"Foundations of Information Systems in Business"
Telecommunications & Networks O’Brien Chapter Six Harris Spring 2009 Objectives Developments & trends Business value of Internet, intranet & extranet applications Components, functions & types of telecommunications networks Types of telecommunications network hardware, software, media & services Harris Spring 2009 ? ? Discussion ? ? It’s the Network, stupid! How has telecommunications changed over past 20 years? Past 10 years? Harris Spring 2009 Trends in Telecommunications Industry Trends Industry Trends Toward more competitive vendors, carriers, alliances & network services, accelerated by deregulation & growth of Internet & World Wide Web Technology Trends Toward extensive use of Internet, digital fiber-optic & wireless technologies to create high-speed local & global inter-networks for voice, data, images, audio & videocommunications Application Trends Toward pervasive use of Internet, enterprise intranets & inter-organizational extranets to e-business & e-commerce, enterprise collaboration & strategic advantage in local & global markets Network Concepts Network An interconnected chain, group or system Number of possible connections on a network is N * (N-1) Where N = number of nodes (points of connections on the network) Example, if there are 10 computers on a network, there are 10 * 9 = 90 possible connections Harris Spring 2009 Metcalfe’s Law The usefulness of a network equals the square of the number of users On a small network, a change in technology affects technology only On a large network like the Internet, a change in technology affects social, political & economic systems Harris Spring 2009 Telecommunications Telecommunications Exchange of information in any form (voice, data, text, images, audio, video) over networks Harris Spring 2009 Trends in Telecommunications Services available today… Full Service Spectrum Entertainment Information Transactions Communications •Broadcast TV •High-definition TV •Enhanced pay-per-view •Video-on-demand •Interactive TV •Interactive video games •Video catalog shopping •Distance learning •Desktop multimedia •Image networking •Transaction services •Internet access •Telecommuting •Videoconferences •Video telephony •Wireless Access •Cellular/PCS systems •POTS-Plain old telephone service Technology Trends •Internet Networking Technologies •Open Systems •Connectivity •Interoperability •Digital Network Technologies •Higher Transmission Speeds •Move Larger Amounts of Information •Greater Economy •Lower Error Rates than Analog Harris Spring 2009 No Barriers Overcome geographic barriers capture remote transactions Overcome time barriers 7x24 Overcome cost barriers technology cheap & pervasive Overcome structural barriers link for competitive advantage virtual Business Value of Telecommunication Networks Popular uses of the Internet Internet Adds Value to Businesses Inventory Management Systems Headquarters Suppliers The Internet Business Partners Customers Remote Offices Deriving Business Value Generate New Revenue Sources Develop New Markets and Channels Attract New Customers Reduce Costs of Doing Business Develop New Web-Based Products Increase Customer Loyalty and Retention Harris Spring 2009 Open Systems Information systems that use common standards for hardware, software, applications and networks Internet networking technologies are a common standard for open systems Connectivity: Ability of networked computers to easily access & communicate with each other and share information Interoperability: The ability of an open system to enable end user applications to be accomplished using different varieties of computer systems, software packages & databases provided by a variety of interconnected networks Middleware Any programming that serves to “glue together” two separate programs Harris Spring 2009 Digital Network Technologies Rapid change from analog to digital network technologies Analog: voice-oriented transmission, sound waves Digital: discrete pulse transmission Digital allows: Higher transmission speed Larger amounts of information Greater economy Lower error rates Multiple forms of communications on same circuit Harris Spring 2009 The Internet Over 46 million servers (2004) 710 – 945 million users (2004) No central computer system No governing body No one owns it Harris Spring 2009 Internet Service Provider ISP A company that specializes in providing easy access to the Internet For a monthly fee, you get software, user name, password and access ISPs are connect to one another through network access points Harris Spring 2009 Internet2 Next generation of the Internet High-performance network In use at 200 universities, scientific institutions, communications corporations Harris Spring 2009 GE Power Systems: Using the Internet •Creation of a Power Plant Entirely on the Internet •Holding Virtual Meetings •Blueprints Exchanged and Modified in Real Time on the Web •Customers Can Watch as Turbine is Built from Anywhere •20-30% Reduction in Time to Build Turbine •1-2% Increase in Turbine Output •30% Increase in Sales Revenue An Intranet A network inside an organization That uses Internet technologies (such as Web browsers and servers, TCP/IP protocols, HTML, etc.) To provide an Internet-like environment within the organization For information sharing, communications, collaboration & support of business processes Protected by security measures Can be accessed by authorized users through the Internet The Role of Intranets Communication and Collaboration Existing E-Mail, VoiceMail Systems Communicate and collaborate with e-mail, discussion forums, chat, and conferencing Internet Everyone Intranet Intranet Enterprise Information Portal Business Operations and Management Existing Databases and Enterprise Applications Secure, universal access to view and use corporate and external data Employees Web Publishing HTML, MS Office, XML, Java, and Other Document Types Author, publish, and share hypermedia documents F I R E W A L L Extranet Customers, Suppliers, and Partners Intranet Portal Management Existing Hardware and Networks Centrally administer clients, servers, security, directory, and traffic Extranet Network links that use Internet technologies To connect the Intranet of a business With the Intranets of its customers, suppliers or other business partners Harris Spring 2009 The Role of Extranets Connecting Enterprise to Consumers, Business Customers, Suppliers, and Other Business Partners Partners, Consultants, Contractors Consumers The Internetworked Enterprise Suppliers and Distributors Business Consumers Part II E-Commerce – revisit impact of networking on commerce Telecommunications Networks components types media hardware, including those black boxes software Harris Spring 2009 Case 2: Maryland and Colorado Serving their customers without using wires Earth Alert Emergency Management System in Maryland provides Devices to communicate warning to individuals before a disaster & Tools to collect timely information after a disaster Aurora Colorado Connects police & fire department vehicles via wire-less connections Harris Spring 2009 Case Study Questions 1. What is the business value of advanced mobile technologies to Maryland’s emergency management services? 2. In what other government services could GPS serve to provide business value? Give some examples. 3. Are there disadvantages or risks associated with the deployment of GPS systems to monitor the location of people? Explain. Harris Spring 2009 Telecommunications network Any arrangement where a sender transmits a message to a receiver over a channel consisting of some type of medium Harris Spring 2009 Components of Telecommunications Network 1 Telecommunications Processors 4 2 3 2 5 Telecommunications Software PCs, NCs, and Other Terminals Telecommunications Channels and Media Computers Harris Spring 2009 Wide Area Network (WAN) Telecommunications network that covers a large geographic area Source: Courtesy of Cisco Systems Inc. Typical Local Area Network Connect computers within a limited physical area such as an office, classroom, or building PC PC PC Shared Database and Software Packages Network Server Shared Printer PC PC Internetwork Processor to Other Networks Virtual Private Networks (VPN) A secure network that uses the Internet as its backbone but relies on firewalls, encryption & other security A pipe traveling through the Internet Harris Spring 2009 VPN Client/Server & Network Computing Networks are the central computing resource of the organization Thin clients: network computers & other clients provide a browser-based user interface Clients: End user personal computers or networked computers (thin clients) Interconnected by LANs Servers: manage networks Processing shared between clients & servers Harris Spring 2009 Client/Server Networks Functions of the Computer Systems Mainframe Large Servers Client Systems • Functions: Provide user interface, perform some/most processing on an application. Servers • Functions: Shared computation, application control, distributed databases. • Functions: Central database control, security, directory management, heavy-duty processing. Client-Server or Network Computing Where does the application run? Client Network Server Host System Superserver Central database control Heavy duty processing User Interface Application Processing Application Control Distributed Database NetPC Application Server DB Server Browser-based User Interface DBMS Web OS Application Software Peer-to-peer networks Networks that connect from one PC to another PC Common use is the downloading and trading of files Harris Spring 2009 Peer-to-Peer Network Telecommunications Media Twisted Pair Coaxial Cable Fiber Optics Terrestrial Microwave Communication Satellites Cellular Technologies Wireless LAN Wireless Technologies Terrestrial microwave Earthbound microwave systems that transmit high-speed radio signals in a line-of-sight path Between relay systems spaced approximately 30-miles apart Communications satellites Satellite serves as relay stations for communications signals Uses microwave radio signals Harris Spring 2009 Wireless Technologies Cellular and PCS telephone and pager systems Divide the geographic area into small areas or cells Each cell has transmitter or radio relay antenna to send message from one cell to another Wireless LANs Radio signals within an office or building Connect PCs to networks Bluetooth Short-range wireless technology To connect PC to peripherals such as printer Harris Spring 2009 Wireless Web Connect portable communications devices to the Internet Wireless Application Protocol (WAP) Problem of “The Last Mile” Network providers use fiber optic to provide backbone But houses are connected to the backbone via twisted-pair Cannot get the benefit of the faster, better technology Harris Spring 2009 Telecommunications Processors & Software Modems Multiplexers Internetwork Processors Switches Routers Hubs Gateways Fire walls Network Operating System Telecomm Monitor Middleware Network Management Software Connecting Networks Those black boxes Hub all messages pass thru the hub Bridge only ―needed‖ msgs pass thru bridge two LANS using same protocol Harris Spring 2009 Connecting Networks Switch more than 2 LANs or segments same protocol Router/Gateway two LANS using any protocols only needed messages pass thru Harris Spring 2009 Typical Internet Connection Network Interface Card NIC Hub NIC Ethernet Switch Router Frame Relay Switch Router Corporate Local Area Network Core Router ATM Switch Frame Remote Router Relay Access Switch Device Internet Provider ATM Switch Internet Backbone Internet Provider Modem Private Home Network Topologies Topologies or Network Structures Star Ring Bus Mesh Client/Server May Use Any Combination Network Topologies Used to be just point to point Network Architecture and Protocols TCP/IP Application or Process Layer The OSI Model Application Layer Presentation Layer Session Layer Transport Layer Network Layer Data Link Layer Physical Layer • Provides communications services for end user applications • Provides appropriate data transmission formats and codes • Supports the accomplishment of telecommunications sessions • Supports the organization and transfer of data between nodes in the network • Provides appropriate routing by establishing connections among network links • Supports error-free organization and transmission of data in the network • Provides physical transmission of data on the telecommunications media in the network Host-to-Host Transport Layer Internet Protocol (IP) Network Interface Physical Layer Comparing modem & other technologies Bandwidth Alternatives Narrow Band Medium Band Broadband Switching Alternatives Internet Telephony Using an Internet connection to pass voice data using IP Voice over IP (VoIP) Skips standard long-distance phone charges Harris Spring 2009 Case 3: Voice Over IP is the Real Thing VoIP works by Digitizing a voice signal, Chopping it into packets & Sending them over a company’s network or the Internet Packets are reassembled at the destination Minnesota Department of Labor has cut its monthly phone bill in half Harris Spring 2009 Case Study Questions 1. What are the main benefits that can be gained by companies that switch to VoIP systems? 2. What are some of the major cost factors that may limit a positive rate of return from investments in VoIP projects? 3. Should more companies switch to VoIP systems? Visit the websites of Avaya and Cisco Systems to view their VoIP news, products & services to help you answer. Harris Spring 2009 Skype http://www.skype.com/ Make calls from your computer — free to other people on Skype and cheap to landlines and cell phones around the world. Harris Spring 2009 Harris Spring 2009