Information Systems - Chapter 6: Telecommunications and Networks

Chapter 6Telecommunications and NetworksLearning ObjectivesUnderstand the concept of a networkApply Metcalfe’s Law in understanding the value of a network.Identify several major developments and trends in the industries, technologies, and business applications of telecommunications and Internet technologies.Provide examples of the business value of Internet, intranet, and extranet applications.Learning ObjectivesIdentify the basic components, functions, and types of telecommunications networks used in business.Explain the functions of major components of telecommunications network hardware, software, media, and services.Explain the concept of client/server networking.Understand the two forms of peer-to-peer networking.Explain the difference between digital and analog signals.Learning ObjectivesIdentify the various transmission media and topologies used in telecommunications networks.Understand the fundamentals of wireless network technologies.Explain the concepts behind TCP/IP.Understand the seven layers of the OSI network model.Section 1Telecommunications and NetworksII. The Concept of a Network The Concept of a Network – an interconnected/interrelated systemMetcalf’s Law – the utility (use) of a network equals the square of the number of usersIV. The Business Value of Telecommunications Networks Cut costs, shorten lead/response times, improve collaboration, support e-commerceThe Internet Revolution – a “network of networks”, the largest and most important network, constantly expandingInternet Service Providers (ISP) – provides easy access to the InternetInternet Applications – browsing the Net, email, instant messagingBusiness Use of the Internet – the Internet adds value to every prt of the business cycleThe Business Value of the InternetV. The Role of IntranetsIntranet – a private internal network using Internet technologiesThe Business Value of Intranets – an enterprise information portal supporting communications and collaborationCommunications and Collaboration – improved by IntranetsWeb Publishing – developing and publishing hyperlinked multimedia documentsBusiness Operations and Management – develop/deploy critical applications supporting operations and managerial decision makingIntranet Portal Management – managed by IS/IT professionalsVI. The Role of Extranets Extranet – A private network using Internet technologies (intranet) opened to select external entities for purposes of communicationsPurpose – interconnect the business with its suppliers/customers/business partnersSection 2Telecommunications Network AlternativesII. Telecommunications Network Model – 5 basic components:Terminals – any input/output device to transmit/receive dataTelecommunications Processors – support data transmission/reception between terminalsTelecommunications Channels – media over which messages are sentComputers – interconnected by telecommunications networksTelecommunications control software – programs to control telecommunications activities and functionsIII. Types of Telecommunications NetworksA Network is defined by its geographic area and who owns the equipmentWide Area Networks (WAN) – between cities/large geographic areas, LANs connected by common carrier or leased linesMetropolitan Area Networks (MAN) – LANs connected over a specific geographical areaLocal Area Networks (LAN) – equipment owned by the firm, short distances, usually within a single building (or room)III. Types of Telecommunications NetworksVirtual Private Networks (VPN) – a network using the Internet as a backbone but incorporating security for privacyClient/Server Networks – a powerful, central computer (server) providing information and processing (services) to multiple end-user computers (clients)Network Computing – a minimally-powered browser-based computer obtains its data and processing from the InternetIV. Digital and Analog SignalsAnalog (continuous) – any value between the maximum/minimum value is possible (e.g., any frequency between 20hz and 20K hz)Digital (discrete) – only certain values are permitted (e.g., 0 and 1)IX. Network TopologiesTopologies – the structure (or “look”) of a network; 3 basic types: bus, ring, starProtocols – formal rules for communicationsNetwork ArchitecturesThe Internet’s TCP/IP – Transmission Control Protocol/Internet Protocol – the standard protocol for the InternetVoice Over IP – Internet telephony, replaces public-switched service