Download Networks and Networking

Computers
© 2005 Prentice-Hall, Inc.
Slide 1
Computers
Chapter 6
Networks and Networking
© 2005 Prentice-Hall, Inc.
Slide 2
Computers
Chapter 6 – Networks and Networking
Objectives
 Apply the concept of connectivity to your life
 Understand data communications hardware
 Identify data transmissions services
Understand the various network topologies
Recognize the potential of home networking
© 2005 Prentice-Hall, Inc.
Slide 3
Computers
Networks and Networking
Our Wired World
 Connectivity – the degree to which
software, hardware, and databases are
functionally linked
© 2005 Prentice-Hall, Inc.
Slide 4
Computers
Networks and Networking
Our Wired World
 Cooperative processing
 Intracompany networking – cooperation
within the company
 Intercompany networking – cooperation
with other companies and customers
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Slide 5
Computers
Networks and Networking
Our Wired World
 Intranet –internal network based on
Internet technology
 Extranet – an extension of an
intranet, partially available to customers
and suppliers
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Slide 6
Computers
Networks and Networking
Our Wired World
 Virtual Private Network (VPN) –
network transmissions are tunneled
through the Internet
 Tunneling – one network uses
another to send data
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Slide 7
Computers
Networks and Networking
Data Communications Hardware
Data communications or
telecommunications – distribution of
data
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Computers
Networks and Networking
Data Communications Hardware
 Server computers – central computers
that control the network
 Client computers – computers, linked
to a server, that create the network
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Computers
Networks and Networking
Data Communications Hardware
 Proxy server computers – handle
some requests, hand others to the actual
server computers
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Computers
Networks and Networking
Data Communications Hardware
 Telephone-link modem – converts
analog signals to digital and digital
signals to analog
 Analog – voice communication, such
as over a telephone line
Digital – 1’s and 0’s used to represent
data in a computer
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Slide 11
Computers
Networks and Networking
Data Communications Hardware
 Modem
Internal
External
Voice/data/fax modem
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Slide 12
Computers
Networks and Networking
Data Communications Hardware
 Cable modem – provides Internet
access via cable television lines
 DSL (Digital Subscriber Line) –
Internet access via special line provided
by a telephone company
 Satellite modem – Internet access via
communications satellite
© 2005 Prentice-Hall, Inc.
Slide 13
Computers
Networks and Networking
Data Communications Hardware
 Network interface card (NIC) – also
called network card and network
adapter
Needed to connect a personal computer
to a network
Ethernet – de facto standard
© 2005 Prentice-Hall, Inc.
Slide 14
Computers
Networks and Networking
Data Communications Hardware
 Gateway – allows for communication
between networks using different
protocols
 Router – routes messages to the
appropriate destination
Gateway router – both functions in
one device
© 2005 Prentice-Hall, Inc.
Slide 15
Computers
Networks and Networking
Data Communications Hardware
 Message
Source – device that sends the message
Destination – device that receives the
message
Handshaking – router establishes the
connection between the source and the
destination
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Slide 16
Computers
Networks and Networking
Data Communications Hardware
 Network address – assigned to each
computer on a network; used to send
messages to the appropriate destination
 Backbone – the routers, gateways,
and other equipment that link the
computers of the network
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Slide 17
Computers
Networks and Networking
Data Communications Hardware
 Hub – expands the number of nodes
on a network
Half-duplex – data can only be sent in
one direction at a time
 Switch – acts like a hub for a local
area network (LAN)
Full-duplex – data can be sent in both
directions at once
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Slide 18
Computers
Networks and Networking
Data Communications Hardware
 Terminals
Video Display Terminal – input/output
device
Thin client – smart terminal, capable of
some processing
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Computers
Networks and Networking
Data Communications Hardware
 Telephony – integration of telephones
and computers
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Slide 20
Computers
Networks and Networking
Data Communications Hardware
Automatic Teller Machine (ATM) –
used in banking
 Point-of-Sale (POS) terminals – used
in retail
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Slide 21
Computers
Networks and Networking
The Data Communications Channel
Communications channel – media a
message must pass through on a
network
Line
Link
Pipe
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Slide 22
Computers
Networks and Networking
The Data Communications Channel
Transmission media
Measured in bits per second (bps)
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Computers
Networks and Networking
The Data Communications Channel
Twisted-pair wire
POTS (plain old telephone services)
Digital Subscriber Line (DSL)
Cat5 cabling – uses four twisted pairs
of wire; speeds of up to 100 M bps
Cat5e cabling – speeds of up to 1 G
bps
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Slide 24
Computers
Networks and Networking
The Data Communications Channel
Coaxial cable – high capacity channel,
capable of speeds up to 10 M bps
Fiber optic cable – carries data as
electrical signals
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Slide 25
Computers
Networks and Networking
The Data Communications Channel
Wireless communication
 Microwave signal – sent from one
transmitter to another
Radio frequency (RF) signal – line-ofsight
© 2005 Prentice-Hall, Inc.
Slide 26
Computers
Networks and Networking
The Data Communications Channel
Communications satellite – repeater
for microwave transmissions in
geosynchronous orbit
Geosynchronous orbit – 22,300 miles
above the earth
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Slide 27
Computers
Networks and Networking
The Data Communications Channel
Wireless networks
Access points – college campuses, coffee
shops, local area networks
Wi-Fi – approximately 300 foot range
Bluetooth – approximately 30 foot
range
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Slide 28
Computers
Networks and Networking
The Data Communications Channel
Wireless Application Protocol (WAP)
Internet access standard for wireless
devices such as cell phones
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Slide 29
Computers
Networks and Networking
The Data Communications Channel
Future of wireless
Multichannel Multipoint Distribution
Service (MMDS)
Local Multipoint Distribution Service
(LMDS)
© 2005 Prentice-Hall, Inc.
Slide 30
Computers
Networks and Networking
The Data Communications Channel
Common carriers
Examples: AT&T, Sprint, MCI
Private line (leased line) – charge based
on channel capacity and distance
Switched line (dialup line) – time and
distance charge
© 2005 Prentice-Hall, Inc.
Slide 31
Computers
Networks and Networking
The Data Communications Channel
Communications protocols – rules
established to govern the way data are
transmitted in a computer network
Asynchronous transmission – data sent on an
as-needed basis
Synchronous transmission – source and
destination operate in timed synchronization
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Slide 32
Computers
Networks and Networking
Networks
Node – terminal, PC, or any device
connected to a network
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Slide 33
Computers
Networks and Networking
Networks
Types of Networks
Personal Area Network (PAN) –
connects cell phones or other electronics to
the network
Local Area Network (LAN) – nodes are
in close proximity
© 2005 Prentice-Hall, Inc.
Slide 34
Computers
Networks and Networking
Networks
Types of Networks
Metropolitan Area Network (MAN) –
network that encompasses a city
Wide Area Network (WAN) – nodes of
the network are geographically distant
© 2005 Prentice-Hall, Inc.
Slide 35
Computers
Networks and Networking
Networks
LAN resources that can be shared
 Applications software
 Links to other LANs
 Communications capabilities
 I/O devices
 Storage devices
 Add-on boards
© 2005 Prentice-Hall, Inc.
Slide 36
Computers
Networks and Networking
Networks
LAN access methods
 Network Access Method – rule that a
network uses to determine priorities
Logical topology
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Slide 37
Computers
Networks and Networking
Networks
Ethernet – widely used network
access method; uses Carrier Sense
Multiple Access/Collision Detection
(CSMA/CD protocol)
Token Access Method
© 2005 Prentice-Hall, Inc.
Slide 38
Computers
Networks and Networking
Networks
Servers
File server – stores programs and data to
be shared via the network
Print server – handles print jobs
Communication server – provides access
to other networks
LAN server – PC designed to be server
© 2005 Prentice-Hall, Inc.
Slide 39
Computers
Networks and Networking
Networks
LAN software
Network operating system (NOS)
Peer-to-peer (P2P)
Dedicated server
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Slide 40
Computers
Networks and Networking
Networks
LAN software
Peer-to-peer LAN – all PCs are equal in
the network
Client/server LAN – NOS resides on the
server computer
© 2005 Prentice-Hall, Inc.
Slide 41
Computers
Networks and Networking
Networks
Application software for LANs
Client/server LAN applications software
Front-end application software – user
interface and applications software
processed locally
Back-end application software – handles
tasks associated with storage and
maintenance of databases
© 2005 Prentice-Hall, Inc.
Slide 42
Computers
Networks and Networking
Networks
Application software for LANs
Download (server-to-client)
Upload (client-to-server)
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Slide 43
Computers
Networks and Networking
Networks
Shared applications software
Groupware – allows a group of people to
work on a project
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Slide 44
Computers
Networks and Networking
Networks
Shared applications software
Electronic mail (e-mail)
Instant messaging
Calendar and scheduling
Brainstorming
Shared whiteboarding
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Slide 45
Computers
Networks and Networking
Networks
Shared applications software
Setting priorities
Electronic conferencing
Electronic forms
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Slide 46
Computers
Networks and Networking
Networks
Home network – small LAN in the
home
© 2005 Prentice-Hall, Inc.
Slide 47
Computers
Networks and Networking
Networks
Home network technologies
Wired
Wireless
Home phoneline networking (HomePNA
or HPNA) – uses existing telephone lines
to create the network
HomePlug – uses electrical lines to
connect computers in the network
© 2005 Prentice-Hall, Inc.
Slide 48
Computers
Networks and Networking
Networks
Home network decisions
How many computers? Where will they
be placed?
How much do you want to spend?
What is your networking expertise?
Do you expect the network to grow?
What applications do you want to run?
© 2005 Prentice-Hall, Inc.
Slide 49
Computers
Networks and Networking
Networks
Steps to installing a home network
Install network interface cards
Set up communication hardware
Link PCs to router/hub/switch
Set up network software
Identify files/printers to be shared
Set up Internet connection sharing
© 2005 Prentice-Hall, Inc.
Slide 50
Computers
Chapter 6 – Networks and Networking
Lesson Summary
•
•
•
•
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Apply the concept of connectivity to
your life
Understand data communications
hardware
Identify data transmission services
Understand the various network
topologies
Recognize the potential of home
networking
© 2005 Prentice-Hall, Inc.
Slide 51