Chapter 2 Technology Infrastructure The Internet and the World Wide Web

1. Chapter 2Technology InfrastructureThe Internet and the World Wide Web

2. The Internet and the World Wide Web • HTTP Servers(Hypertext Transfer Protocol) • Web Browsers (Internet Explorer, Netscape Navigator, Firefox)) • Web Pages with • hyperlinks TELNET FTP E-MAIL THE INTERNET USENET WWW

3. Growth the World Wide Web

4. World Wide Web Components • Packet Switching/Routing • Networks (LANS & WANS) • TCP/IP Communications Protocol • Client/Server Computing • Web Pages

5. Internet Backbone – U.S. Source: http://www.accd.edu/sac/lrc/john/wwwtest2.htm

6. Internet Backbone - Global

7. Routing Demo www.visualroute.com http://pages.ebay.com.cn/welcome/index.html

8. Internet Connectivity

9. Application Layer SSL (Secure Sockets Layer) Transport Layer Network Layer TCP/IP Protocol • The TCP/IP protocol controls assembly & disassembly of a file into packets for transmission over the Internet HTTP, FTP, Telnet, DNS,SMTP TCP Network Data Packets IP 101001 1101001 101101

10. Packet-Switching Networks • Digital data are sliced into packets, and sent over network on different paths then reassembled at their destination. • Routers: special purpose computers that interconnect computer networks and route packets to their ultimate destination • Routers use routing algorithms to ensure packets take the best available path

12. IP Addressing Internet Protocol Version 4 (IPv4) • A 32-bit number to identify computers connected to the Internet Sample IP Address: 168.212.226.204

13. TCP/IP Application Suite HTTP FTP Web Pages File Transfer

14. TCP/IP Application Suite SMTP TELENET E-Mail Terminal Emulation

15. ICANN ICANN is responsible for the global coordination of the Internet's system of unique identifiers such as domain names and addresses

16. Domain Names • A Domain Name is a set of words assigned to a specific IP address. • Protocol Name + Domain Name or IP Address = Uniform Resource Locator (URL). ftp://www.pcwebopedia.com/stuff.exe http://www.pcwebopedia.com/index.htmlhttp://143.166.83.38 http://www.secondleveldomain.topleveldomain

17. Domain Names • Unrestricted(e.g.,.com. .net, .org) • Restricted(.edu, .gov, .mil) • Country(e.g., .us, .cc, .tv) • New Domain Names (e.g.,.aero, .biz, .coop, .info, .jobs, .mobi, .museum, .name, .pro, .travel) • Vanity Domain names (e.g., .tv)

18. Domain Nameshttp://www.iana.org/gtld/gtld.htm

19. County Code Domain Nameshttp://www.iana.org/root-whois/index.html

20. Accredited Registrieshttp://www.icann.org/registrars/accredited-list.html

21. Domain Naming Issues • 2-63 Characters (A-Z, 0-9, “-”) • No “-” at Beginning or End • Brand Names & Cybersquatting • Dot-Com is Most Respected • Not Case Sensitive • Typically Represents a Business, or Product or Service Name, + Other Uses • About Registration & Name Ownership http://www.oreillynet.com/onlamp/blog/2005/06/the_worlds_longest_domain_name.html

22. Client-Server Computing • Web Client Computer • Runs software called Web client software or Web Browser software • Web Server Computer • Runs software called Web server software

23. Domain Name System (DNS) The Domain Name System (DNS) associates Domain Names with IP Addresses. Functionally, it’s a Web Page Phone Book. DNS IP Addresses URL is Resolved to IP Address www.abc.com 168.212.226.204 abc.com Home Page Hosting Server IP Address 168.212.226.204 Web Pages

24. Whois Search Whois is used to determine who the URL is registered to.

25. Electronic Mail Protocols • SMTP (Simple Mail Transfer Protocol) - specifies the format of a mail message • POP (Post Office Protocol) – used to retrieve e-mail from a server. • MIME (Multipurpose Internet Mail Extensions) – provides Support for graphics, audio & video content.

26. W3C The World Wide Web Consortium (W3C) is an international consortium that develops protocols and guidelines for the Web.

28. Standard Generalized Markup Language (SGML) • Offers a system of marking up documents that is independent of any software application. • Used to Create Other Markup Languages.

29. Hypertext Markup Language (HTML) • Prevalent markup language used to create Web pages • HTML tags are interpreted by a Web browser and are used by it to format the display of the text • HTML links can be structured as: • Linear hyperlink structures • Hierarchical hyperlink structures

31. Extensible Markup Language (XML) • It includes data management capabilities that HTML cannot provide • XML, HTML & XHTML: • XML does not have pre-defined tags. • XML tags do not specify how text appears on a Web page. • XHTML is a markup language written in XML that has a stricter syntax than HTML.

33. Other Web Page Functionality • Scripting Languages: JavaScript, JScript, Perl, and VBScript. • Cascading Style Sheets (CSS): Provide pre-defined Web page formatting.

34. Intranets and Extranets • Intranet • Interconnected network that does not extend beyond the organization that created it • Extranet • Intranet extended to include entities outside the boundaries of an organization • Connects companies with suppliers, business partners, or other authorized users

35. Networks • Public network • A network available to the public. • Private network • A private, leased-line connection between two companies that physically connects their intranets.

36. Virtual Private Network (VPN) • VPN • An extranet that uses public networks and their protocols • VPN software must be installed on the computers at both ends of the transmission

38. Internet Connection Options • Bandwidth • Amount of data that can travel through a communication line per unit of time • Net bandwidth • Actual speed that information travels

39. Voice-Grade Telephone Connections • POTS, or plain old telephone service • Uses existing telephone lines and an analog modem • Provides bandwidth between 28 and 56 Kbps • Digital Subscriber Line (DSL) • Connection methods that do not use a modem • Integrated Services Digital Network (ISDN) • Bandwidths between 128 Kbps and 256 Kbps

40. Broadband Deployment Broadband defined as greater than 200 Kbps • Asymmetric digital subscriber line (ADSL) • Cable Modem • Fixed Point Wireless Broadband • DSL • Satellite

41. Leased-Line Connections • DS0 (digital signal zero) • Telephone line designed to carry one digital signal • T1 line (also called a DS1) • Carries 24 DS0 lines and operates at 1.544 Mbps • Fractional T1 • Provides service speeds of 128 Kbps and upward in 128-Kbps increments • T3service (also called DS3) • Offers 44.736 Mbps

42. Wireless ConnectionsBluetooth • Designed for personal use (Personal Area Networks) over short distances (Up to 100 meters) • Speeds of up to 722 Kbps • Devices can discover each other and exchange information automatically

43. Wireless Ethernet (Wi-Fi – Wireless LANs) Protocols based on IEEE 802.11 Standard

44. Mobile Networks • Cellular - Third-generation (3G) Technology Cell Phones • Mobile commerce (m-commerce)

45. Internet 2 • Internet2 or UCAID (University Corporation for Advanced Internet Development) – A nonprofit consortium of universities and corporations which is developing an advanced, high-speed network for education and research. • Not to be confused with Web 2.0 - which is the unofficial “social networking & collaborative” Web.

46. Social Networking (Web 2.0) • Wikipedia, Blogs, RSS Feeds, Facebook, YouTube • Nearly 2 in 5 U.S. Internet Users Watched a YouTube Video in September 2007. • Nearly 70 million people viewed more than 2.5 billion videos on YouTube.com. • More than 38 million people viewed approximately 360 million videos on MySpace.com Source: comScore Video Metrix

47. Wikipedia http://www.wikipedia.org/

48. Blogs

49. RSS Feeds

50. RSS Feeds