Chapter3 E-Commerce Technology Foundation

1、Chapter 3E-Commerce Technology Foundation . menu section1 section2 section3section4Chapter 33.1 The Conception and Composition of Internet 3.2 Typical Internet Service 3.3 TCP/IP 3.4 Application and Management of Domain Name . menu section1 section2 section3section43.1 The Conception and Composition

2、 of Internet3.1.1 The Origin and Development of Internet1The Origin of InternetThe precursor to the Internet, ARPAnet was a large wide-area network created by the United States Defense Advanced Research Project Agency. Its first two nodes that formed the ARPAnet were UCLA and Stanford Research Insti

3、tute, thereafter followed shortly by the University of Utah. . menu section1 section2 section3section43.1.1 The Origin and Development of Internet2The First Leap of InternetNSFnet is a wide area network developed under the auspices of the National Science Foundation. NSFnet replaced ARPAnet as the m

4、ain government network linking universities and research facilities. . menu section1 section2 section3section43.1.1 The Origin and Development of Internet2The First Leap of InternetIn 1995, however, the NSF dismantled NSFnet and replaced it with a commercial Internet backbone. the NSF implemented a

5、new backbone called Very-high-speed Backbone Network Service, which serves as a testing ground for the next generation of Internet technologies. . menu section1 section2 section3section43.1.1 The Origin and Development of Internet 3The Second Leap of InternetIn 1991, US firms began using Internet fo

6、r commerce, therefore Internet began to develop. Public access started in September 1993 by AT&T Jens of the US. Growth took off in mid-1994 with the promotion of commercial Internet applications. . menu section1 section2 section3section44The Absolute Commercialization of InternetCommercialization o

7、f Internet involved not only the development of competitive, private network services, but also the development of commercial products implementing the Internet technology. In parallel with the commercialization efforts that were highlighted by the Interop activities, the vendors began to attend the

8、 IETF meetings that were held 3 or 4 times a year to discuss new ideas for extensions of the TCP/IP suite. . menu section1 section2 section3section44The Absolute Commercialization of Internet Commercial efforts mainly comprised vendors providing the basic networking products, and service providers o

9、ffering the connectivity and basic Internet services. The Internet has now become almost a “commodity” service, and much of the latest attention has been on the use of this global information infrastructure for support of other commercial services. . menu section1 section2 section3section43.1.2 The

10、Concept and Characteristics of InternetInternet is an electronic network of computers that includes nearly every university, government agencies, research institutions and many commercial sites in the world. It started with four interconnected computers in 1969 and was known as ARPAnet. . menu secti

11、on1 section2 section3section43.1.3 The Compositions of Internet Hardware（1）Hub. （2）Router.（3）Switch Exchanger.（4）Server.（5）Client.（6）Modem.（7）Gateway. . menu section1 section2 section3section41Net Operation System (NOS)NOS includes special functions for connecting computers and devices into a LAN. （

12、1）Windows Server 2003.（2）UNIX.（3）Linux.3.1.3 The Compositions of Internet Hardware . menu section1 section2 section3section42Network（1）LAN.（2）WAN.（3）Intranet.（4）Extranet（5）Internet. 3.1.3 The Compositions of Internet Hardware . menu section1 section2 section3section43Client/Server ArchitectureA netw

13、ork architecture in which each computer or process on the network is composed by a client and a server. Client-server architectures are sometimes called two-tier architectures.Servers are powerful computers or processes dedicated to managing disk drives (file servers), printers (print servers), or n

14、etwork traffic (network servers). Clients are PCs or workstations on which users run applications. Clients rely on servers for resources. . menu section1 section2 section3section4Another type of network architecture is known as a peer-to-peer architecture because each node has equivalent responsibil

15、ities. These two architectures are widely used, and each has unique advantages and disadvantages. 3.1.3 The Compositions of Internet Hardware . menu section1 section2 section3section43.1.4 The Access Methods to Internet1PSTNPSTN is the short for Public Switched Telephone Network, which refers to the

16、 international telephone system based on copper wires carrying analog voice data. This is in contrast to newer telephone networks base on the digital technologies, such as ISDN and FDDI. Telephone service carried by the PSTN is often called plain old telephone service (POTS). . menu section1 section

17、2 section3section42ISDNISDN is abbreviation of integrated services digital network, an international communications standard for sending voice, video, and data over digital telephone lines or normal telephone wires. ISDN supports data transfer rates of 64 Kbit/s. 3.1.4 The Access Methods to Internet

18、 . menu section1 section2 section3section4There are two types of ISDN: Basic Rate Interface (BRI) consists of two 64 Kbit/s B-channels and one D-channel for transmitting control information. 3.1.4 The Access Methods to Internet . menu section1 section2 section3section4Primary Rate Interface (PRI) co

19、nsists of 23 B-channels and one D-channel (US) or 30 B-channels and one D-channel (Europe).3.1.4 The Access Methods to Internet . menu section1 section2 section3section43DDNDDN (Digital Data Network service) is a data communication service, transmitting signals via the lines of the telephone network

20、. Transmission speed is between 2 400 bit/s and 2.048 Mbit/s. It can support accurate and speedy transmission and reception of data for all kind of businesses.3.1.4 The Access Methods to Internet . menu section1 section2 section3section44DSLIt refers collectively to all types of digital subscriber l

21、ines, the two main categories being ADSL and SDSL. Two other types of xDSL technologies are High-data-rate DSL (HDSL) and Very-high-bit-rate DSL (VDSL). 3.1.4 The Access Methods to Internet . menu section1 section2 section3section45ATMATM is short for Asynchronous Transfer Mode, a network technology

22、 based on transferring data in cells or packets of a fixed size. The cell used with ATM is relatively small compared to units used with older technologies. 3.1.4 The Access Methods to Internet . menu section1 section2 section3section46Frame RelayFrame Relay is a packet-switching protocol for connect

23、ing devices on a WAN. Frame Relay networks in the US support data transfer rates at T-1 (1.544 Mbit/s) and T-3 (45 Mbit/s) speeds. In fact, you can think of Frame Relay as a way of utilizing existing T-1 and T-3 lines owned by a service provider. 3.1.4 The Access Methods to Internet . menu section1

24、section2 section3section47Optical Fiber AccessFTTH is the short for fiber-to-the-home, the installation of optical fiber from a telephone switch directly into the subscriber home. Fiber optic cable is an alternative to coaxial cable. FTTH is also referred to as fiber-to-the-building (FTTB), which in

25、cludes optical fiber that is installed directly into a home or enterprise. 3.1.4 The Access Methods to Internet . menu section1 section2 section3section48WAT (Wireless Access Technology)Any products tested and approved as “Wi-Fi Certified” (a registered trademark) by the Wi-Fi Alliance are certified

26、 as interoperable with each other, even if they are from different manufacturers. Typically, however, any Wi-Fi product using the same radio frequency (for example, 2.4 GHz for 802.11b or 802.11g, 5.2 GHz for 802.11a) will work with any other, even if not “Wi-Fi Certified”. . menu section1 section2

27、section3section43.2 Typical Internet Service3.2.1 Electronic Mail (E-Mail)1General Description of E-MailElectronic mail, sometimes called E-mail, is a computer basic method of sending messages from one computer user to another. The message can then be read at a later time. When E-mail is received on

28、 a computer system, it is usually stored in an electronic mailbox for the recipient to read later. . menu section1 section2 section3section42How Does It Work?In order for messages to be sent from one computer to another, messages need to be converted into digital form and forwarded to a computer tha

29、t acts as a mail server or post office. This mail server sorts and directs mails for users. The only way this mail server can direct mail through to all users, is by being connected to a network that all the users are also connected to. . menu section1 section2 section3section43Mailing ListIt is a l

30、ist of E-mail addresses identified by a single name, such as: mail-. When an E-mail message is sent to the mailing list name, it is automatically forwarded to all the addresses in the list. . menu section1 section2 section3section43.2.2 File Transfer Protocol (FTP)1An Introduction to FTPFTP is the I

31、nternet standard file transfer program. FTP enables you to transfer nearly any kind of file between most computers connected to the Internet by logging on to a remote computer solely for the purpose of file transfer. . menu section1 section2 section3section4most E-mail providers limit the size of ma

32、ilboxs on their servers, the size of attachments you may receive, and that there is no guarantee when you send E-mail how long it will take for the recipient to receive it or if it will even get there. This is why FTP comes in.3.2.2 File Transfer Protocol (FTP) . menu section1 section2 section3secti

33、on41An Introduction to FTPIf you need to transfer files between two computers, you could use FTP to do so. FTP stands for File Transfer Protocol and transfers files between an FTP server and another computer. FTP supports Automatic Resume. This means that if you are downloading the latest new game d

34、emo that is over 600 megs, and for some reason the download stops in the middle of the transfer, the FTP client will attempt on the next download of the same file, to continue from where you left off. . menu section1 section2 section3section42How to Connect to an FTP ServerThere are two approaches a

35、llowing users to connect to an FTP server. One is that anyone can log in anonymously, otherwise known as anonymous, or you can assign user names and passwords to people that they must use to log in to the server. The two most common ways connected to an FTP server is Web Browser or a specialized FTP

36、 client. 3.2.2 File Transfer Protocol (FTP) . menu section1 section2 section3section43How to Transfer FilesWhether you are connected to an FTP server via your web browser or an FTP client, you will be presented with a list of folders and documents that have files you can download to your computer. I

37、f you are using a web browser, you will click on the file you would like to download and it will prompt you to save it or open it. Unless you really know what it is you are downloading, you should save it to a directory that you will know how to find later, and open it from there.3.2.2 File Transfer

38、 Protocol (FTP) . menu section1 section2 section3section43How to Transfer FilesIf you are using an FTP client, you will be presented a list of the files that you can download. You should first specify where you would like downloads to save, then you can double click on the file to start the download

39、. When you are downloading, you can shut the FTP client and open the file from where it was stored. . menu section1 section2 section3section43.2.3 BBS, Blog & Instant Messaging1BBS BBS is the abbreviation of “Bulletin Board System”. BBS was initially used to transmit files and information with compu

40、ter through lines. Later for more users requirement, BBS was not just a Bulletin Board and included more services such as: discussing section, mail section, chat section, files sharing section etc. . menu section1 section2 section3section41BBS Main functions supported by different BBS now:（1）Support

41、 users to choose information in their interesting sections;（2）Periodically check new messages and selectively read them;（3）Deliver messages or articles;（4）Review other peoples messages or articles;（5）Get free soft wares and files transmit;（6）Interactive E-mail and instant chat in the same web. . men

42、u section1 section2 section3section41BBS Some BBS web addresses are domain names form, which can be loaded by telnet. But much more webs have “www” form. Now BBS of mainland and Taiwan Province of China both support Chinese BBS system and most of mainland BBS webs provide GB and BIG-5 Chinese interf

43、ace which is very convenient to intercostals users. . menu section1 section2 section3section42BlogThe full name of Blog is web log, which is another network communication method following E-mail and BBS. It can be understood as a publishing mode which expresses personal thought, has content ranked t

44、imely and is network updated continually. So blog web is a virtual place supporting netizen (Internet citizen or Internet users) to deliver their thoughts through Internet and it is frequency, brevity and personality. . menu section1 section2 section3section42BlogA Blog is a web page including brief

45、 letters updated frequently and ranked timely. Blog has various content and intention, some are super links and reviews, others are news and the more are dairies, photos, poems, essays and sci-fis. . menu section1 section2 section3section42Blog Many Blogs express peoples thinking and feelings but an

46、y others are collectively created on some special theme or common interests. Authors of those Blog are called “Blogger” or “Blog writer” who create web logs with super link and delegate a new life, work and study style. . menu section1 section2 section3section42BlogBlogs concept is embodied as: freq

47、uency, brevity and personality. Blog is a speech web run in every hour in every week, which provides speech place straight forward, wildly, thoughtfully and weirdly. . menu section1 section2 section3section42BlogDifference between Blog and BBS: （1）BBS is discussing and chat place for many people (li

48、ke an English corner).（2）BBS is open, free place, for an incompact group, servicing for the public to solve liberty of speech absence.（3）BBS organizes its letters and articles by time order and classifies those letters by some sort standards which cant be changed by users. . menu section1 section2 s

49、ection3section43Instant MessagingIM (instant messaging) is a kind of instant communication service which supports users to set up a chatroom on network. It includes all of E-mail functions, such as words, files and pictures transmittal etc. And also support instant messaging and speech and video cha

50、t with microphone and electronic camera. . menu section1 section2 section3section43Instant MessagingNow there are 50 instant messaging software in domestic market. QQ has absolute market share and other participants such as MSN Messenger, sina UC, Net POPO, Yahoo, Skype, Taobao etc. . menu section1

51、section2 section3section43Instant MessagingIM mainly uses such transmission protocols:（1）XMPP（2）SIMPLE（3）Jabber（4）CPIM（5）IRCP . menu section1 section2 section3section43.2.4 W W WWWW (World Wide Web) is a hypertext system based on hyperlink and the most popular information search program. WWW is tech

52、nically defined as a primal wide hyper media search criterions in order to visit huge files. . menu section1 section2 section3section43.2.4 WWWWWW adopts client/server model. Here server is a web server used to provide information services and client machine is client program running at client termi

53、nal, also called WWW browser. Web pages are transmitted between servers and browsers with HTTP. WWW provides users hypertext services world widely. Besides, WWW still provides traditional Internet services, such as Telnet, FTP, Gopher, Newsgroup, E-mail etc. . menu section1 section2 section3section4

54、There are five main reasons which make WWW so popular on Internet:（1）WWW is a graphical hypertext messages delivering and acquiring system.（2）WWW has nothing to do with platform.（3）WWW is distributing.（4）Every page of every site has its only one address called URL.（5）WWW is interactive.（6）WWW is dyn

55、amic.（7）Now, web 1.0 is widely used. . menu section1 section2 section3section43.3 TCP/IP3.3.1 TCP/IP ConceptionTCP/IP was firstly brought out by two researchers of Stanford University in 1973. In 1982, TCP/IP was adopted by UNIX BSD 4.1. Along with UNIXs success, TCP/IP gradually became standard pro

56、tocol of UNIX network. . menu section1 section2 section3section43.3.1 TCP/IP ConceptionTCP/IP is a set of protocols including TCP, IP and other protocols.TCP is transport control protocol which provides applied programs available communication connection. IP is internet protocol which makes Internet

57、 flexible to adapt to any web hardware and has almost not any request to basic web hardware. . menu section1 section2 section3section43.3.1 TCP/IP ConceptionTCP and IP are complementary, which make Internet work well under complicated environment. TCP/IP were designed so elaborate that it still can

58、satisfy communication need even now when so many computers connected to Internet are so fast and data quantity grows so speedy. . menu section1 section2 section3section43.3.2 The Hierarchy of TCP/IP TCP/IP has a hierarchy. It is convenient for designers to definite every layers task and target, whic

59、h makes the n layer of object computer receive exactly information from the n layer of source computer. TCP/IP has five layers (see Figure 3-1). . menu section1 section2 section3section4Figure 3-1 Hierarchy of TCP/IP LayersFunction descriptionapplicationConsist of applied softwares which could be vi

60、sited by users. All protocols observed by users at applied soft wares level belong to this layer, such as: FTP, SMTP, Telnet and HTTP etctransmissionTo transport data using transmission protocol, handle users information transported from application layer, plug additional explanation in every inform