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Technology In Action Chapter 7
Chapter 6 Summary Questions
• How can I determine whether I should
upgrade my existing computer or buy a
new one?
• What does the CPU do and how can I
evaluate its performance?
• How does memory work and how can I
evaluate how much memory I need?
• What are the computer’s main storage
devices and how can I evaluate whether
they match my needs?
© 2006 Prentice-Hall, Inc.
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Technology In Action Chapter 7
Chapter 6 Summary Questions
• What components affect the output of
video and how can I evaluate whether
they are meeting my needs?
• What components affect the quality of
sound and how can I evaluate whether
they are meeting my needs?
© 2006 Prentice-Hall, Inc.
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Technology In Action Chapter 7
Technology In Action
Chapter 7
Networking and Security: Connecting
Computers and Keeping Them Safe from
Hackers and Viruses
© 2006 Prentice-Hall, Inc.
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Technology In Action Chapter 7
Topics
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Networking fundamentals
Network architecture
Network components
Peer-to-peer networks
Computer threats
Computer safeguards
Computer viruses
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Technology In Action Chapter 7
Networking Fundamentals
• Computer network:
– Two or more computers connected together
– Nodes
• Benefits of a network:
– Sharing resources
– Transferring files
– Sharing internet
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Technology In Action Chapter 7
Network Architecture
• Network designs:
– Locally controlled:
 Peer-to-peer (P2P)
– Centrally controlled:
 Client/server
Peer-to-peer
Client/
server
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Technology In Action Chapter 7
Peer-to-Peer Networks
• Nodes communicate
with each other:
– Peers
• Share peripheral
devices:
– Printers
– Scanners
• Home and small office
networks
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Technology In Action Chapter 7
Client/Server Networks
• Client computers:
– Users
• Server computers:
– Provide resources to clients
– Central control unit
• Internet
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Technology In Action Chapter 7
LANs and WANs
• Local area network (LAN):
– Nodes are within a small geographic region:
 Homes
 Schools
 Small businesses
• Wide area network (WAN):
– LANs connected over long distances:
 A few miles to thousands of miles
 Use telecommunications lines
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Technology In Action Chapter 7
Network Components
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Transmission media
Network adapters
Navigation devices
Network software
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Technology In Action Chapter 7
Transmission Media
• Provides communications channel between
nodes
• Forms of media:
– Telephone wire:
 Twisted pair
– Coaxial cable
– Fiber-optic cable
– Radio waves:
 Wireless
• Bandwidth:
– Data transfer rate, throughput
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Technology In Action Chapter 7
Network Adapters
• Devices connected to or installed in nodes:
– Network interface cards (NIC)
– External network adapter
• Enable communication between nodes
NIC
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External
adapter
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Technology In Action Chapter 7
Network Navigation Devices
• Devices that help make data flow possible
– Packets
• Routers:
– Route data between networks
• Hubs:
– Receive data and retransmit it to nodes on the
network
Router
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Hub
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Technology In Action Chapter 7
Networking Software
• Software needed:
– Peer-to-peer:
 Operating systems that support networking
 Windows
 Mac OS
– Client/server:
 Network operating system (NOS) software
 Windows XP Professional
 Windows Server 2003
 Novell Netware
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Technology In Action Chapter 7
Types of Peer-to-Peer Networks
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Power line
Phone line
Ethernet
Wireless
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Technology In Action Chapter 7
Power Line Networks
• Computers are connected to a house’s
electrical wiring to create a network
• Power line network adapter is used to
connect nodes to electrical outlets
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Technology In Action Chapter 7
Phone Line Networks
• Computers are connected
to a house’s telephone
wiring to create a network
• Home phone line network
adapter is used to
connect nodes to phone
jacks
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Technology In Action Chapter 7
Ethernet Networks
• Computers are connected to each other
using unshielded twisted pair cable (UTP)
– Cat 5 (100Mbps), Cat 5E(200Mbps), Cat 6(1Gbps)
• Ethernet network adapters are used to
connect nodes
NIC card
– NIC
– PC card
– USB adapter
© 2006 Prentice-Hall, Inc.
PC
card
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Technology In Action Chapter 7
Ethernet Hubs
• Keep track of data packets
• Amplify and retransmit signals
• Keep the network running efficiently
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Technology In Action Chapter 7
Ethernet Routers
• Route packets of data between networks
• Router needed to send data between the
network and the Internet
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Technology In Action Chapter 7
Wireless Networks
• Use radio waves to connect nodes
• 802.11 standard (Wi-Fi: Wireless Fidelity)
– 802.11b (11Mbps), 802.11g(54Mbps)
• Basically an Ethernet network that uses
radio waves instead of wires
• Each node requires a wireless network
adapter:
– Transceiver
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Technology In Action Chapter 7
Limitation
• Maximum range: 250 feet
• Interference with other wireless devices
• Obstacles between wireless nodes
– Wall
– Large metal objects
• Wireless DSL/cable router
© 2006 Prentice-Hall, Inc.
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Technology In Action Chapter 7
Choosing a Peer-to-Peer Network
• Things to consider:
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Existing wiring
Wireless or wired
Speed of the network
Cost of the network
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Technology In Action Chapter 7
Comparison
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Technology In Action Chapter 7
Configuring Software for a Home
Network
• Windows operating system:
– Windows XP:
 Network setup wizard
– Windows ME:
 Network setup wizard
– Windows 98:
 Configure manually
© 2006 Prentice-Hall, Inc.
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Technology In Action Chapter 7
Computer Threats
• Cyber-crime
• Hackers:
– Who they are
– What they do
– How they gain access
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Technology In Action Chapter 7
Cyber-crimes and Cyber-criminals
• Cyber-crimes are criminal
acts conducted through
the use of a computer:
– Fraud
– Identity theft
• Cyber-criminals are
individuals who use a
computer to commit a
crime
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Technology In Action Chapter 7
Hackers
• Anyone who unlawfully accesses a
computer system
• Types of hackers:
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Cracker
White-hat
Black-hat
Script kiddies
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Technology In Action Chapter 7
What Hackers Do
• Steal information from computers:
– Credit card numbers
– Bank account numbers
• Internet packet sniffing
• Commit identity theft
• Create widespread computer attacks:
– Backdoor programs (Trojan horse)
– Zombies
• Denial of service attacks (DoS)
• Distributed denial of service (DDoS) attacks
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Technology In Action Chapter 7
How Hackers Gain Access
• Direct access:
– Hacking software
• Indirect access:
– Internet connection
– Logical ports
 HTTP: 80
 SMTP: 25
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Technology In Action Chapter 7
Computer Safeguards
• Firewalls
• Viruses and antivirus software
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Technology In Action Chapter 7
Firewalls
• Software programs or hardware designed
to close logical ports to invaders
• Types of firewalls:
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Norton Personal Firewall
McAfee Firewall
Zone Alarm
BlackICE PC Protection
Network routers
© 2006 Prentice-Hall, Inc.
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Technology In Action Chapter 7
Is your computer secure?
• Gibson Research Corporation
– www.grc.com
– ShieldsUP
– LeakTest
• Qualys
– http://browsercheck.qualys.com
© 2006 Prentice-Hall, Inc.
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Technology In Action Chapter 7
Chapter 7 Summary Questions
• What is a network and what are the
advantages of setting up one?
• What is the difference between a
client/server network and a peer-to-peer
network?
• What are the main components of every
network?
• What are the most common home
networks?
© 2006 Prentice-Hall, Inc.
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Technology In Action Chapter 7
Chapter 7 Summary Questions
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What are power line networks?
What are phone line networks?
What are Ethernet networks?
What are wireless networks?
How can hackers attack a network and
what harm can they cause?
• What is a firewall and how does it keep
my computer safe from hackers?
© 2006 Prentice-Hall, Inc.
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