1. The Internet and the Web:
Chapter 2
The Internet and the Web:
Infrastructure for
Electronic Commerce
Electronic Commerce

2. Objectives
General structure of the network of networks supporting the Internet and e-commerce
Protocols that move commerce across the Internet and send/receive
Internet utility programs to trace, locate, and verify the status of Internet host sites

3. Objectives
Popular Internet applications, including , Telnet, and FTP
History and use of Web markup languages, including SGML, HTML, and XML
HTML tags and links
Web client and server architectures and the messages they send to each other

4. Objectives
Differences and similarities between internets, intranets, and extranets
Options for connecting to the Internet, their cost and bandwidth tradeoffs

5. Technology Overview
Internet is the most obvious technology needed to conduct e-commerce
Other technologies are also required
Database software
Network switches and hubs
Encryption hardware and software
Multimedia support
Potential for business volume to double in less than a year

6. Packet-Switched Networks
Local and long distance telephone companies were early models in the 1950s
Single paths were created to connect two parties together, called circuit switching

7. Packet-Switched Networks
The Internet uses Packet switching
Files and messages are broken down into packets, which are electronically labeled with their origin and destination
The destination computer collects the packets and reassembles the data from the pieces in each packet
Each computer the packet encounters decides the best route towards its destination

8. Packet-Switched Network
and Message Packets
Figure 2-1

9. Open Architecture
Independent networks should not require any internal changes in order to be connected to the network
Packets that do not arrive at their destination must be retransmitted
Router computers do not retain information about the packets
No global control exists over the network

10. The TCP/IP Internet Protocol
Set of protocols developed by Vincent Cerf and Robert Kahn
Transmission Control Protocol (TCP)
Controls the assembly of a message into smaller packets before transmission, and reassembles them once received
Internet Protocol (IP)
Rules for routing packets from their source to their destination
Replaced NCP as used by ARPANET

11. TCP/IP Architecture
Figure 2-2

12. IP Address and Domain Names
Appears as a series of up to four separate numbers delineated by a period, often referred to as a “Dotted Quad”
Each of the numbers range from 0 to 255
First four numbers identify the network
Following numbers identify a node
Sample IP address:

13. IP Address and Domain Names
Uniform Resource Locator (URL)
Easier to remember than IP address
Consists of names and abbreviations
Contains at least two parts
First part contains the protocol used
Second part contains the location of the resource

14. Top-Level Domain Names
Figure 2-3

15. Other Internet Protocols
Hypertext Transfer Protocol (HTTP)
Responsible for transferring and displaying Web pages
Simple Mail Transfer Protocol (SMTP)
Specifies the exact format of a mail message
Post Office Protocol (POP)
Responsible for retrieving from a mail server

16. Other Internet Protocols
Interactive Mail Access Protocol (IMAP)
Latest protocol, may replace POP
Defines how a client program asks a mail server to present available mail
Download only selected messages, instead of all messages
View headers only
Create and manipulate mailboxes on the server

17. Other Internet Protocols
File Transfer Protocol (FTP)
Transfers files between TCP/IP-connected computers
Uses client/server model
Transfers both binary and ASCII text
Displays and manipulates remote and local computer file directories

18. Internet Utility Programs
Finger
Runs on UNIX computers and allows users to obtain limited information about other network users

19. Finger Program Output
Figure 2-4

20. Internet Utility Programs
Packet InterNet Groper (Ping)
Tests the connectivity between two Internet hosts
Determines if the host is active
Sends a packet and waits for a reply
Determines number of hosts (hops) between two specified hosts

21. Tracert and Other Route-Tracing Programs
TRACE RouTe (Tracert) traces the round trip path between a user’s computer and another computer on the Internet
Incorporates a Graphical User Interface (GUI) for a visual representation of the route

22. Tracing a Path Between Two Computers
Figure 2-5

23. Internet Applications: Electronic Mail
Began in the 1970s for use on the ARPANET
Most popular form of business communication
Can send documents, pictures, movies, worksheets, or other important pieces of information

24. Sending E-Mail Attachments
Figure 2-6

25. Internet Applications: Telnet
Allows users to log on to a remote computer that is attached to the Internet
Type commands to run on the remote host computer by using terminal emulation
Client software is available, and users can access Telnet through most Web browsers

26. Example of a Telnet Session
Figure 2-7

27. Internet Applications: FTP
Fastest way to deliver digital business information from one computer to another
Commonly used to download software packages and updates
Also used to upload files to the host computer for access from the Internet

28. An FTP Session
Figure 2-8

29. Markup Languages and the Web
Standard Generalized Markup Language (SGML)
Regulated ISO standard since 1986
Nonproprietary
Supports user-defined tags
Costly to set up
Expensive compared to HTML
Steep learning curve

30. Markup Languages and the Web
Hypertext Markup Language
Based on SGML
Easier to learn and support
Supports commonly used text markup features
Headings, title bars, bullets, lines, lists
Precise graphic positioning, tables, and frames
Standard language for Web pages

31. Markup Languages and the Web
Extensible Markup Language
Descendant of SGML
Defines which data to display, instead of how a page is displayed
Describes a page’s actual content, unlike HTML
Data-tracking capability

32. XML Example
Figure 2-9

33. Traditional vs. Hyperlinked Document Pages
Figure 2-10

34. More about HTML HTML tags
<tagname properties>Displayed information affected by tag</tagname>
<B>best</B> - Bolds the word “best”
<P align=“right”> - Aligns text to the right
HTML code defines the formatting of the page, but a page may look different on two different browsers

35. Web Page and Paragraph Tag With Right-Align Property
Figure 2-11

36. HTML Codes to Format Memo Page
Figure 2-12

37. Internet Explorer Display of Memo Page
Figure 2-13

38. More about HTML HTML Links
Anchor tags used to link to text within the same document, or on a distant computer
<A HREF=“address”>Visible link text</A>
<A HREF= University</A>
<A HREF=“#references”>References are found here</A>
Text between the anchors appears as a hyperlink

39. Hyperlink Structures Figure 2-14

40. HTML Version History Version 1.0 appeared in the summer of 1991
Version 2.0 was released in September 1995
Internet Explorer 2.0 and Netscape Navigator 2.0 appeared
Version 3.2 was released in 1997
Provided support for tables, complex numbers, and text flow around images

41. HTML Version History Version 4.0 was released in December 1997
Support for OBJECT tag and Cascading Style Sheets (CSS)
Internationalization for various languages
Accessibility features

42. HTML Editors Used to generate the HTML code
Simple text editors offer limited flexibility
Any word processor can be used
Web site builders offer more control
Microsoft FrontPage
Dreamweaver

43. Dreamweaver Site Builder Software
Figure 2-15

44. Web Clients and Servers
Client computers typically request services, including printing, information retrieval, and database access
Servers are responsible for processing the clients’ requests

45. Client/Server Structure of the WWW
Figure 2-16

46. Web Client/Server Communication
Two-Tier Client/Server
All communication takes place between the client on the Internet and the target server at the other end
Request message consists of:
A request line
Optional request headers
An optional entity body

47. Message Flow Between a
Web Client and Server
Figure 2-17

48. Server Response Message
Figure 2-18

49. Web Client/Server Communication Figure 2-19
Three-Tiered Client/Server
First tier is the client
Second tier is the Web server
Third tier are the applications and their databases
(Figure 2-19)

50. Internets, Intranets, and Extranets
Only selected individuals are allowed access
Low-cost way to distribute corporate information
Collect and group information for external dissemination
Infrastructure requirements are usually in place if PCs are on a LAN

51. Internets, Intranets, and Extranets
Connect companies with suppliers or other business partners
Provide the infrastructure for the coordination of purchases, EDI, and communications
Use the Internet for communicating among themselves

52. FedEx Ship Page
Figure 2-20

53. Internets, Intranets, and Extranets
Public Network
An extranet that allows the public to access its intranet
When two or more companies agree to link their intranets using a public network (such as the Internet)
Private Network
A leased-line connection that physically connects two intranets

54. Internets, Intranets, and Extranets
Virtual Private Network (VPN)
Uses public networks and protocols to send sensitive data by using “tunneling” or “encapsulation” - private passageways through the Internet
Designed to save money and create a competitive advantage by alliances formed with cooperating companies

55. Secure VPN Extranet
Figure 2-21

56. Internet Connections Options and Tradeoffs
Internet Service Providers (ISPs) offer connection choices to their users
Plain Old Telephone Service (POTS)
Existing telephone lines with modems
Bandwidth of 56Kbps (56,000 bits per second)
Integrated Services Digital Network (ISDN)
Bandwidths up to 128Kbps
Asymmetric Digital Subscriber Line (ADSL)
Upload at 640Kbps, download up to 9Mbps

57. Cable Modems Same broadband coaxial cable that serves cable television
Upstream bandwidths of Kbps
Downstream bandwidths of 1.5Mbps
Current “sweet spot” (optimal price and performance)

58. Internet Connection Choices
Figure 2-22