Transcript 6-3 - faraday

Networks and Networking
Chapter 6
Copyright Prentice-Hall, Inc. 2001
Get Wired!!
Surfing
Online Books
6-2
Monthly
Technology
Update
What is it
all about?
Computer networks simply enhance
the efficiency and effectiveness
of interactions between people,
whether they are knowledge workers or
Internet surfers.
6-3
Digital Convergence
DVDs
 Telephones
Becoming digitally
 Televisions
compatible!!
 Computers
 Newspapers
 College courses
 Textbooks on CD-ROM
 Banking/Finance

6-4
Connectivity
Seeking ways to interface, or connect, a
diverse set of hardware, software, and
databases.
6-5
Cooperative
Processing
E-commerce (electronic commerce)
 Intercompany Networking
 Electronic Data Interchange (EDI)
 Intranets
 Extranets

6-6
Data Communications
Data Communications
= Telecommunications
 Special hardware
transmits the digital
information between
computers

6-7
Data Communications
Hardware

6-8
Modem

Digital to Analog to Digital
 Internal & External
 Fax Modems
Network Interface Cards (NIC)
 Special Function
Communications Devices
 Routers (backbone hardware)

Data Communications
Messaging
Message is distributed among:
Host or Server computer - in control
Front-end Processor - establishes
handshake
Multiplexor - collects data from multiple
devices and sends it along
 Network Address

6-9
Communications
Protocols


6-10
Rules that govern the way data are transmitted
Communication between networks using
incompatible protocols (use of routers)
Serendipitous Surfing:
Government
Data Communications
Channel
6-11
The medium through which digital
information must pass to get from one
location in a computer
network to the next.
Also called the Line, Link or Pipe
Transmission Media
Transmission
Media
6-12
Wires & Wireless Media
 Channel Capacity (Bandwidth)
 Bits per Second (BPS) vs. Baud
 Types:

Twisted-Pair
Wire
Coaxial Cable
Fiber Optic Cable
High-Speed Wireless
Transmission Media
Twisted-Pair
Wire
6-13
Carries data as electrical signals
 POTS (plain old telephone service) 56 K bps
 ISDN - Line & Modem 128 K bps
 ADSL - Line & Modem 1.5 to 9 M bps

Downstream
rate
Upstream rate
Will compete with cable
Transmission Media
Coaxial
Cable
Carries data as electrical signals
 Hundreds of times faster than POTS
 100 times faster than ISDN
 Need a cable modem

6-14
Fiber Optic
Cable
Carries data as lasergenerated pulses of light
 Foundation transmission
medium for Internet
backbone
 Better for data security

Courtesy of International Business Machines Corporation
6-15
High-Speed
Wireless



Carries data via microwave or radio signals
Geosynchronous Orbit Satellites
Wireless Transceivers
6-16
Common
Carriers
AT&T, MCI, Sprint, etc.
 Private Line (or Leased Line)
 Switched Line (or Dial-Up Line)

6-17
Is it time to
GO yet?
6-18
Network
Topologies
6-19
Network Topology is a description of the
possible physical connections within a
network. It is a configuration of
hardware and it shows which pairs of
nodes can communicate.
Networks
Network
Topologies
6-20
Ring
Bus
Star
Networks
Client/Server
Computing

Centralized Computing

Trend to Decentralizing & Downsizing
Server
Computer
Client Computer
Proxy Server Computer
Front-end Applications
Back-end Applications
6-21
Network Line
Control
Communications Protocols (TCP/IP)
 Two Classifications:

Asynchronous
Transmission (low speed)
Synchronous Transmission (high speed)
6-22
Types of
Networks
WAN
Wide Area Network
Metropolitan Area Network
LAN
MAN
Local Net
Tiny Area Network
TAN
6-23
Sharing Resources
on a LAN
6-24
Applications software
 Links to mainframes
 Communications
capabilities
 I/O devices
 Storage devices
 Add-on boards

Local Area
Networks

LAN Access Methods

Token Access Method
 Ethernet

LAN Servers

File Server
 Print Server
 Communications Server
6-25
LAN
Software

Operating Systems
Peer
to Peer LANs
LANs with dedicated servers

Applications Software
Shared
software
Groupware

Networks on the Fly
6-26
End of Chapter 6
Interactive
Study Guide
Copyright Prentice-Hall, Inc. 2001