Chapter 7The Internet, Intranets,
and Extranets
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Learning Objectives
When you finish this chapter, you will
Know what the Internet is.Know the features for information exchange that can be conducted over the World Wide Web. Understand how the Web facilitates electronic commerce. Be able to generate basic ideas for new business ventures utilizing the Web.Appreciate the major risks and limitations of using the Web for business activities.
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Enterprise Networking and Internetworking
Enterprise Networking
An arrangement of the organization’s hardware,software, network, and data resources to put morecomputing power on the desktop and create a company wide network linking many smaller networks.
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Enterprise Networking and Internetworking
Internetworking
The linking of separate networks, each of whichretains its own identity, into an interconnectednetwork.
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What is the Internet?
The Development of the Internet
ARPANET (Advanced Research Project Agency Network ) was an open system designed for the free flow of information, but available only to members of academic institutions and some of the defense industry.
U.S. government decided to split the network into a civilian one and a military one.
Civilian network became the Internet
Internet is now a network of networks.
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What is the Internet?
Figure 7.1 The Internet connects millions of servers.
(Internet is not, and cannot, be controlled by anyone)
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What is the Internet?
Internet Service Provider
A commercial organization with a permanentthat sells temporary connections to subscribers.
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What is the Internet?
TCP/IP To join the Internet, an existing network
needs only to pay a small registration fee and agree to certain standard based on the TCP/IP reference model.
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What is the Internet?
TCP/IPApplication
Presentation
Session
Transport
Network
Data Link
Physical
Application
Transport
Internet
Network Interface
OSI TCP/IP
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What is the Internet?
TCP/IP
Application
Transport
InternetProtocol
NetworkInterface
(transmission control protocol)
Datagrams
Segment
Message
ftp, http, smtp,dns, …
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What is the Internet?
Growth of the InternetNumber of servers
From a few hundred in 1993, to more than 43,000,000 by mid-1999
Number of usersMore than 200 million; increased rapidly during 1999
Commercial Online ServicesCompanies like America Online provide “online” service to paying subscribers on their private networks.
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What is the Internet?
Figure 7.2 World growth of the Internet
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What is the Internet?
Figure 7.3 The number of Internet domain servers continues to grow
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Internet Technology and Service
Client/Server Technology
ServerClient
Web Browser
e-mailWeb pages
request
response
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Electronic Mail (E-Mail)
Internet Tools for Communication
Person to person messaging; document sharing
E-Mail Address
identifier@domain name
unique node on the internet
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Internet Domains
A domain name is assigned to each IP address.
Internet servers are grouped into different domains. (Function, Location)
Domain names are registered by one of a group of companies authorized to assign unique names.
Internet Tools for Communication
17Figure 7.4 Examples of Internet address suffixes
Internet Tools for Communication
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UseNet NewsGroups
Internet Tools for Communication
Usenet newsgroups are worldwide discussion groupsin which people share information and ideas on a definedtopic. Discussion takes place in large electronic bulletinboards where anyone can post messages for others to read.
ListServ
On-line groups using e-mail broadcast from mailing listservers for discussions and messaging.
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Chatting
Internet Tools for Communication
Chatting allows two or more people who are simultaneouslyconnected to the Internet to hold live, interactiveconversations.
Instant Messaging
Chat service that allows participants to create their ownprivate chat channels so that a person can be alerted whenever someone on his or her private list is on-line toinitiate a chat session with that particular individual.
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Telnet
Internet Tools for Communication
Network tool that allows someone to log on to onecomputer system while doing work on another.
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Information Retrieval on the Internet
FTP (File transfer protocol)
Tool for retrieving and transferring files from a remotecomputer
Gopher
A tool that enables the user to locate information storedon internet servers through a series of easy-to-use,hierarchical menus
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The World Wide Web
The World Wide Web is at the heart of the explosion in the business use of the Net.
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The World Wide Web
Hypertext transfer protocol (HTTP)The communication standard used to transfer pages on the Web. Defines how messages are formatted and transmitted.
Hypertext Mark-Up Language (HTML)Code for tagging Web files for display
BrowsersSoftware to access the Web
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The World Wide Web
Home Page and Web Side
A WWW text and graphical screen display that welcomesthe user and explains the organization that has establishedthe page
Home Page
Web Page
Web Page
Web Page
Web PageWeb Side
Webmaster
in charge
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The World Wide Web
Uniform Resource Locator (URL)
The address of a specific resource on the Internet.
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The World Wide Web
Creating Web FilesHTML
System of standardized “tags” that format elements text, graphics, and animation
Web page editorsTranslate well-known or intuitive commands into code
Java, ActiveX, and XMLWeb scripting languages
Common Gateway Interfaces (CGI) and FormsAllow a computer that is accessing a particular Web site to have some similar functions
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The World Wide Web
Figure 7.5 How a CGI works
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The World Wide Web
Searching for Information on the Web
Search engine: A tool for locating specific sitesor information on the Internet.
Shopping bot: Software with varying levels ofbuild-in intelligence to help electronic commerceshoppers locate and evaluate products or servicethey might wish to purchase.ex:www.mysimon.com
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The World Wide Web
Searching for Information on the Web
Broadcast and “Push” Technology (Channels)
Push Technology: Method of obtaining relevant informationon networks by having a computer broadcast information directly to the user based on prespecified interests
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Intranets and Extranets
IntranetA within-organization computer network that uses Internet technologies to communicate
Extranet Uses Internet technologies to facilitate communication and trade between an organization and its business partners, such as suppliers
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Intranets and Extranets
Intranet Technology
Firewalls: Hardware and software placed betweenan organization’s internal network and an externalnetwork to prevent outsiders from invadingprivate networks.
Firewall Server
Client
Client
Client
Internet
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Intranets and Extranets
Figure 7.6 An intranet, an extranet, and the Internet from an individual user’s perspective
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Intranets and Extranets
Figure 7.7 Internet, intranet, and extranet potential for productivity enhancement
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Intranets
Figure 7.8 Savings resulting from the Internet, intranet, and extranet e-commerce
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Establishing a Web Site
Site Name
Points of Presence ( 入網點 )
Line Capacity
Site Maintenance
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Establishing a Web Site
Figure 7.9 Transfer times of a 10-MB file by different media
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Business on the Internet
Business-to-Business Trading $43 billion - 1998 -> $1.3 trillion 9% by 2003 in USA
Electronic Data Interchange
Exchanges and Auctions ( 拍賣 )
E-catalogs
XML and EDI
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Business on the Internet
Business-to-Consumer TradingAdvertising
PortalsFree Internet applications
E-ShoppingE-PaymentAuctions and reverse auctionsSelling contentSelling softwareData pushStock trading for all
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Business on the Internet
Figure 7.10 Web-shopping benefits
The additional benefits to organization?
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Figure 7.11 Estimated unique visitors to individual Web sites during 8/09/99-8/15/99
Business on the Internet
Web Demographics
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Business Considerations
Web Costs
The least costly sites are those constructed simply to showcase the company’s products or services.
The most expensive sites are those designed to enable electronic commerce. (B2B>B2C)
Electronic commerce server software
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Business Considerations
Electronic Commerce Server Software
Software that provides functions essential for running e-commerce Web sites, such as setting up electronic catalogs and storefronts and processing customer purchases.
Ex: Commerce Server and BizTalk Server Websphere Commerce Suite
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Business Considerations
Figure 7.12 The average cost to a company offering a Web site for electronic commerce
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Business Considerations
Rules for Successful Web Sites
Target the right customers Ex: Pay for ad banners and links at sides
Own the customer’s total experience
Ex: Marketing to one
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Rules for Successful Web Sites
Business Considerations
Let customers help themselves
Ex: get information any time including after-the-sale information
Help customer do their job
Ex: Free ASP
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Business Considerations
Rules for Successful Web Sites
Personalize the service
Be proactive
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Business Considerations
Figure 7.13 Do’s and Don’ts in Web site construction for commercial purposes
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Business Considerations
Risks to OrganizationsComputer virusesInterception of passwords and codes by an unauthorized hackerInterception of charge account numbers - encryptionIllegal or socially objectionable use of a sitePotential misrepresentation
Risks to ConsumersEavesdropping and interception Misrepresentation
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Next Generation Internet: Broadband andInternet2
Internet2
Research network with new protocols and transmission speeds that provides an infrastructure for supportinghigh bandwidth Internet applications
University Corporation for Advanced Internet Development(UCAID)NASADARPANext Generation Internet (NGI)
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Next Generation Internet: Broadband andInternet2
GigaPoPs 全名 Gigabit capacity Point of Presence ,是第二代網際網路 的區域連結與服務中心。它的配備包含一個或多個高容量、功能先進的封包 (Packet) 資料轉接路由器 (Router ) ,至少能夠支援 OC-12 (622 Mbps) 的傳輸速度。事實上,它結合了許多網路技術,包括SONET 、非同步傳輸模式 (ATM ) 、網際網路通訊協定 (IP ) ( 含 IPv4 和網際網路通訊協定第6版 (IPv6) ) 、路由協定 (MOSPF , BGP) 、 QoS協定 (RSVP , RTP) 等。
GigaPoP 又稱 I2SC (Internet2 Service Center) ,為分散於全美各地的地區性高效能網路訊務集合中樞點,具有 Gbps 交換及路由的功能,可連接各式樣的服務介面,並可連接網路服務供應商以提供網際網路 (Internet) 原有的服務。
gigaPoPs
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Next Generation Internet: Broadband andInternet2
Quality of Service Level
Under Internet2 different types of packets could beassigned different levels of priority as they travel overthe network.