Introduction to MIS1 Networks and Telecommunications.
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Transcript of Introduction to MIS1 Networks and Telecommunications.
Introduction to MIS 1
Introduction to MIS
Networks and Telecommunications
Introduction to MIS 2
NetworksTeamworkCommunicationSchedulingSharing
Internet
SuppliersCustomersBanks
Internal
External
Introduction to MIS 3
Outline Introduction
Sharing Data Sharing Hardware Sharing Software
Components of a Network Computers Media Connection Devices Software
Network Structure Shared Media Switched
Standards The Internet
How the Internet Works Internet 2 Mobile Commerce
Global Telecommunications Technical Problems Political Complications Cultural Issues Comment
Cases: Specialty Retail Appendix: Creating Web
Pages
Introduction to MIS 4
Sharing Data: Transactions
Database ManagementSystem and Web Server
Internet
Introduction to MIS 5
Team Document
File Server and Database
Data and Tools
Report andComments
Sharing Data: Decisions & Searches Decisions & searches Teamwork & joint authorship
Introduction to MIS 6
Sharing Data: E-mail
Internet
1. User creates e-mail message.
2. Message transferred to account on server.
3. Transferred via the Internet to the destination account.
4. Message received when user checks e-mail.
Introduction to MIS 7
Sharing Data: Calendars
8:00 Mgt meeting
8:30 (open)
9:00 Staff meeting
9:30 Staff meeting
10:00 new meeting
Introduction to MIS 8
Hardware Sharing Printers Storage Processors
Files are transferred from workstations to the server. Software automatically copies files to tapes. LAN administrator can restore files if needed.
Corporate orexternal computeraccess
Server
Shared Printer
Workstations
tape drive(backup)
Introduction to MIS 9
Voice
Computer
Sent as packets: 1 2 3 4 5
Sent as packets: A B C D E
ChicagoNew York
DallasAtlanta
E
4
C
B2
A
1
5 D 3
Packet-Switched Networks Data, Voice, Video
All converted to packets Packet has data, destination, and source address Switched services Packets routed as needed Reassembled at destination
Introduction to MIS 10
Network Components Computers Servers Work stations
Media Cables Fiber optic Radio Infrared
Connection devices
LAN cardLAN card
LAN card
LAN card
Shared PrinterServer
Personal ComputerPersonal Computer
Router or Switch
Internet
Firewall
Introduction to MIS 11
Server Scalability
Sun 10000
Sun 3800
Sun Ultra 5
Compaq
Increasing performance within a product family.
Server farms distribute the workload. Add more computers for more power.
Rack mount server farm.
Introduction to MIS 12
Network Transmission Media Electricity Fiber optics Radio waves
CoaxialExample:Cable TV
Shield
Radio or Micro WavesExample:Cellular phones
glass or plastic
Fiber Optic CableExample:Long distance phone lines
antenna
Twisted PairExample:Local phone lines
reflective cladding
Introduction to MIS 13
Fiber Optics Faster More data Less magnetic interference Long stretches without
repeaters
900 copper wires can be replaced by one fiber optic line (for telephone connections).
Introduction to MIS 14
Frequency Spectrum
All waves behave similarly Sound Radio Micro Light
Frequency differences Amount of data Distance Interference / Noise
ELF VLF LF MF HF VHF UHF Microwave Optical
100 1K 100K 1M 10M 100M 1G 10G Hertz
Navy/s
ubm
arine
s
TV: 22
0M -
500
MHz
AM:
550K
- 16
50 K
Hz
Public
Saf
ety:
150
M -
160
MHz
Public
Saf
ety:
460
M -
500
MHz
Cellula
r pho
nes:
800
MHz
Cordle
ss p
hone
s (s
ome)
: 90
0 M
Hz
Pers.
Com
. Sys
(PCS):
1.8
5 G -
2.2
GHz
PCS E
T: 2
GHz
TV: 54
M -
216
MHz
FM:
88M
- 10
8 M
Hz
http://www.jsc.mil/images/speccht.jpg
http://www.ntia.doc.gov/osmhome/allochrt.pdf
Introduction to MIS 15
Transmission Capacity
A thin fiber optic cable can carry as much data as 900 single copper wires, with minimal interference, and superior tensile strength.
Introduction to MIS 16
The Importance of Bandwidth
Introduction to MIS 17
Shared Connections
With shared connections, machines have to take turns, and congestion can slow down all connections.
With switched connections, each computer has the full bandwidth of the connection at all times. Performance depends on how fast the switch can handle connections.
Introduction to MIS 18
Time Division
A B
DC
timeA C A C A
Computers A and C split their messages into packets and sharethe transmission medium by taking turns sending the data.
Introduction to MIS 19
Frequency Division
A B
DC
fre
que
ncy
3500 Hz
A
C
Computers A and C split the frequency: A uses a higher spectrum.By listening only to the assigned frequency, multiple transmissionscan occur at the same time.
Introduction to MIS 20
Spread Spectrum
A B
DC
fre
que
ncy
time
Sharing a medium by both frequency and time is one methodof spread spectrum transmission. It is efficient for many computersbecause the full bandwidth can be utilized over time and frequency.
Introduction to MIS 21
Wireless Communication
Microwave transmissions are used to provide communications for cellular phones and laptop computers. As prices of phones, portable computers, and communication costs decrease, increasing numbers of workers are choosing wireless technologies.
Introduction to MIS 22
Connecting Networks The need for standards A changing environment
Backbone fiber optic
Hub
Switch
Hub
Radio-based network
Internet
Routers or Switches
Introduction to MIS 23
Shared-Media Network
Shared MediaTap
Introduction to MIS 24
Switched Network
Switch
Servers
Workstations/PCs
Introduction to MIS 25
Building 1Building 2
Enterprise Network
Switch
Servers
Workstations/PCs
Fiber optic
Internet – ISP
Firewall
Subsidiary
Introduction to MIS 27
TCP/IP Reference Model
Message
Header 3 Trailer 3Message
Header 3 Trailer 3MessageHeader 3 Trailer 3MessageHeader 2 Trailer 2
Header 3 Trailer 3MessageHeader 3 Trailer 3MessageHeader 2 Trailer 2Header 1 Trailer 1
4. Application
3. Transport (TCP)
2. Internet (IP)
1. Physical
Introduction to MIS 28
TCP/IP Reference Application
Mail, Web, FTP Authentication, compression, user services
Transport Packetize data and handle lost packets Establish connections through numbered ports
Internet Protocol (IP) Route packets to destination Requires unique host addresses: IPv4=32-bit; IPv6=128-bit Requires standards and cooperation
Subnet Physical connections Transfers bits with some form of error correction
Introduction to MIS 30
The Internet
Introduction to the Internet No control Services
Mail Telnet FTP WWW
WEB searching AltaVista HotBot Lycos WebCrawler Yahoo
Introduction to MIS 31
How the Internet Works
Individual
Internetserviceprovider (ISP)
Phonecompany
Networkserviceprovider (NSP)
Backbonenetwork
Phonecompany
CompanyWeb site
Dial-up: 33.3 - 56 KbpsISDN: 128 KbpsDSL: 256 Kbps - 6 MbpsCable: 1 to 10 Mbps
Cablecompany
T1: 1.544 MbpsT3: 44.736 Mbps
OC3: 155.52 MbpsOC12: 622 Mbps
Introduction to MIS 32
M-Commerce
Internet access everywhere
Cell phones
PDAs
Laptops
Great potential
Limited usability
Better than voice?
Introduction to MIS 33
Cell Phones and Wireless Communication
Wireless cells work by handing off the wireless connection to the next tower as the caller moves.
Connections to multiple towers at one time enables the system to triangulate to get a fairly precise location of the cellular device--even when it is not in a call.
Location knowledge will make it possible (although perhaps not desirable) to offer new business opportunities as people move into range.
Introduction to MIS 34
Global Telecommunications Technical problems
Multiple standards Language Developing nations Time zones Limits to space & waves
Political complications Transborder data flows Taxes Privacy Accessibility
Cultural issues What is an object? Management & control
Introduction to MIS 35
Cases: Ben & Jerry’sKrispy Kreme
Starbucks Coffee
Introduction to MIS 36
Appendix: Creating Web Pages Determine the content. Define a style. Create each page.
Text Graphics
Link the pages. Test your work. Transfer pages to a Web site.
Introduction to MIS 37
Appendix: Style Sheets BODY { margin-left: 5px;font: 10pt "Times New Roman", Times, serif;color: black;text-align: left;background-color: #e0ffff;}
P { margin-left: 0px;font: 10pt "Times New Roman", Times, serif;color: black;background: transparent;}
H1 { margin-left: 0px;
font: 16pt "Times New Roman", Times, serif;color: black;font-weight: bold;background: transparent;}
Page 3
Page 2
Page1
Style Sheet
Body { … }
P {…}
Introduction to MIS 38
Appendix: Sample HTML<HTML>
<HEAD>
<TITLE>Sample HTML Page</TITLE>
</HEAD>
<BODY>
<H1>Section One</H1>
<P>This is a sample paragraph on a sample page.</P>
</BODY>
</HTML>
Introduction to MIS 39
Appendix: Publishing Files
Your computer
Web server
Internet or intranet
Initialpages
AccessibleWebpages
Transfer methods:
Microsoft Front Page extensions
FTP: file transfer protocol
Introduction to MIS 40
Web Development Hints Start with a tool like Microsoft Word (or Front Page, etc.). Get a good graphics package Keep page size small
30,000 - 50,000 bytes typically takes 8 - 15 seconds First develop the pages on your own computer.
Test all links. Transfer later.
Use style sheets. Consistency. Ease of change.
Study design elements and art. Formal training/art classes. Study other sites. Watch for and create trends.