Internet access to homes and businesses © 2006 Prentice-Hall, Inc. 31

Technology In Action Chapter 12 T Lines • High speed fiber-optic lines • T-1 line: – 24 simultaneous voice or data channels – 1. 544 Mbps throughput • T-2 lines: – 4 T-1 lines – 6. 3 Mbps throughput • T-3 lines: – – 28 T-1 lines 44. 76 Mbps throughput • T-4 lines: – 168 T-1 lines – 247. 176 Mbps throughput © 2006 Prentice-Hall, Inc. 32

Technology In Action Chapter 12 Network Access Points (NAPs) • Points of connection between ISPs • Routers move data between networks Tier 1 ISP Routers Tier 2 ISPs © 2006 Prentice-Hall, Inc. Routers Tier 2 ISPs 33

Technology In Action Chapter 12 Points of Presence (POP) • Bank of modems where individual users connect to an ISP Other computers Your ISP Your computer © 2006 Prentice-Hall, Inc. Point of Presence 34

Technology In Action Chapter 12 Network Model • Internet communications follows the client/server network model • Clients request services • Servers respond to requests • Types of servers include: – Web servers: ü Host Web pages – Commerce servers: ü Enables the purchase of goods and services over the Internet – File servers: ü Provide remote storage space for files that users can download © 2006 Prentice-Hall, Inc. 35

Technology In Action Chapter 12 Animation: Network Model 4. Click to view animation. Click once only. Network Access Point (NAP) 2. Your request 1. goes Youtorequest your ISP’sa point of presence Web page. Your request goes to the National Backbone Network (POP). 5. Your request goes to the Web site’s server 3. Your request goes to a Network Access Point YOU ARE HERE © 2006 Prentice-Hall, Inc. ISP’s Point of Presence (POP). The Web page is sent back to you in packets. Web site’s server 36

Technology In Action Chapter 12 Data Transmission and Protocols • Computer protocols are rules for electronic information exchange • Open system protocols: – Any computer can communicate with other computers using the same protocols • • • Circuit switching Packet switching TCP/IP © 2006 Prentice-Hall, Inc. NEXT SLIDE 37

Technology In Action Chapter 12 Circuit Switching • Dedicated connection between two points • Remains active until the transmission is terminated • Telephone communications © 2006 Prentice-Hall, Inc. 38

Technology In Action Chapter 12 Packet Switching • Data is broken into small units called packets • Packets are sent over various routes to their destination • Packets are reassembled by the receiving computer • Packets contain: – – – Destination/source addresses Reassembling instructions Data © 2006 Prentice-Hall, Inc. 39

Technology In Action Chapter 12 Animation: Packet Switching ISP New York Web. Packets Page Data 01 02 03 04 05 06 07 08 09 10 11 12 Your ISP 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Click to view animation ISP Virginia ISP Florida © 2006 Prentice-Hall, Inc. Your Computer 40

Technology In Action Chapter 12 TCP/IP • Transmission Control Protocol (TCP): – Prepares data for transmission – Provides error checking – Enables resending lost data • Internet Protocol (IP): – Responsible for sending data from one computer to another © 2006 Prentice-Hall, Inc. 41

Technology In Action Chapter 12 IP Addresses • Unique number that identifies devices connected to the Internet • Typical IP address: – 197. 24. 72. 157 • Static address: – Address never changes • Dynamic address: – Temporary address • Dynamic Host Configuration Protocol (DHCP) © 2006 Prentice-Hall, Inc. NEXT SLIDE 42

Technology In Action Chapter 12 Domain Names • Name that takes the place of an IP address • Sample domain name: – www. mywebsite. com • Top level domains (TLD): – Portion of the domain name that follows the period (dot) – Sample top level domain names: ü. com; . org; . edu; and. net • Second-level domains: – Unique name within a top level domain – Sample second-level domain names: ü Yahoo. com; Google. com; and Unesco. org © 2006 Prentice-Hall, Inc. NEXT SLIDE 43

Technology In Action Chapter 12 Other Protocols • File Transfer Protocol (FTP): – File sharing protocol – Files are downloaded and uploaded using the Internet – ftp: //garbo. uwasa. fi • Telnet: – Protocol for connecting to a remote computer and a TCP/IP service – Enables a client computer to control a server computer © 2006 Prentice-Hall, Inc. NEXT SLIDE 44

Technology In Action Chapter 12 HTTP and SSL • Hypertext Transfer Protocol: – Protocol for transferring hypertext documents – Hypertext documents are linked to other documents ü Hyperlink • Secure Socket Layer: – – – Security protocols that protect sensitive information Encrypts data https: // © 2006 Prentice-Hall, Inc. NEXT SLIDE 45

Technology In Action Chapter 12 HTML • Hypertext Markup Language: – Format for creating Web pages – Not a programming language but a set of rules for marking up text HTML Web Page <h 1>This is the Heading</h 1> This is text using Arial font. This text is italicized. This text is bold. This text color is red This is a hyperlink <a href="http: //vig. prenhall. com/"> www. prenhall. com</a> © 2006 Prentice-Hall, Inc. NEXT SLIDE 46

Technology In Action Chapter 12 Common Gateway Interface (CGI) • Browsers request that a program file executes (runs) • Adds Web page interaction: – Adding names to guest books/mailing lists – Completing forms © 2006 Prentice-Hall, Inc. NEXT SLIDE 47

Technology In Action Chapter 12 Client-Side Application • A program that runs on a client computer with no interaction with the server • Types of client-side applications include: – HTML document embedded with Java. Script code – Applet: ü Small program that resides on the server © 2006 Prentice-Hall, Inc. NEXT SLIDE 48

Technology In Action Chapter 12 Extensible Markup Language (XML) • Designed for information exchange • Tools used to create your own markup language • Used in e-commerce transactions © 2006 Prentice-Hall, Inc. NEXT SLIDE 49

Technology In Action Chapter 12 Communications Over the Internet • E-mail: – Created in 1971 by Ray Tomlinson – Simple Mail Transfer Protocol (SMTP) – Multipurpose Internet Mail Extensions (MIME) ü Protocol for attaching files to e-mail • E-mail security: – Encryption: ü Private-key encryption ü Public-key encryption (128 -bit key) – Secure data transmission software ü Safe. Message © 2006 Prentice-Hall, Inc. NEXT SLIDE 50

Technology In Action Chapter 12 Instant Messaging (IM) • Client/server application program for realtime, text based conversations • Popular instant messaging programs: – – AOL Instant Messenger ICQ Yahoo! Messenger Windows Messenger © 2006 Prentice-Hall, Inc. NEXT SLIDE 51