Transcript Networks and Communications

Networks and
Communications
Chapter 9
Introduction to IT
Basic Forms of Communication
Before technology????
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Newspaper
Radio
Television
Mail
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Pony Express (How long did it run?)
Next?????
Communication
Sending device
Communications channel
Receiving device
Computer Communications
Internet
Web
E-Mail
Instant Messaging
Chat Rooms
Newsgroups
Internet Telephony
FTP
Web Folders
Video Conferencing
Fax/Modem
Should Companies be Able to
Track your Online Habits?
Yes
No
Text Messaging
Why do you like it?
Why don’t you like it?
Picture Messages
Good uses?
Not so good uses?
What about cheating????
Public Internet Access Points
Campus
Libraries
Cyber Cafes
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Typical Fees
$1.50/hour to $10.00/hour
Global Positioning Systems
GPS
Where is it?
How is it use?
Collaboration
Net Meetings
Chat Rooms
Documents
Groupware
Software that helps groups meet
Also called workgroup computing
Example:
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E-groups
Voice Mail
Pick up voice mail from any location
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Using computer
E-mail
Voice over IP
Why Networks
Facilitate Communications
Transfer funds
Share software
Share data and information
Share hardware
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Printers
Scanners
Networks
LANs
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Local Area Networks
WANs
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Wide Area Networks
MANs
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Metropolitan Area Network
WLAN
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Wireless Local Area Networks
Network Architectures
Client/Server
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Server – Host Computer
Client – Other Computers
Peer to Peer
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Connects fewer than 10 computers
Computers have equal responsibilities
Equal capabilities
Sharing Hardware and data
Contain Network operating systems and software
Ideal for small businesses
Internet Peer to Peer
P2P
Also called a file
sharing network
Users share what is
on each individual
computer with each
other
Works only if both
computers are online
Network Topologies
Bus Network
Ring Network
Star Network
Intranets
Net within
Internal Network
Also Extranet
Open Systems
Interconnection
or
OSI Model
Network Standards
Ethernet
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No central device controls data transmission
If they try at the same time there is a conflict
and resolution
Token Ring
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Computers share or pass a token
Like passing on a “ticket”
Only one token per network-machine with
token can transmit
Network Standards (Cont)
TCP/IP
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Transmission Control Protocol/Internet
Protocol
Defines how messages are routed
Messages are turned into packets
HTTP, SMTP, POP all work with TCP/IP
802.11
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Specifies how wireless devices work together
Network Standards
BlueTooth
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Wireless Data Transfers
Don’t have to be aligned
IrDA
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Wireless Data Transfers
Must be aligned
RFID
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Radio Frequency Identification
Tags placed on animals or people
Network Communications
What is Wi-Fi???
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Allows many computers to be networked
wirelessly
WAP
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Wireless Application Protocol
Standard for wireless mobile devices
Smart Phones
PDAs
Telephone Communications
Dial-up Lines
Dedicated Lines
ISDN Lines
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Integrated Services Digital Network
Carries Telephone and digital info streams
DSL
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Digital Subscriber Line
Uses standard cooper wire to transfer info
Telephone Network
Telephone Communications
T-Carrier Lines
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T1, T2, T3, Etc.
Long distance digital lines
T3 = 28 times T1 speed
ATM
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Asynchronous Transfer Mode
High speed voice, data, video and multimedia
Signals
Communication Devices
Devices that send and receive data
Dial-up Modems
ISDN and DSL Modems
Cable Modems
Wireless Modems
Network Cards
Wireless Access points (Airports)
Routers
Home Networks
Ethernet
Powerline Cable Network
Phoneline Networks
Wireless Home Networks
Communications Channels
What is bandwidth?
Latency
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Time it takes a signal to travel from one
location to another on a network
Transmission Media
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Carries a signal
Examples?
Physical Transmission
Twisted Pair Cable
Coaxial Cable
Fiber-Optic Cable
Wireless Transmission
Infrared
Broadcast Radio
Cellular Radio
Microwaves
Communications Satellite