Presentation on theme: "Chapter 3 Networks and Telecommunications"— Presentation transcript:
1Chapter 3 Networks and Telecommunications Introduction to MISChapter 3Networks and Telecommunications
2Networks Internal Internet External Teamwork Communication Scheduling SharingInternetExternalSuppliersCustomersBanks
3Outline Introduction Components of a Network Network Structure Sharing DataSharing HardwareSharing SoftwareComponents of a NetworkComputersMediaConnection DevicesSoftwareNetwork StructureShared MediaSwitchedStandardsThe InternetHow the Internet WorksInternet 2Mobile CommerceGlobal TelecommunicationsTechnical ProblemsPolitical ComplicationsCultural IssuesCommentCases: Specialty RetailAppendix: Creating Web Pages
4Sharing Data: Transactions InternetDatabase ManagementSystem and Web Server
5Sharing Data: Decisions & Searches Teamwork & joint authorshipFile Server and DatabaseTeam DocumentDataandToolsReport andComments
6Sharing Data: E-mail Internet 2. Message transferred to account on server.3. Transferred via the Internet to the destination account.4. Message received when user checks .1. User creates message.
8Hardware Sharing Printers Storage Processors tape drive(backup)Corporate orexternal computeraccessWorkstationsShared PrinterServerFiles are transferred from workstations to the server.Software automatically copies files to tapes.LAN administrator can restore files if needed.
9Packet-Switched Networks Data, Voice, VideoAll converted to packetsPacket has data, destination, and source addressSwitched servicesPackets routed as neededReassembled at destinationVoiceSent as packets:B2ChicagoNew YorkCA41EAtlantaDallas35DComputerSent as packets: A B C D E
10Network Components Computers Media Connection devices Internet Servers Work stationsMediaCablesFiber opticRadioInfraredConnection devicesPersonal ComputerPersonal ComputerLAN cardLAN cardInternetLAN cardLAN cardRouter or SwitchFirewallShared PrinterServer
11Server Scalability Sun 10000 Sun 3800 Sun Ultra 5 Server farms distribute the workload. Add more computers for more power.Sun 10000Increasing performance within a product family.Sun 3800Rack mount server farm.CompaqSun Ultra 5
12Network Transmission Media ElectricityFiber opticsRadio wavesFiber Optic CableExample:Long distance phone linesreflective claddingTwisted PairExample:Local phone linesglass or plasticRadio or Micro WavesExample:Cellular phonesCoaxialExample:Cable TVantennaShield
13Fiber Optics Faster More data Less magnetic interference Long stretches without repeaters900 copper wires can be replaced by one fiber optic line (for telephone connections).
17Shared ConnectionsWith shared connections, machines have to take turns, and congestion can slow down all connections.With switched connections, each computer has the full bandwidth of the connection at all times. Performance depends on how fast the switch can handle connections.
18Time Division A B A C A C A C D Computers A and B split their messages into packets and sharethe transmission medium by taking turns sending the data.
19Frequency Division A B frequency A C C D 3500 HzCCDComputers A and B split the frequency: A uses a higher spectrum.By listening only to the assigned frequency, multiple transmissionscan occur at the same time.
20Spread Spectrum frequency A B C D timeSharing a medium by both frequency and time is one methodof spread spectrum transmission. It is efficient for many computersbecause the full bandwidth can be utilized over time and frequency.
21Wireless Communication Microwave transmissions are used to provide communications for cellular phones and laptop computers. As prices of phones, portable computers, and communication costs decrease, increasing numbers of workers are choosing wireless technologies.
22Connecting Networks The need for standards A changing environment InternetBackbone fiber opticRouters or SwitchesSwitchHubHubRadio-based network
27TCP/IP Reference Model 4. Application3. Transport (TCP)2. Internet (IP)1. PhysicalMessageHeader 3MessageTrailer 3Header 2Header 3Header 3MessageMessageTrailer 3Trailer 3Trailer 2Header 1Header 2Header 3Header 3MessageMessageTrailer 3Trailer 3Trailer 2Trailer 1
28TCP/IP Reference Application Transport Internet Protocol (IP) Subnet Mail, Web, FTPAuthentication, compression, user servicesTransportPacketize data and handle lost packetsEstablish connections through numbered portsInternet Protocol (IP)Route packets to destinationRequires unique host addresses: IPv4=32-bit; IPv6=128-bitRequires standards and cooperationSubnetPhysical connectionsTransfers bits with some form of error correction
29ISO-OSI Reference Model Layer 7ApplicationPresentationSessionTransportNetworkData LinkPhysicalApplicationPresentationSessionTransportNetworkData LinkPhysicalOriginal DataLayer 6TranslateLayer 5Sign on and resourcesLayer 4Data PacketLayer 3Add routing dataRLayer 2Addresses &Error CheckARCLayer 1ARCARCPhysical Media
30Introduction to the Internet No controlServicesMailTelnetFTPWWWWEB searchingAltaVistaHotBotLycosWebCrawlerYahooThe Internet
31How the Internet Works Network service provider (NSP) OC3: 155.52 Mbps T1: MbpsT3: MbpsBackbonenetworkInternetserviceprovider (ISP)PhonecompanyPhonecompanyCablecompanyDial-up: KbpsISDN: 128 KbpsDSL: Kbps - 6 MbpsCable: 1 to 10 MbpsCompanyWeb siteIndividual
32Internet Connections Backbone providers Phone companies AT&TGTEWorldcom/MCISprintQwestNetwork service providers1998: 39AGISCable & WirelessIBMMCI/WorldcomUUNetPhone companiesRegional Bell operating companies (RBOCs) (6)Competitive local exchange carriers (CLECs) (new)Cable companiesAT&TCablevisionRegional.SatelliteDirect SatelliteStarbandInternet service providersAmerica OnlineMicrosoft NetworkEarthlink
33M-Commerce Internet access everywhere Cell phones PDAs Laptops Great potentialLimited usabilityBetter than voice?
34Cell Phones and Wireless Communication Wireless cells work by handing off the wireless connection to the next tower as the caller moves.Connections to multiple towers at one time enables the system to triangulate to get a fairly precise location of the cellular device--even when it is not in a call.Location knowledge will make it possible (although perhaps not desirable) to offer new business opportunities as people move into range.
35Global Telecommunications Technical problemsMultiple standardsLanguageDeveloping nationsTime zonesLimits to space & wavesPolitical complicationsTransborder data flowsTaxesPrivacyAccessibilityCultural issuesWhat is an object?Management & control
40Appendix: Sample HTML <HTML> <HEAD> <TITLE>Sample HTML Page</TITLE></HEAD><BODY><H1>Section One</H1><P>This is a sample paragraph on a sample page.</P></BODY></HTML>
41Appendix: Publishing Files AccessibleWebpagesInternet orintranetInitialpagesWeb serverTransfer methods:Microsoft Front Page extensionsFTP: file transfer protocolYour computer
42Web Development HintsStart with a tool like Microsoft Word (or Front Page, etc.).Get a good graphics packageKeep page size small30, ,000 bytes typically takes secondsFirst develop the pages on your own computer.Test all links.Transfer later.Use style sheets.Consistency.Ease of change.Study design elements and art.Formal training/art classes.Study other sites.Watch for and create trends.