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Internet technologies

Internet technologies. 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 .

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Internet technologies

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  1. Internet technologies

  2. 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 E-Commerce: The Second Wave, Fifth Annual Edition

  3. Growth of the Internet E-Commerce: The Second Wave, Fifth Annual Edition

  4. Packet-Switched Networks • Local area network (LAN) • Network of computers located close together • Wide area networks (WANs) • Networks of computers connected over greater distances • Circuit • Combination of telephone lines and closed switches that connect them to each other E-Commerce: The Second Wave, Fifth Annual Edition

  5. LAN (Local Area Network) E-Commerce: The Second Wave, Fifth Annual Edition

  6. MAN (Metropolitan Area Network) E-Commerce: The Second Wave, Fifth Annual Edition

  7. WAN (Wide Area Network) E-Commerce: The Second Wave, Fifth Annual Edition

  8. Packet-Switched Networks (Continued) • Circuit switching • Centrally controlled, single-connection model • Packets • Files and e-mail messages on a packet-switched network that are broken down into small pieces • Travel from computer to computer along the interconnected networks until they reach their destinations E-Commerce: The Second Wave, Fifth Annual Edition

  9. E-Commerce: The Second Wave, Fifth Annual Edition

  10. Routing Packets • Routing computers • Computers that decide how best to forward packets • Routing algorithms • Rules contained in programs on router computers that determine the best path on which to send packet • Programs apply their routing algorithms to information they have stored in routing tables E-Commerce: The Second Wave, Fifth Annual Edition

  11. Router-based Architecture of the Internet E-Commerce: The Second Wave, Fifth Annual Edition

  12. Internet Protocols • Protocol • Collection of rules for formatting, ordering, and error-checking data sent across a network • Rules contributing to success of Internet • Independent networks should not require any internal changes to be connected to the network • Packets that do not arrive at their destinations must be retransmitted from their source network • Router computers act as receive-and-forward devices • No global control exists over the network E-Commerce: The Second Wave, Fifth Annual Edition

  13. TCP/IP • TCP • Controls disassembly of a message or a file into packets before transmission over Internet • Controls reassembly of packets into their original formats when they reach their destinations • IP • Specifies addressing details for each packet E-Commerce: The Second Wave, Fifth Annual Edition

  14. IP Addressing • Internet Protocol version 4 (IPv4) • Uses a 32-bit number to identify computers connected to the Internet • Base 2 (binary) number system • Used by computers to perform internal calculations • Subnetting • Use of reserved private IP addresses within LANs and WANs to provide additional address space E-Commerce: The Second Wave, Fifth Annual Edition

  15. IP Addressing (Continued) • Private IP addresses • Series of IP numbers not permitted on packets that travel on the Internet • Network Address Translation (NAT) device • Used in subnetting to convert private IP addresses into normal IP addresses • Internet Protocol version 6 (IPv6) • Protocol that will replace IPv4 • Uses a 128-bit number for addresses E-Commerce: The Second Wave, Fifth Annual Edition

  16. Domain Names • Sets of words assigned to specific IP addresses • Top-level domain (or TLD) • Rightmost part of a domain name • Internet Corporation for Assigned Names and Numbers (ICANN) • Responsible for managing domain names and coordinating them with IP address registrars E-Commerce: The Second Wave, Fifth Annual Edition

  17. Top-level Domain Names E-Commerce: The Second Wave, Fifth Annual Edition

  18. Domain Names E-Commerce: The Second Wave, Fifth Annual Edition

  19. Web Page Request and Delivery Protocols • Web client computers • Run software called Web client software or Web browser software • Web server computer • Runs software called Web server software • Client/server architecture • Combination of client computers running Web client software and server computers running Web server software E-Commerce: The Second Wave, Fifth Annual Edition

  20. Web Page Request and Delivery Protocols (Continued) • Hypertext Transfer Protocol (HTTP) • Set of rules for delivering Web page files over the Internet • Uniform Resource Locator (URL) • Combination of the protocol name and domain name • Allows user to locate a resource (the Web page) on another computer (the Web server) E-Commerce: The Second Wave, Fifth Annual Edition

  21. E-Commerce: The Second Wave, Fifth Annual Edition

  22. Electronic Mail Protocols • Electronic mail (e-mail) • Must also be formatted according to common set of rules • E-mail server • Computer devoted to handling e-mail • E-mail client software • Used to read and send e-mail • Example: Microsoft Outlook, Netscape Messenger E-Commerce: The Second Wave, Fifth Annual Edition

  23. Electronic Mail Protocols (Continued) • Simple Mail Transfer Protocol (SMTP) • Specifies format of a mail message • Post Office Protocol (POP) • POP message can tell the e-mail server to • Send mail to user’s computer and delete it from e-mail server • Send mail to user’s computer and not delete it • Simply ask whether new mail has arrived • Provides support for Multipurpose Internet Mail Extensions (MIME) E-Commerce: The Second Wave, Fifth Annual Edition

  24. E-Commerce: The Second Wave, Fifth Annual Edition

  25. Markup Languages and the Web • Text markup language • Specifies set of tags that are inserted into text • Standard Generalized Markup Language (SGML) • Older and complex text markup language • A meta language • World Wide Web Consortium (W3C) • Not-for-profit group that maintains standards for the Web E-Commerce: The Second Wave, Fifth Annual Edition

  26. Development of Markup Languages E-Commerce: The Second Wave, Fifth Annual Edition

  27. Hypertext Markup Language (HTML) • Prevalent markup language used to create documents on the Web today • HTML tags • Interpreted by Web browser and used by it to format the display of the text • HTML Links • Linear hyperlink structure • Hierarchical hyperlink structure E-Commerce: The Second Wave, Fifth Annual Edition

  28. Hypertext Markup Language (HTML) (Continued) • Scripting languages and style sheets • Most common scripting languages • JavaScript, JScript, Perl, and VBScript • Cascading Style Sheets (CSS) • Sets of instructions that give Web developers more control over the format of displayed pages • Style sheet • Usually stored in a separate file • Referenced using the HTML style tag E-Commerce: The Second Wave, Fifth Annual Edition

  29. Extensible Markup Language (XML) • Uses paired start and stop tags • Includes data management capabilities that HTML cannot provide • Differences between XML and HTML • XML is not a markup language with defined tags • XML tags do not specify how text appears on a Web page E-Commerce: The Second Wave, Fifth Annual Edition

  30. Processing a Request for an XML Page E-Commerce: The Second Wave, Fifth Annual Edition

  31. Intranets and Extranets • Intranet • Interconnected network that does not extend beyond organization that created it • Extranet • Intranet extended to include entities outside boundaries of organization • Connects companies with suppliers, business partners, or other authorized users E-Commerce: The Second Wave, Fifth Annual Edition

  32. Public and Private Networks • Public network • Any computer network or telecommunications network available to the public • Private network • A private, leased-line connection between two companies that physically connects their intranets • Leased line • A permanent telephone connection between two points E-Commerce: The Second Wave, Fifth Annual Edition

  33. Virtual Private Network (VPN) • Extranet that uses public networks and their protocols • IP tunneling • Effectively creates a private passageway through the public Internet • Encapsulation • Process used by VPN software • VPN software • Must be installed on the computers at both ends of the transmission E-Commerce: The Second Wave, Fifth Annual Edition

  34. 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 • Symmetric connections • Provide same bandwidth in both directions • Asymmetric connections • Provide different bandwidths for each direction E-Commerce: The Second Wave, Fifth Annual Edition

  35. Voice-Grade Telephone Connections • POTS, or plain old telephone service • Uses existing telephone lines and analog modem • Provide bandwidth between 28 and 56 Kbps • Digital Subscriber Line (DSL) • Connection methods do not use modem • Integrated Services Digital Network (ISDN) • Offers bandwidths between 128 Kbps and 256 Kbps E-Commerce: The Second Wave, Fifth Annual Edition

  36. Broadband Connections • Operate at speeds of greater than 200 Kbps • Asymmetric digital subscriber (ADSL) • Transmission bandwidth is from 100 to 640 Kbps upstream and from 1.5 to 9 Mbps downstream • Cable modems • Provide transmission speeds between 300 Kbps and 1 Mbps • DSL • Private line with no competing traffic E-Commerce: The Second Wave, Fifth Annual Edition

  37. Leased-Line Connections • DS0 (digital signal zero) • Telephone line designed to carry 1 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 E-Commerce: The Second Wave, Fifth Annual Edition

  38. Wireless Connections • Bluetooth • Designed for personal use over short distances • Low-bandwidth technology, with speeds of up to 722 Kbps • Networks are called personal area networks (PANs) or piconets • Consumes very little power • Devices can discover each other and exchange information automatically E-Commerce: The Second Wave, Fifth Annual Edition

  39. Wireless Ethernet (Wi-Fi or 802.11b) • Most common wireless connection technology for use on LANs • Wireless access point (WAP) • Device that transmits network packets between Wi-Fi-equipped computers and other devices • Has potential bandwidth of 11 Mbps and range of about 300 feet • Devices are capable of roaming E-Commerce: The Second Wave, Fifth Annual Edition

  40. Wireless Ethernet (Wi-Fi or 802.11b) (Continued) • 802.11a protocol • Capable of transmitting data at speeds up to 54 Mbps • 802.11g protocol • Has 54 Mbps speed of 802.11a • Compatible with 802.11b devices • 802.11n • Expected to offer speeds up to 320 Mbps E-Commerce: The Second Wave, Fifth Annual Edition

  41. Fixed-Point Wireless • One versionuses system of repeaters to forward radio signal from ISP to customers • Repeaters • Transmitter-receiver devices (transceivers) • Mesh Routing • Directly transmits Wi-Fi packets through hundreds, or even thousands, of short-range transceivers E-Commerce: The Second Wave, Fifth Annual Edition

  42. Cellular Telephone Networks • Third-generation (3G) cell phones • Combine latest technologies available today • Short message service (SMS) • Protocol used to send and receive short text messages • Mobile commerce (m-commerce) • Describes the kinds of resources people might want to access using wireless devices E-Commerce: The Second Wave, Fifth Annual Edition

  43. Internet2 and the Semantic Web • Internet2 • Experimental test bed for new networking technologies • Has achieved bandwidths of 10 Gbps and more on parts of its network • Used by universities to conduct large collaborative research projects E-Commerce: The Second Wave, Fifth Annual Edition

  44. Summary • TCP/IP • Protocol suite used to create and transport information packets across the Internet • POP, SMTP, and IMAP • Protocols that help manage e-mail • Languages derived from SGML • Hypertext Markup Language (HTML) • Extensible Markup Language (XML) E-Commerce: The Second Wave, Fifth Annual Edition

  45. Summary • Intranets • Private internal networks • Extranet • Used when companies want to collaborate with suppliers, partners, or customers • Internet2 • Experimental network built by a consortium of research universities and businesses E-Commerce: The Second Wave, Fifth Annual Edition

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