Transcript Chapter 2
Chapter 2: Technology Infrastructure: The Internet and the World Wide Web The Internet and the World Wide Web Computer network Any technology that allows people to connect computers to each other The Internet A large system of interconnected computer networks spanning the globe World Wide Web A subset of computers on the Internet Growth … The Internet Internet Interconnected network of thousands of networks and millions of computers World Wide Web (WWW) Provides access to over one billion Web pages Key concepts Packet switching TCP/IP Client Server Computing The Internet: Key Technology Concepts Packet switching slices digital messages into packets sends packets along different communication paths reassembles packets once at their destination Routers Special-purpose computers that interconnect the computer networks that make up the Internet Routing algorithm Computer program that ensures packets take the best available path toward their destination The Internet: Key Technology Concepts Protocol A set of rules for formatting, ordering, compressing, and error checking messages TCP (Transmission Control Protocol) establishes the connections among sending and receiving Web computers, handles the assembly of packets at point of transmission, & reassembly at receiving end IP (Internet Protocol) provides the Internet’s addressing scheme IP Addresses Internet addresses expressed as 32-bit numbers appear as 201.61.186.227 -- each of the four numbers range from 0 to 255 allowing for up to 4 billion addresses In the next generation IP 128-bit addresses will allow about one quadtrillion addresses Domain Names A domain name is a set of words assigned to a specific IP address Internet Corporation for Assigned Names and Numbers (ICANN) Responsible for managing domain names and coordinating them with IP address registrars Client/Server Computing Client/server Computing model where powerful personal computers are connected together in a network with one or more servers. Client Powerful personal computer that is part of a network. Capable of displaying rich graphics, storing large files, and processing graphics and sound files. Server Networked computer dedicated to common functions needed by client machines -- storing files, software applications, utility programs, and printers. Internet I Network Architecture Internet NAPS and MAES ISP Service Level Choices Internet II Technology Environment A consortium of more than 180 universities, government agencies, and private businesses that are collaborating to find ways to make the Internet more efficient Goals Create a leading edge network capability for the national research community. Enable revolutionary Internet applications. Ensure the rapid transfer of new network services and applications to the broader Internet community. Next Generation Internet (NGI) initiated and sponsored by the federal government Focus: developing advanced applications and networking capabilities needed by government agencies Fiber Optics and Bandwidth Explosion replacing older transmission lines with fiber-optic cable improving fiber-optic-based communications technology & fiber-optic switching speeds Bandwidth Demand of Various Web Applications Wireless Web and 3G Technologies General Packet Radio Switching next generation technology carries data in packets, just like the Internet, but over radio frequencies that make wireless communications possible Wireless Application Protocol relatively new protocol -- supports virtually any wireless network and is supported by every operating system Wireless Markup Language programming language for devices using WAP Markup Languages and the Web Individual Exercise Search “XML Overview” using Google Click on the first reference: “XML Tutorial: Overview” Click on the first reference “HTML and XML” Browse through the presentation What are attributes of HTML? What are attributes of XML? How do they differ? What benefits does XML provide? Internet II and E-commerce: Emerging Features and Services IP Telephony Uses VOIP & Internet’s packet-switched network to transmit voice & other forms of audio communication Digital Libraries ASP distributes application software, multimedia, and other services on a fee basis by Distributed Storage ASPs can assist both in processing data, storing it, & dispersing it to multiple servers Internet II and E-commerce: Emerging Features and Services Distance Learning one the biggest education initiatives in recent years, provides courses and degree programs online Digital Video deliver better-than-broadcast quality video over the Internet on demand Video Teleconferencing significantly reduce the cost, workers share information that involves either and image or audio component Tele-immersion Merges virtual reality and video conferencing -- participants can see each other and collaborate on visual projects M-commerce Applications combines voice, data, images, audio, and video on one wireless device Exercise: For your group’s topic, “research” the topic and present a brief overview of the key issues concerning the topic that you found Distance Learning one the biggest education initiatives in recent years, provides courses and degree programs online Digital Video deliver betterthan-broadcast quality video over the Internet on demand Video Teleconferencing significantly reduce the cost, workers share information that involves either and image or audio component Tele-immersion Merges virtual reality and video conferencing -- participants can see each other and collaborate on visual projects M-commerce Applications combines voice, data, images, audio, and video on one wireless device