Electronic Commerce

1. Electronic Commerce 《电子商务概论（双语）》 • 开课班级：信息 B08-3.4 • 学　　时： 48 • 授课教师：付 媛

2. Summary小结 I. In last lecture, you learned that commerce (The buying and selling of goods, especially on a large scale, as between cities or nations) has been practiced in traditional ways for thousands of years. Electronic commerce is the application of new technologies, particularly Internet and Web technologies, to help individuals, businesses, and other organizations conduct business more effectively. 上一讲介绍了商务的含义（大宗商品的买卖活动）以及在过去几千年中它的传统运作方式。电子商务利用新技术（特别是互联网和WWW 技术）帮助个人、企业及其他组织改进商务活动。

3. Summary小结 II. Not all activities lend themselves to improve -ment with these technologies, but many do. Using EC, some businesses have been able to create new products and services, and others have improved the promotion, marketing, and delivery of existing offerings. Firms have also found many ways to use electronic commerce to improve purchasing and supply activities; identify new customers; and operate their finance, administration, and human resource management activities more efficiently. 并不是所有的活动都可以通过电子商务技术得到改进，但很多活动可以实施电子商务。通过采用电子商务，一些企业可以创造新产品或新服务，另外一些企业可以改进现有产品或服务的促销、营销及运输方式。企业可以通过很多方式实施电子商务，更有效地改善采购和供应活动，寻找新的顾客，改进财务、日常管理和人力资源管理。

4. Summary小结 • Key terms • Electronic commerce ( e 一commerce )电子商务 • Electronic business ( e 一business )电子商务 • Electronic data interchange ( EDI )电子数据交换 • Electronic funds transfer ( EFT )电子资金转账 • Business-to-business ( B2B )企业间的电子商务 • Business-to-consumer ( B2C )企业与消费者间的电子商务 • Business-to-government ( B2G )企业与政府间的电子商务

5. Summary小结 • Key terms • Activity 业务活动 • Business processes 业务流程 • Firm 企业 • Transaction 交易 • Transaction costs 交易成本 • Value added network ( VAN ）增值网 • Value chain 价值链 • Wire transfer 电子转账

6. PART 1 Chapter 2: Technology Infrastructure: The Internet And The World Wide Web

7. The contents of the section 1本节内容 1、Origins of the Internet互联网的起源 2、New Uses for the Internet互联网的新用途 3、Growth of the Internet互联网的增长 4、Emergence of the World Wide Web WWW 的兴起

8. 1、Origins of the Internet互联网的起源 • In the early 1960s, the U.S. Department of Defense became concerned about the possible effects of nuclear attack on its computing facilities. The Defense Department realized that the weapons of the future would require powerful computers for coordination and control. • 20 世纪 60 年代初期，美国国防部开始担心核攻击可能对其计算机设施带来的后果。国防部知道将来的武器需要功能强大的计算机进行协调和控制。

9. 1、Origins of the Internet互联网的起源 • So the Defense Department began exam-ining ways to connect these computers to each other and also connect them to weapons installations distributed all over the world. • 所以国防部开始想办法把这些计算机互相连接并把它们和遍布全球的武器装置连到一起。

10. 1、Origins of the Internet互联网的起源 • The Defense Department agency charged with this task hired many of the best communications technology researchers and, for many years, funded research at leading universities and institutes to explore the task of creating a worldwide network that could remain operational, even if parts of the network were destroyed by enemy military action or sabotage. • 国防部里接受此项任务的机构雇用了很多顶尖的通信技术专家，花了多年的时间委托一些著名的大学和研究所进行研究，目的是创造出一种全球性的网络，即使这种网络的一部分被敌人的军事行动或破坏活动所摧毁，整个网络还可以正常运行。

11. 1、Origins of the Internet互联网的起源 • Early computer networks established a single connection between sender and receiver for each telephone call, and that connection carried all data along a single path. When a company wanted to connect computers it owned at two different locations, the company placed a telephone call to establish the connection, and then connected one computer to each end of that single connection. • 早期的网络在每个电话的呼叫者和受话者之间都建立了一条单信道的连接，这个连接使所有的数据在一条路径上传输。如果一家公司想把分散在不同地点的计算机连接起来，它可以在用电话专线建立这个连接，所连接的两台计算机通过这个单信道连接进行通信。

12. 1、Origins of the Internet互联网的起源 • The Defense Department was concerned about the inherent risk of this single- channel method for connecting computers, and its researchers developed a different method of sending information through multiple channels. In this method, files and messages are broken into packets that are labeled electronically with codes for their origins, sequences, and destinations. You will learn more about how packet networks operate later in this part. • 国防部很担心这种单信道的计算机连接的风险，研究人员于是提出了通过多信道发送信息的新方法。这种方法要把文件和信息分解打包，每个信息包都扣上电子代码以标明它们的来源和目的地。这一部分就讲述这种包交换网络的工作原理。

13. 信息 A 报文1 报文2 报文n E B 从A点到D点传输 D C

14. 2、 New Uses for the Internet互联网的新用途 I. Although the goals of the Defense Depart-ment network were still to control weapons systems and transfer research files, other uses for this vast network began to appear in the early 1970s. E-mail was born in 1972 when a researcher wrote a program that could send and receive messages over the network. This new method of communicating became widely and quickly. 到20 世纪70 年代初期，尽管国防部这个网络的主要目的还是控制武器系统和传输研究文件，但人们开始为这个网络找到了一些新的用途。1972 年，一个研究者写出了一段可以通过网络发送和接收信件的程序，电子邮件就这样诞生了，并迅速得到广泛的使用。军事、教育和科研领域的网络用户不断地增加。

15. 2、 New Uses for the Internet互联网的新用途 II. In 1979, a group of students and progr-ammers at Duke University and the Univer-sity of North Carolina started Usenet, an abbreviation for User’s News Network. Usenet allows anyone who connects to the network to read and post articles on a variety of subjects. 1979 年，杜克大学和北卡罗来纳大学的一群学生和程序员创建了用户新闻网，它可使网络的任何用户阅读和张贴各种话题的文章。Usenet 发展至今已有一千多个专题，每个专题区域称为一个新闻组。

16. 2、 New Uses for the Internet互联网的新用途 III. Usenet allows anyone who connects to the network to read and post articles on a variety of subjects. Usenet survives on the Internet today, with over 1000 different topic areas that are called newsgroups. 它可使网络的任何用户阅读和张贴各种话题的文章。Usenet 发展至今已有一千多个专题，每个专题区域称为一个新闻组。

17. 2、 New Uses for the Internet互联网的新用途 IV. The explosion(爆发) of personal com-puter use during the 1980s also helped more people become comfortable with computers. In the late 1980s, these independent academic and research networks merged into what we now call the Internet. 到20 世纪80 年代末期，个人电脑的飞速发展也使更多人喜欢上了计算机。这些独立的学术和研究网络合并成了我们现在所熟知的互联网。

18. Number of Internet Host 互联网主机数量 In millions Year 3、Growth of the Internet互联网的增长

19. 3、Growth of the Internet互联网的增长 • The opening of the Internet to business activity helped dramatically increase its growth; however, there was another development that worked hand in hand with the commercialization of the Internet to spur its growth. That development was the World Wide Web. • 互联网对商务活动的开放导致了互联网的高速发展，然而，伴随互联网发展而发展的另一项技术也大大加快了互联网的进程，这项技术就是WWW。

20. 4、Emergence of the WWW 万维网的兴起 • The WWW is software that runs on computers that are connected to the Internet. The network traffic generated by WWW software is the largest single category of traffic on the Internet today, outpacing e-mail, file transfers, and other data transmission traffic. Two important innovations that became key elements of the WWW arehypertextandgraphical user interfaces. • WWW 是运行在连入互联网的计算机上的软件。目前WWW 是互联网上使用最广泛的应用，已经超过电子邮件、文件传输和其他数据传输。造成这种广泛应用的关键在于WWW的两项重要的创造发挥了作用。这两项技术是超文本和图形用户界面。

21. The contents of the section 2本节内容 1、PACKET-SWITCHED NETWORKS包交换网 2、INTERNET PROTOCOLS互联网协议

22. 1、PACKET-SWITCHED NETWORKS包交换网 • What? Why called? I. The Internet was designed to be resis-tant to failure. In a circuit-switched net-work(线路交换网络), a failure in any one of the connected circuits causes the connec-tion to be interrupted and data to be lost. Instead, the Internet uses packet switch-ing to move data between two points.

23. 1、PACKET-SWITCHED NETWORKS包交换网 • What? Why called? II. On a packet-switched network, files and e-mail messages arc broken down(分解) into small pieces(片断), called packets(包), that are labeled electronically(电子标签) with their origins(源头), sequences(次序), and destination addresses(目的地地址).

24. 1、PACKET-SWITCHED NETWORKS包交换网 • What? Why called? III. Packets travel from computer to computer along the interconnected networks(互联的网络) until they reach their destinations. Each packet can take a different path through the interconnected networks, and the packets may arrive out of order(不按次序). The destination computer collects the packets and reassembles(重新组装) the original file or e-mail message from the pieces in each packet.

25. 1、PACKET-SWITCHED NETWORKS包交换网 • Principle(工作原理) I. As an individual packet travels from one network to another, the computers through which the packet travels determine the best route(最优路径) for getting the packet to its destination. The computers that decide how best to forward each packet are called routing computers(路由计算机), router computers(路由器计算机), routers(路由器), gateway computers(网关), or border routers(边界网关) . because they act as the gateway from a LAN or WAN to the Internet because they are located at the border between the organization and the Internet

26. 1、PACKET-SWITCHED NETWORKS包交换网 • Principle(工作原理) II.The programs on router computers(路由器计算机) that determine the best path on which to send each packet contain rules called routing algorithms(运算法则). The programs apply their routing algorithms to information they have stored in routing tables(路由表) or configuration tables(配置表). This information includes lists of connections that lead to particular groups of other routers, rules that specify which connections to use first(优先使用), and rules for handling instances(处理) of heavy packet traffic(包流量) and network congestion(拥堵).

27. 1、PACKET-SWITCHED NETWORKS包交换网 • Principle(工作原理) III. Individual LANs and WANs can use a variety of different rules and standards for creating packets within their networks. The network devices that move packets from one part of a network to another are called hubs(集线器), switches(交换机), and bridges(网桥). Routers(路由器) are used to connect networks to other networks.

28. 1、PACKET-SWITCHED NETWORKS包交换网 • Principle(工作原理) As you can see, routers are an important part of the infrastructure of the Internet. Then a company or organization becomes part of the Internet, it must connect at least one router to the other routers that make up the Internet. IV. When packets leave a network to travel on the Internet, they must be translated into a standard format. • Routers usually perform this translation function.

29. 1、PACKET-SWITCHED NETWORKS包交换网 TECHNOLOGY INFRASTRUCTURE: THE INTERNET AND THE WORLD WIDE WEB技术基础：互联网和WWW • principle 主干网路由器 1、PACKET-SWITCHED NETWORKS包交换网 principle E | COM 共9条 贾 英 群 P61

30. 2、INTERNET PROTOCOLS互联网协议 • Protocol’ s four key rules • Independent networks should not require any internal changes to be connected to the network.（独立的网络在连入其他网络时不需要进行任何变更 ） • Packets that do not arrive at their destinations must be retransmitted (重发)from their source network(源节点). • Router computers act as receive(接收)-and-forward(转发) devices; they do not retain information about the packets that they handle. • No global(全局的) control exists over the network. （对网络没有全局的控制）

31. 2、INTERNET PROTOCOLS互联网协议 • TCP/IP • IP Addressing • Domain Names( DNS) • Web Page Request and Delivery(传输) Protocols • Electronic Mail( E-Mail) Protocols

32. 2、INTERNET PROTOCOLS互联网协议 I. TCP/IP • The Internet uses two main protocols: the Transmission Control Protocol (TCP) and the Internet Protocol (IP). • The TCP controls the disassembly(拆分) of a message or a file into packets before it is transmitted over the Internet, and it controls the reassembly(重组) of those packets into their original formats when they reach their destinations. • The IP specifies the addressing details for each packet, labeling each with the packet’s origination and destination addresses.

33. 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 网络标识 主机标识 主机标识 主机标识 网络标识 网络标识 二进制数 0、１ • • • 十进制数 十进制数 十进制数 十进制数 B类IP地址 C类IP地址 A类IP地址 2、INTERNET PROTOCOLS互联网协议 II. IP Addressing（IP 地址） • Using a 32-bit(32位) number to identify(识别) the computers connected to the Internet. This address is called an IP address. For example: “255.255.255.255”

34. 2、INTERNET PROTOCOLS互联网协议 II. IP Addressing（IP 地址） • IP addresses are assigned by three not-for-profit organizations: the American Registry for Internet Numbers (ARIN), the Reseaux IP Européens (RIPE), and the Asia-Pacific Network Information Center (APNIC). • IP 地址由三家非营利组织负责分配，即美国互联网号码注册中心（ARIN ）、欧洲lP 注册中心( RIPE ）和亚太地区网络信息中心（APNIC ）。

35. 2、INTERNET PROTOCOLS互联网协议 II. IP Addressing（IP 地址） • IP地址告急： • 由中国互联网络信息中心(CNNIC)等主办的2008 IP地址资源研讨会在天河软件园召开。会议透露，IPv4地址资源按照目前的分派速度只剩下830多天。 届时，如不采取措施，新网民将无法正常上网。 • IPv4地址即将耗尽。已经研究出新的IPv6地址代替。 • IPv6地址：将二进制数增加到128位。 　

36. 2、INTERNET PROTOCOLS互联网协议 III. Domain Names（域名 ） • The founders of the Internet were concerned that users might find the dotted(以小圆点标记) decimal(十进制) notation(标记法) difficult to remember. To make the numbering(编号方式) system easier to use, they created an alternative(替代的) addressing method that uses words. In this system, an address such as “www. course.com” is called a domain name.

37. 2、INTERNET PROTOCOLS互联网协议 III. Domain Names（域名 ）

38. 2、INTERNET PROTOCOLS互联网协议 III. Domain Names（域名 ）

39. 2、INTERNET PROTOCOLS互联网协议 III. Domain Names（域名 ）

40. 2、INTERNET PROTOCOLS互联网协议 IV. Web Page Request and Delivery Protocols（页面请求与传输协议） • The set of rules for delivering Web page files over the Internet is in a protocol called the Hypertext(超文本) Transfer Protocol (HTTP). When a user types a domain name into a Web browser’s (WWW浏览器) address bar(地址栏), the browser sends an HTTP-formatted message to a Web server computer(服务器) that stores Web page files. The Web server computer then responds by sending a set of files (one for the Web page and one for each graphic object, sound, or video clip(视频) included on the page) back to the client computer(客户机). These files are sent within a message that is HTTP formatted.

41. 2、INTERNET PROTOCOLS互联网协议 V. Electronic Mail Protocols（电子邮件协议） • Electronic mail, or e-mail, that is sent across the Internet must also be formatted according to a common set of rules. Most organizations use a client/server(客户机/服务器) structure to handle e-mail. The organization has a computer called an e-mail server that is devoted to (致力于）handling e-mail. The software on that computer stores and forwards e-mail messages.

42. 2、INTERNET PROTOCOLS互联网协议 V. Electronic Mail Protocols（电子邮件协议） 1.SMTP and POP are two common pro-tocols used for sending and retrieving (检索) e-mail. • SMTP 和POP 是两个用于发送和检索电子邮件的常用协议。

43. 2、INTERNET PROTOCOLS互联网协议 V. Electronic Mail Protocols（电子邮件协议） 2.Simple Mail Transfer Protocol (SMTP) specifies the format of a mail message and describes how mail is to be administered on the e-mail server and transmitted on the Internet。 • 简单邮件传输协议（SMTP ）规定了邮件信息的具体格式、电子邮件服务器上邮件的管理方式以及互联网上电子邮件的传输方式。

44. 2、INTERNET PROTOCOLS互联网协议 V. Electronic Mail Protocols（电子邮件协议） 3.An e-mail client program running on a user’s computer can request mail from the organization’s e-mail server using the Post Office Protocol (邮局协议)(POP). A POP message can tell the e-mail server to send mail to the user’s computer and delete it from the e-mail server.

45. The contents of the section 4本节内容 1、INTRANETS AND EXTRANETS内部网和外部网

46. 1、 INTRANETS AND EXTRANETS 内部网和外部网 • (一)INTRANETS内部网 • (二)EXTRANETS外部网 • (三)Public and Private Networks公共网络与专用网络 • (四)虚拟专用网 Virtual Private Network (VPN) • (五) INTERNET CONNECTION OPTIONS互联网接入方案

47. (一)INTRANETS内部网 • Definition(定义)： • Intranets are an excellent low-cost way to distribute internal(内部的) corporate(法人的) information. • Based on the client-server model, intranet requests for files, documents, or schematic(图表) drawings work the same way they do on the Internet. • An intranet uses Web browsers and Internet- based protocols, including TCP/IP, FTP, Telnet, HTML, and HTTP.

48. (一)INTRANETS内部网 • Advantages： • Because intranets are compatible(兼容) with the Internet, information from intranets can be shared among departments that use different technologies as well as among external(外部的) consumers. • Intranets are often the most efficient way to distribute internal corporate information, because producing and distributing paper is usually slower and more expensive than using Web-based communications.

49. (二) EXTRANETS外部网 • Extranets are networks that connect companies with suppliers, business partners, or other authorized(授权) users. Each participant in the extranet has access to the databases, files, or other information stored on computers connected to the extranet. • An extranet can be set up through the Internet, or it can use a separate network. Some extranets start out as intranets that eventually provide access of intranet data to select Internet users.

50. (三) Public and Private Networks 公共网络与专用网络 A public network is any computer network or telecommunications network that is available to the public. The Internet is one example of a public network. Although a company can operate its extranet using a public network, very few do because of the high level of security risks. The Internet, as you will learn in later chapters, does not provide a high degree of security in its basic structure.