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Technical Infrastructure and Operational Practices 13% ~ 26 questions CATEGORIES OF COMPUTERS MAINFRAME MINICOMPUTER PERSONAL COMPUTER (PC) WORKSTATION SUPERCOMPUTER * MAINFRAME MIPS: Millions of Instructions per second LARGEST ENTERPRISE COMPUTER 5O MEGABYTES TO OVER ONE GIGABYTE RAM
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Technical Infrastructure and Operational Practices 13% ~ 26 questions
CATEGORIES OF COMPUTERS • MAINFRAME • MINICOMPUTER • PERSONAL COMPUTER (PC) • WORKSTATION • SUPERCOMPUTER *
MAINFRAME MIPS: Millions of Instructions per second • LARGEST ENTERPRISE COMPUTER • 5O MEGABYTES TO OVER ONE GIGABYTE RAM • COMMERCIAL, SCIENTIFIC, MILITARY APPLICATIONS • MASSIVE DATA • COMPLICATED COMPUTATIONS *
MINICOMPUTER • MIDDLE-RANGE • 10 MEGABYTES TO OVER ONE GIGABYTE RAM • UNIVERSITIES, FACTORIES, LABS • USED AS FRONT-END PROCESSOR FOR MAINFRAME *
MICROCOMPUTER • DESKTOP OR PORTABLE • 64 KILOBYTES TO OVER 128 MEGABYTES RAM • PERSONAL OR BUSINESS COMPUTERS • AFFORDABLE • MANY AVAILABLE COMPONENTS • CAN BE NETWORKED *
WORKSTATION • DESKTOP COMPUTER • POWERFUL GRAPHICS • EXTENSIVE MATH CAPABILITIES • MULTI-TASKING • USUALLY CONFIGURED TO SPECIAL FUNCTION (e.g.; CAD, ENGINEERING, GRAPHICS) *
CPU INPUT DEVICES SECONDARY STORAGE OUTPUT DEVICES COMMUNICATIONS DEVICES PRIMARY STORAGE COMPUTER COMPONENTS BUSES
H/W or S/W Acquisition • Why Purchase? • Immediate system availability • High quality • Low price • Available support
H/W or S/W Acquisition • Steps • Identifying the problem • Identifying potential vendors • Soliciting vendor information • Defining system requirements • Requesting vendor proposals
Steps • Reviewing proposals and screening vendors • Visiting sites • Selecting the vendor • Benchmarking • Negotiating a contract • Implementing the new system • Managing post-implementation support
Steps • Benchmarking • Codified comparison of performance measures between systems • Ensures adopted application satisfies the organization's minimum requirements • Learning from Experience
Software Overview • Computer program: sequences of instructions for the computer. • Documentation describes program functions to help people use it • Systems software coordinates the activities of hardware & programs. • Applications software helps users solve particular problems.
Operating Systems Activities • Perform common hardware functions • Provide a user interface • Provide hardware independence • Manage system memory • Manage processing • Control access to system resources • Manage files
Operating Systems Activities • Perform common hardware functions • Accept keyboard input • Store data on disks • Send data to output devices • Provide a user interface • Command-based interfaces • Graphical User Interfaces (GUIs)
Operating Systems Activities • Manage processing • Multitasking: more than one program can run at a time using a single processor • Time sharing: multiple users simultaneously using the resources of a single processor • Scalability: easy adaptation to more users or tasks • Manage files • Physical storage location • File permissions • File access • Control access to system resources • Protection against unauthorized access • Logins and passwords
Other Operating Systems • Network OS • Netware • Windows NT Server 4.0 • Windows 2000 Server • Enterprise Operating Systems • IBM’s OS/390 • HP’s MPE/iX (Multiprogramming Executive with integrated POSIX) • Consumer appliances OSs • Windows CE • Mobil Linux
Utility Programs • Virus scanner • File compressor • Screen saver
Database Models • The Hierarchical Model • Records are related hierarchically -- each category is a subcategory of the next level up • Disadvantages of hierarchical databases • To retrieve a record, a user must start at the root and navigate the hierarchy. • If a link is broken, the entire branch is lost. • Requires considerable data redundancy because child records can have only one parent
Database Models • The Network Model • Allows a record to be linked to more than one parent • Supports many-to-many (N:M) relationships • Advantage of the network model • Reduced data redundancy • Disadvantages of the network model • Complicated to build and maintain • Difficult to navigate
Database Models • The Relational Model • Consists of tables; links among entities are maintained with foreign keys • Advantages of relational databases • Same advantages of a network database without the complications. • Easier to conceptualize and maintain. • Virtually all DBMSs offered for microcomputers accommodate the relational model.
Normally employs relational data model Provide a user view Provide tools to create & modify the database Store & retrieve data Manipulate data Produce reports Database Management Systems (DBMSs)
Overview • Communication Flow • Synchronous communication • Asynchronous communication • Data Transmission Speeds • Measured in bits per second (bps) • Kilobits per second (kbps) • Megabits per second (Mbps) • Gigabits per second (Gbps)
Computer Networks • Telecommunications media • Telecommunications devices • Software • Hardware devices
Types of Media • Guided media • Twisted Pair • Coaxial Cable • Fiber-Optic Cable • Microwave Transmission • Unguided media • Infrared Transmission • Line of sight • Short distances • Microwave
Types of Devices • Modem • Analog signals: continuous • Digital signals: discrete • Modulation: translating digital data to analog • Demodulation: translating analog data to digital • Modems modulate & demodulate data
Carriers • Common carriers • Long distance carriers • Value-added carriers • Special purpose carriers • Additional services
Services • Line types • Switched • Dedicated • Private Branch Exchange (PBX) • Digital subscriber lines (DSL) • Integrated Services Digital Network (ISDN) • T1 Carrier
Network Concepts & Considerations • Network topology • Star • Bus • Ring • Network types • Local Area Networks • Wide Area Networks
User User HOST User User Network Topologies STAR
User User User User User User Network Topologies BUS
User User User User Network Topologies RING
Network Types • Logical Area Network (LAN) • Limited geographical area • Any topology possible • Network Interface Card (NIC) • Designs • Peer-to-peer • Client-server • Wide Area Network (WAN)
Communications Software • Error checking • Message formatting • Security • Network Operating System (NOS) • Network Management Software
7 layers of OSI/RM Model Please Do Not Touch Susan’s Pretty A**!!! Application Application Presentation Presentation Session Session Transport Transport Network Network Data Link Data Link Physical Physical
Use and Functioning of the Internet • Interconnected networks • NO control • NO management • NO charge • NO laws • NO ownership • NO………………………
How the Internet Works • Hosts • Routers forward packets to other networks • Internet Protocol Stack (TCP/IP) • Internet Protocol (IP) • Transport Control Protocol (TCP) • Backbones
How the Internet Works • Uniform Resource Locator (URL) • http://www.whitehouse.gov World Wide Web Domain category Hypertext transfer protocol Host Network Name
Internet Services • E-mail (Electronic mail) • Can include images, attachments, or HTML • Routed by gateways and routers • Telnet: remote login • FTP: file transfer • Chat rooms: allow interactive conversations • Instant Messaging: online, real-time communication over the Internet • Videoconferencing • Internet phone
The World Wide Web • An application running on the Internet • Allow multimedia presentation of information • Allow point and click • Allow graphical interface • Make the Internet much more user friendly
Web Software • Web browsers • Search engines • Keyword indexes: fast & broad • Subject indexes: focused searches • Tools • Word processors • HTML editor • HTML Template • Text editor • View your page • Add effects judiciously
Net Issues • Service bottlenecks • Firewalls • Privacy & security • Cookies • Cryptography • Encryption • Digital signature
Hardware Reviews • Review h/w acquisition plan • See if aligns with IS plan to identify any deficiencies • See if documentation for h/w and s/w specifications adequate • Review PC acquisition criteria to determine: • Written policy statements exists and have been communicated • Criteria, procedures and forms developed • Request supported by cost/benefit analysis
Hardware Reviews • Review change management controls • Verify IS mgmt developed and enforced change schedules • Verify operator documentation appropriately revise before implementation • Select sample of h/w changes that affected scheduling of IP and see if plans work • Assure h/w changes communicated to all
Operating System Reviews • Interview technical personnel • Review and approval process of option selection • Test procedures for s/w implementation • Review and approval procedures for test results • Documentation requirements • Review system s/w selection procedures • Address both IS and biz plans • Include IS processing and control requirements • Include overview of capabilities of s/w and control options