Management Information Systems INFO 6240 MBA Programme Management Center IIUM

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Management Information Systems INFO 6240MBA
ProgrammeManagement Center / IIUM
E

• Ahmed M. Zeki
• amzeki_at_iiu.edu.my
• Mar - May 2007

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INTRODUCTION

• Computer network two or more computers
  connected so that they can communicate with each
  other and share information, software, peripheral
  devices, and/or processing power

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Basic Principles of Networks

• These four principles apply to all networks,
  large and small
• Each computer must have a network interface to
  provide a doorway for information
• The network needs at least one connecting device
• The network must have communications media as
  pathways for information
• Each computer must have a network operating system

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PEER-TO-PEER HOME NETWORK

• Peer-to-peer network a network in which a small
  number of computers share hardware, software
  and/or information
• A small peer-to-peer network can be wired with
  Ethernet cable or it can be wireless

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Home Network Components

• To set up a small home network youll need
• An Ethernet network card in each computer
• A home router as a connecting device
• Cables as the communications media
• Windows as the network operating system

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Network Cards

• Network interface card (NIC) an expansion card
  or PC Card that connects your computer to a
  network
• Ethernet card the most common type of (NIC)

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Connecting Devices Hubs

• Hub a device that connects computers into a
  network and repeats all transmissions to every
  connected computer
• Only one computer can transmit at a time
• All computers see every message
• Can have collisions when two computers try to
  transmit at the same time

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Connecting Devices Switches

• Switch a device that connects multiple
  computers into a network in which multiple
  communications links can be in operation
  simultaneously

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Connecting Devices Routers

• Router a device that connects computers into a
  network and separates it from any other network
  its connected to
• Allows multiple simultaneous communications
  links also acts as a firewall,

which is hardware and/or software that protects a
computer or network from intruders
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Wired Transmission Media

• Cat 5 (Category 5) cable better constructed
  version of phone twisted-pair cable
• Each end has an RJ-45 connector (looks like a
  phone connector, but is bigger)

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Wireless Transmission Media

• Wireless network access point (wireless access
  point) device that allows computers to access a
  network using radio waves

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Wireless Standards

• Wifi (wireless fidelity or IEEE 802.11a, b or g)
  a standard for transmitting information in the
  form of radio waves over distances up to about
  300 feet
• Used for wireless connection to a network
• Bluetooth a standard for transmitting
  information over distances of up to 30 feet
• Used for devices (synch PDAs and cell phones)

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Typical Home Network
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INTERNET ACCESS

• Five ways
• Phone line and dial-up modem
• Phone line and DSL modem
• Cable TV line and cable modem
• Satellite dish and satellite modem
• Wireless Internet provider with WiFi card

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INTERNET ACCESS

• Broadband high-capacity telecommunications
  pipeline capable of providing high-speed Internet
  service
• All Internet access methods on the previous slide
  are broadband except the dial-up modem type

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Telephone or Dial-Up Connection

• Telephone modem (modem) connects your computer
  to your phone line so that you can access another
  computer or network

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Pros and Cons of Dial-Up

• Advantages
• Cheaper than broadband
• Less vulnerable to intruders since its not
  always on
• Disadvantages
• Slow
• Cant use phone line to talk while youre online

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Digital Subscriber Line

• Digital Subscriber Line (DSL) high-speed
  Internet connection using phone lines, which
  allows you to use your phone for voice
  communications at the same time

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Pros and Cons of DSL

• Advantages
• High speed access
• DSL guarantees a certain access speed
• Disadvantages
• you have to live close to a CO (Central Office)
• DSL is an always-on connection

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Cable Modem

• Cable modem device that uses your TV cable to
  deliver an Internet connection

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Pros and Cons of Cable Modem

• Advantages
• High speed access
• Available wherever cable TV can be had
• Disadvantages
• Speed degrades as number of people using it
  increases
• Always-on connection

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Internet over Satellite

• Satellite modem modem that allows you to get
  Internet access from your satellite dish

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Pros and Cons of Satellite Modem

• Advantages
• High speed
• Allows Internet access in remote areas
• Disadvantages
• Need special dish
• Download about 10 times faster than upload

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T1 and DS3 Business Lines

• T1 and DS3 developed by phone companies to carry
  many long-distance voice conversations
• T1 runs up to about 1.5 Mbps
• DS3 runs up to about 45 Mbps
• Can carry both voice and network over the same
  lines

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Wireless Internet

• Wireless Internet service provider (wireless ISP)
  does the same job as a standard Internet
  services except that you dont need wires

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Frame Relay and ATM Business Services

• Frame Relay and ATM are used to connect many
  branch offices to the main office
• Use virtual circuits to simulate having a line
  from every office to every other office

Virtual Circuits
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Comparison of Connection Types

• Telephone modem
• Inexpensive and available anywhere there's a
  phone line
• - Slow, and ties up the line for voice calls too
• DSL
• Higher-speed connection, doesn't tie up the
  phone line for voice calls, and can be left on
  all the time
• - Not available in all areas or on all lines

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Comparison of Connection Types

• Cable modem
• Higher-speed connection, doesn't use the phone
  line at all, and always-on
• - Connection shared with the neighborhood, so
  speed may vary
• Satellite modem
• Available in remote locations where DSL and
  cable aren't
• - High cost

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Comparison of Connection Types

• T1 and DS3
• High-speed to very-high-speed connections, can
  transmit both voice and data
• - High cost that may be mileage-dependent
• Frame relay and ATM
• Use virtual circuits to simulate more
  inter-office connections than are physically
  present
• - High cost normally affordable only by mid- to
  large-scale enterprises

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Voice Over IP

• Voice over IP allows you to send voice
  communications over the Internet and avoid
  long-distance toll charges
• No long-distance calling cost

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Personal Digital Assistant (PDA)

• Personal digital assistant (PDA) small
  hand-held computer that allows you surf the Web
  and perform certain personal organization tasks
• Two types
• Palms and Handsprings run on Palm Operating
  System
• Pocket PCs run on Pocket PC OS

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BUSINESS NETWORKS

• Client/server network - a network in which one or
  more computers are servers and provide services
  to the other computers, called clients

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Client/Server A Business View

• Client/server networks differ according to
• Where the processing for the presentation of
  information occurs
• Where the processing of logic or business rules
  occurs
• Where the data management component (DBMS) and
  information (database) are located

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Client/Server Implementation Model 5
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The Five Models of Client/Server

• Distributed Presentation
• The server handles almost all functions,
  including a major portion of the presentation
• Remote Presentation
• The client handles all presentation functions

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The Five Models of Client/Server

• Distributed Logic
• The server handles all data management and the
  client handles all presentation formatting, and
  the logic processing is shared

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The Five Models of Client/Server

• Remote Data Management
• The server handles data management only, and the
  client processes business rules and formats the
  presentation of results
• Distributed Data Management
• The client handles all presentation formatting
  and business rule processing, and both the server
  and client share data management duties

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The Five Models of Client/Server
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Client/Server A Physical View

• Communications protocol (protocol) a set of
  rules that every computer follows to transfer
  information

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LANs, MANs, WANs, WLANs, AND COMMUNICATIONS MEDIA

• Networks can be classified by size
• Local area network (LAN) - covers a limited
  geographic distance, such as an office, building,
  or a group of buildings in close proximity to
  each other
• Municipal (or metropolitan) area network (MAN) -
  covers a metropolitan area

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Networks by Size

• Wide area network (WAN) covers a large
  geographic distance, such as a state, a country,
  or even the entire world
• Wireless local area network (WLAN or LAWN) a
  local area network that uses radio waves rather
  than wires to transmit information

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Telecommunications Media The Paths That Carry
Information

• Communications media - the paths, or physical
  channels, in a network over which information
  travels
• Wired communications media - transmit information
  over a closed, connected path
• Wireless communications media - transmit
  information through the air

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Bandwidth

• Bandwidth capacity of the communications
  medium, refers to the amount of information that
  it can transfer in a given amount of time

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Wired Communications Media

• Twisted-pair cable
• Comes in several varieties Cat 5 is usual for
  networks
• Coaxial cable (coax) a central wire surrounded
  by insulation, a metallic shield, and a final
  covering of insulating material

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Wired Communications Media

• Optical fiber uses a very thin glass or plastic
  fiber through which pulses of light travel

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Wireless Communications Media

• Infrared, IR or IrDA (infrared data association)
  uses red light to send and receive information
• Microwave a type of radio transmission
• Repeater a device that receives a radio signal,
  strengthens it, and sends it on

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Wireless Communications Media

• Communications satellite microwave repeater in
  space

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COMMUNICATIONS SERVICE PROVIDERS

• Network ownership determines
• Rights to the network
• Cost
• Availability
• Services provided
• Speed
• security

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Types of Network Ownership

• Communications service provider third party
  that furnishes the conduit for information
• Public network a network on which your
  organization competes for time with others

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Types of Network Ownership

• Private network consists of the communications
  media that your organizations owns or exclusively
  leases to connect networks or network components

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Types of Network Ownership

• Virtual private network (VPN) uses software to
  establish a secure channel on the Internet for
  transmitting information
• International virtual private network
  (international VPN) to transmit information
  over a network that extends beyond national
  borders

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Key Considerations for Communications Media

• Capacity
• Reliability
• Cost
• Distance
• Mobility

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NETWORK SECURITY

• The four principles of network security are
• Confidentiality
• Authenticity
• Integrity
• Availability

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NETWORK SECURITY

• Confidentiality information can be obtained
  only by those authorized to access it
• Bank statements, credit reports, employee
  evaluations
• Threatened by capture of network transmissions
  and easily-guessed passwords

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NETWORK SECURITY

• Authenticity information really comes from the
  source it claims to come from
• Military orders, medical diagnoses, stockbroker
  directions
• Threatened by fraudulent e-mails and misspellings
  of popular Web site names

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NETWORK SECURITY

• Integrity information has not been altered
• Bank balance, corporate Web site, prescriptions,
  credit card charges
• Threatened by forged network transmissions and
  faulty server software

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NETWORK SECURITY

• Availability a service or resource is available
  when it's supposed to be
• Mail-order Web site, corporate e-mail server
• Threatened by network failures, faulty server
  software, and high volumes of malicious network
  traffic

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Firewalls Intrusion Detection Systems

• Firewall protects a computer from intruders
• Intrusion Detection System (IDS) watches for
  and reports intrusion attempts

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Encryption

• Encryption scrambles data so you can't read it
  without having the decryption key
• Virtual Private Network (VPN) encrypts all
  network transmissions between two endpoints to
  protect confidentiality and integrity of data

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Malware

• Malware software designed to harm your computer
  or security
• Virus software written with malicious intent to
  cause annoyance or damage
• Worm spreads itself from computer to computer
  via e-mail and other network traffic
• Spyware collects information about you and
  reports it to someone else without your
  permission

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CLIENT/SERVER SOFTWARE MODEL

• Client/server network a network in which one or
  more computers are servers and provide services
  to the other computers, called clients