中医药大学管理信息系统PPT-(9)课件.ppt

1、8.1 2006 by Prentice Hall8Chapter Telecommunications, Networks, and the Internet8.2 2006 by Prentice HallOBJECTIVES Describe the features of a contemporary corporate network infrastructure and key networking technologies Evaluate alternative transmission media, types of networks, and network service

2、s Assess the role of the Internet and the World Wide Web in a firms information technology infrastructure 8.3 2006 by Prentice HallOBJECTIVES (Continued) Identify and describe the most important tools for communication and e-business Identify and describe the challenges posed by networking and the I

3、nternet and management solutions 8.4 2006 by Prentice Hall Challenge: Outdated networking environment, high maintenance costs, and poor service to 19 schools and 8,000 students Solutions: Install a TCP/IP networking environment that handles both voice and data traffic, and supports intranet for teac

4、hers Standardize desktop operating systems and hardware Illustrates the importance of using Internet-based networking technologies to achieve business and service goalsOkanagan-Skaha School District Case8.5 2006 by Prentice HallTELECOMMUNICATIONS AND NETWORKING IN TODAYS BUSINESS WORLD A networking

5、and communications revolution led by Internet-based technologies 1 billion instant messages per day 4 billion e-mails each day 65 million music files downloaded8.6 2006 by Prentice HallTELECOMMUNICATIONS AND NETWORKING IN TODAYS BUSINESS WORLD Estimated 3.9 billion photos sent over the Internet $769

6、 billion spent in the United States on telecommunications equipment and services Today, networking and the Internet are synonymous with doing business. 8.7 2006 by Prentice HallTELECOMMUNICATIONS AND NETWORKING IN TODAYS BUSINESS WORLD Telecommunications spending in the United States, 20022007 Figur

7、e 8-1Source: Bureau of Economic Analysis, National Income and Product Accounts, 2004; and eMarketer and the Telecommunications Industry Association, 20048.8 2006 by Prentice HallTELECOMMUNICATIONS AND NETWORKING IN TODAYS BUSINESS WORLD Telecommunications environment provides connectivity by providi

8、ng communication channels for text, voice, and video images. The network infrastructure for a large corporation consists of many different kinds of networks for both data and voice communication. Most of these different kinds of networks are moving towards a common Internet foundation.The Business T

9、elecommunications Environment 8.9 2006 by Prentice HallTELECOMMUNICATIONS AND NETWORKING IN TODAYS BUSINESS WORLD Corporate Network Infrastructure Figure 8-28.10 2006 by Prentice HallTELECOMMUNICATIONS AND NETWORKING IN TODAYS BUSINESS WORLD The seven major trends in telecommunications: Rapid techno

10、logical innovation has resulted in a proliferation of new hardware devices and new alternatives for business communications. Continuing telecommunications deregulation has encouraged competition and created many alternatives. Networking and Communications Trends 8.11 2006 by Prentice HallTELECOMMUNI

11、CATIONS AND NETWORKING IN TODAYS BUSINESS WORLD Distinctions between telephone, cable television, Internet, and satellite telecommunication are blurred. Growing dominance of Internet technologies in voice, video, and data communications Rapid growth in “last-mile” high-speed broadband connections to

12、 homes and businessesNetworking and Communications Trends (Continued)8.12 2006 by Prentice HallTELECOMMUNICATIONS AND NETWORKING IN TODAYS BUSINESS WORLD Rapid growth in wireless telephone, wireless computer networks, and mobile Internet devices Growing scope of communication-intense services and pr

13、oducts Networking and Communications Trends (Continued)8.13 2006 by Prentice HallTELECOMMUNICATIONS AND NETWORKING IN TODAYS BUSINESS WORLD Declining transaction costs Declining agency costs Increased agility The Business Value of Telecommunications and Networking Business value impacts of the telec

14、ommunications and Networking are:8.14 2006 by Prentice HallTELECOMMUNICATIONS AND NETWORKING IN TODAYS BUSINESS WORLD Higher quality management decisions Declining geographical barriers Declining temporal barriers The extremely rapid growth in business networking and telecommunications results from

15、the extraordinary value of participating in networks like the Internet. The Business Value of Telecommunications and Networking (Continued)8.15 2006 by Prentice HallTELECOMMUNICATIONS AND NETWORKING IN TODAYS BUSINESS WORLD Metcalfes Law Figure 8-38.16 2006 by Prentice HallCONTEMPORARY NETWORKING IN

16、FRASTRUCTURE A network consists of two or more connected computers. Each computer on the network contains a network interface device called a network interface card (NIC). The connection medium for linking network components can be a telephone wire, coaxial cable, or radio signal in the case of cell

17、 phone and wireless local area networks. Networks and Corporate Infrastructure 8.17 2006 by Prentice HallCONTEMPORARY NETWORKING INFRASTRUCTURE The network operating system (NOS) routes and manages communications on the network and coordinates network resources. Networks also contain a switch or a h

18、ub acting as a connection point between the computers. Hubs are very simple devices that connect network components, sending a packet of data to all other connected devices. Networks and Corporate Infrastructure (Continued)8.18 2006 by Prentice HallCONTEMPORARY NETWORKING INFRASTRUCTURE A switch has

19、 more intelligence than a hub and can filter and forward data to a specified destination. Switches are used within individual networks. A router is a special communications processor used to route packets of data through different networks, ensuring that the message sent gets to the correct address.

20、 Networks and Corporate Infrastructure (Continued)8.19 2006 by Prentice HallComponents of a Simple Network CONTEMPORARY NETWORKING INFRASTRUCTURE Figure 8-48.20 2006 by Prentice HallCONTEMPORARY NETWORKING INFRASTRUCTURE Client/Server Computing Packet Switching TCP/IP and Connectivity Key Digital Ne

21、tworking Technologies 8.21 2006 by Prentice HallCONTEMPORARY NETWORKING INFRASTRUCTURE Client/server computing is a distributed computing model in which much of the processing power is located within small, inexpensive client computers. The powerful clients are linked to one another through a networ

22、k that is controlled by a network server computer. The server sets the rules of communication for the network and provides every client with an address so others can find it on the network.Client/Server Computing: 8.22 2006 by Prentice HallCONTEMPORARY NETWORKING INFRASTRUCTURE In packet-switched ne

23、tworks, messages are first broken down into small bundles of data called packets. These packets are sent along different communication paths and then the packets are reassembled once they reach their destinations. Packet Switching: 8.23 2006 by Prentice HallCONTEMPORARY NETWORKING INFRASTRUCTURE Pac

24、ket switching makes more efficient use of the communications capacity of a network. The packets include information for directing the packet to the right address and for checking transmission errors along with the data. Packet Switching: (Continued)8.24 2006 by Prentice HallPacked-Switched Networks

25、and Packet Communications CONTEMPORARY NETWORKING INFRASTRUCTURE Figure 8-58.25 2006 by Prentice HallCONTEMPORARY NETWORKING INFRASTRUCTURE TCP/IP is the communications protocol used by the Internet and all Internet devices. TCP/IP provides for breaking up digital messages into packets, routing them

26、 to the proper addresses, and then reassembling them into coherent messages. TCP/IP uses a suite of protocols: TCP and IP.TCP/IP and Connectivity: 8.26 2006 by Prentice HallCONTEMPORARY NETWORKING INFRASTRUCTURE Handles the movement of data between computers Establishes a connection between the comp

27、uters, sequences the transfer of packets, and acknowledges the packets sent Transmission Control Protocol (TCP): 8.27 2006 by Prentice HallCONTEMPORARY NETWORKING INFRASTRUCTURE Responsible for the delivery of packets Includes the disassembling and reassembling of packets during transmission Interne

28、t Protocol (IP): 8.28 2006 by Prentice HallThe TCP/IP Reference ModelCONTEMPORARY NETWORKING INFRASTRUCTURE Figure 8-68.29 2006 by Prentice HallCONTEMPORARY NETWORKING INFRASTRUCTURE Twisted Wire Coaxial Cable Fiber Optics and Optical Networks Wireless TransmissionPhysical Transmission Media The dif

29、ferent kinds of physical transmission media used by the networks are:8.30 2006 by Prentice HallFunctions of the Modem CONTEMPORARY NETWORKING INFRASTRUCTURE Figure 8-78.31 2006 by Prentice HallTypes of Networks CONTEMPORARY NETWORKING INFRASTRUCTURE Type Area Local Area Network (LAN) Up to 500 meter

30、s (half a mile); an office or floor of a building Campus Area Network (CAN) Up to 1,000 meters (a mile); a college campus or corporate facility Metropolitan Area Network (MAN) A city or metropolitan area Wide Area Network (WAN) Transcontinental or global area 8.32 2006 by Prentice HallNetwork Topolo

31、gies CONTEMPORARY NETWORKING INFRASTRUCTURE Figure 8-88.33 2006 by Prentice HallCONTEMPORARY NETWORKING INFRASTRUCTURE Frame relay: Packages data into frames for high-speed transmission over reliable circuits that require less error checking than packet switchingBroadband Network Services and Techno

32、logies A number of network services and technologies are available to companies that need high-speed transmission or access to the Internet. 8.34 2006 by Prentice HallCONTEMPORARY NETWORKING INFRASTRUCTURE Asynchronous Transfer Mode (ATM): Parcels data into uniform 53-byte cells for high-speed trans

33、mission; can transmit data, video, and audio over the same network Integrated Services Digital Network (ISDN): Dial-up network access standard that can integrate voice, data, and video services Broadband Network Services and Technologies (Continued)8.35 2006 by Prentice HallCONTEMPORARY NETWORKING I

34、NFRASTRUCTURE Digital Subscriber Line (DSL): Series of technologies for high-capacity transmission over copper wire Cable modem: Service for high-speed transmission of data over cable TV lines that are shared by many users T lines: Dedicated lines for high-speed secure data transmission and Internet

35、 connection Broadband Network Services and Technologies (Continued)8.36 2006 by Prentice HallTHE INTERNET A network composed of computers and other devices that are logically linked together by a unique address space based on the Internet ProtocolTechnically, the Internet is a global information sys

36、tem defined by three characteristics: 8.37 2006 by Prentice HallTHE INTERNET (Continued) A network where network devices are able to support communications using TCP/IP or other compatible protocols A network that provides high-level services layered on a communication and network infrastructure 8.3

37、8 2006 by Prentice HallTHE INTERNET A Domain Name System (DNS) converts IP addresses to English-like domain names. The domain name is the name that corresponds to the unique 32-bit numeric IP address for each computer connected to the Internet. Internet Addressing, Architecture, and Governance Every

38、 device connected to the Internet has a unique 32-bit numeric IP address.The Domain Name System: 8.39 2006 by Prentice HallTHE INTERNET DNS servers maintain a database containing IP addresses mapped to their corresponding domain names. To access a computer on the Internet, users need only specify it

39、s domain name. Internet Addressing, Architecture, and Governance (Continued)The Domain Name System:8.40 2006 by Prentice HallThe Domain Name System THE INTERNET Figure 8-98.41 2006 by Prentice HallTHE INTERNET Internet Protocol version 4 (IPv4): A 32-bit string of numbers organized into four sets of

40、 numbers ranging from 0 to 255; contains up to 4 billion addresses Internet Protocol version 6 (IPv6): 128-bit addresses, contains over a quadrillion possible unique addresses Limitations on IP Addresses: IPv4 and IPv6: 8.42 2006 by Prentice HallTHE INTERNET Internet Architecture: Internet Network A

41、rchitecture Figure 8-108.43 2006 by Prentice HallTHE INTERNET Internet Architecture Board (IAB) Internet Corporation for Assigned Names and Numbers (ICANN)Internet Governance: No one “owns” the Internet, however, worldwide Internet policies are established by the following organizations: 8.44 2006 b

42、y Prentice HallTHE INTERNET Internet Network Information Center (InterNIC) Internet Engineering Steering Group (IESG) Internet Engineering Task Force (IETF) Internet Society (ISOC) World Wide Web Consortium (W3C) Internet Governance: (Continued)8.45 2006 by Prentice HallTHE INTERNET E-mail: Person-t

43、o-person messaging; document sharing Usenet newsgroups: Discussion groups on electronic bulletin boards LISTSERVs: Discussion groups using e-mail mailing list servers Chatting and instant messaging: Interactive conversations Major Internet Services Table 8-68.46 2006 by Prentice HallTHE INTERNET Tel

44、net: Logging on to one computer system and doing work on another FTP: Transferring files from computer to computer World Wide Web: Retrieving, formatting, and displaying information (including text, audio, graphics, and video) using hypertext links Major Internet Services (Continued)Table 8-6 (Conti

45、nued)8.47 2006 by Prentice HallTHE INTERNET Client/server Computing on the Internet Figure 8-118.48 2006 by Prentice HallTHE INTERNET The World Wide Web: Hypertext Web servers Searching for information on the Web The Internet and Business Value 8.49 2006 by Prentice HallTHE INTERNET Major Web Server

46、 Providers Figure 8-12Source: Based on data from Netcraft Web Server Survey, July 2004, 2006 by Prentice HallTHE INTERNET The Internet lowers search costs Search engines Intelligent agents and shopping bots Broadcast and push technology The semantic Web Searching and Finding Information on the Inter

47、net 8.51 2006 by Prentice HallTHE INTERNET Intranets: An intranet is an internal organizational network that provides access to data across a business firm. Extranets: Allow authorized vendors and customers to have limited access to its internal intranet Intranets and Extranets8.52 2006 by Prentice

48、HallTECHNOLOGIES AND TOOLS FOR COMMUNICATIONAND E-BUSINESS E-Mail Chatting and Instant Messaging Electronic Discussion Groups 8.53 2006 by Prentice HallTECHNOLOGIES AND TOOLS FOR COMMUNICATIONAND E-BUSINESS Groupware: Provides capabilities for supporting enterprise-wide communication and collaborati

49、ve work Teamware: Enables companies to implement collaboration applications easily that can be accessed using Web browser softwareGroupware, Teamware, and Electronic Conferencing8.54 2006 by Prentice HallTECHNOLOGIES AND TOOLS FOR COMMUNICATIONAND E-BUSINESS Electronic conferencing tools: Provides a

50、 virtual conference table where participants can view and modify documents and slides or share their thoughts and comments using chat, audio, or video Groupware, Teamware, and Electronic Conferencing(Continued)8.55 2006 by Prentice HallTECHNOLOGIES AND TOOLS FOR COMMUNICATIONAND E-BUSINESS Internet