Puc IU


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Đây là chiếc loa mang tính di động siêu nhỏ gọn cho âm thanh vòm 360 độ trung thực, với hình dáng quả táo độc đáo, loa có thể xoay và mở thêm không gian tạo tiếng bass siêu trầm. Loa có 5 màu để lựa chọn và tự động đổi màu đèn LED khi nghe nhạc.
Giá : 170.000đ Tặng adaptor charge trị giá 20.000đ
Bảo hành 03 tháng
Màu sắc : 5 màu
* Tích hợp pin sạc, thời gian sử dụng pin lâu đén 6 - 8h
* Thiết kế thích hợp Điện thoại di động, MP3,MP4, Laptop, PSP, PDA ...

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Puc IU

  1. 1. Advanced Diploma of Information Technology MIT Nguyễn Hữu Phát Kent International College 80 hours
  2. 2. In this chapter, you will learn about:  The origin, growth, and current structure of the Internet  How packet-switched networks are combined to form the Internet  How Internet protocols and Internet addressing work  The history and use of markup languages on the Web, including SGML, HTML, and XML E-Commerce: The Second Wave, Fifth Annual Edition 3
  3. 3.  How HTML tags and links work on the World Wide Web  The differences among internets, intranets, and extranets  Options for connecting to the Internet, including cost and bandwidth factors  About Internet2 and the Semantic Web E-Commerce: The Second Wave, Fifth Annual Edition 4
  4. 4.  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 5
  5. 5.  Early 1960s › U.S. Department of Defense funded research to explore creating a worldwide network  In1969, Defense Department researchers › Connected four computers into network called ARPANET  Throughout 1970s and 1980s › Academic researchers connected to ARPANET and contributed to its technological developments E-Commerce: The Second Wave, Fifth Annual Edition 6
  6. 6.  1972 › E-mail was born  Mailing list › E-mail address that forwards any message received to any user who has subscribed to the list  Usenet › Started by group of students and programmers at Duke University and the University of North Carolina E-Commerce: The Second Wave, Fifth Annual Edition 7
  7. 7.  In 1991, NSF › Eased restrictions on commercial Internet activity › Began implementing plans to privatize the Internet  Network access points (NAPs) › Basis of new structure Internet  Network access providers › Sell Internet access rights directly to larger customers and indirectly to smaller firms and individuals through ISPs E-Commerce: The Second Wave, Fifth Annual Edition 8
  8. 8. http://www.internetworldstats.com
  9. 9. E-Commerce: The Second Wave, Fifth Annual Edition 10
  10. 10. The $23.4 billion in annual internet advertising spending exceeded advertising on cable TV for the first time (which was $21.4 billion), and took the No. 3 spot behind national and local TV ads ($29.8 billion) and newspaper ads ($34.4 billion).
  11. 11. Internet advertising is almost twice as large as broadcast TV advertising was in its 14th year ($13.3 billion) and nearly four times as large as cable TV ($6.5 billion).
  12. 12.  The Web › Software that runs on computers connected to the Internet  Vannevar Bush › Speculated that engineers would eventually build a memory extension device (the Memex)  In the 1960s › Ted Nelson described a similar system called hypertext
  13. 13.  Tim Berners-Lee › Developed code for hypertext server program  Hypertext server › Stores files written in hypertext markup language › Lets other computers connect to it and read files  Hypertext Markup Language (HTML) › Includes set of codes (or tags) attached to text
  14. 14.  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
  15. 15.  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
  16. 16.  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
  17. 17. E-Commerce: The Second Wave, Fifth Annual Edition 18
  18. 18.  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
  19. 19.  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 20
  20. 20.  Internet Protocol version 4/6 (IPv4/6) › 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 21
  21. 21.  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
  22. 22.  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
  23. 23. E-Commerce: The Second Wave, Fifth Annual Edition 24
  24. 24.  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
  25. 25.  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)
  26. 26.  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
  27. 27.  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)
  28. 28.  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
  29. 29.  Offers a system of marking up documents that is independent of any software application  Nonproprietary and platform independent  Offers user-defined tags  Costly to set up and maintain
  30. 30.  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 35
  31. 31.  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 36
  32. 32.  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 37
  33. 33. E-Commerce: The Second Wave, Fifth Annual Edition 38
  34. 34.  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
  35. 35.  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
  36. 36.  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
  37. 37.  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
  38. 38.  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
  39. 39.  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 44
  40. 40.  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  T3 service (also called DS3) › Offers 44.736 Mbps
  41. 41.  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
  42. 42.  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 47
  43. 43.  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 48
  44. 44.  One version uses 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
  45. 45.  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
  46. 46.  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 51
  47. 47.  Semantic Web › Project by Tim Berners-Lee › If successful  Would result in words on Web pages being tagged (using XML) with their meanings  Resource description framework (RDF) › Set of standards for XML syntax  Ontology › Set of standards that defines relationships among RDF standards and specific XML tags
  48. 48.  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 53
  49. 49.  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 54