Introduction to MIS1 Copyright © 1998-2002 by Jerry Post Introduction to MIS Chapter 3 Networks and Telecommunications.

Introduction to MIS 1

Copyright © 1998-2002 by Jerry Post

Introduction to MIS

Chapter 3

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 B 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 B 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

WirelessCommunication

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

Internet Connections Backbone providers AT&T GTE Worldcom/MCI Sprint Qwest

Network service providers 1998: 39 AGIS AT&T Cable & Wireless IBM MCI/Worldcom Qwest Sprint UUNet

Phone companies Regional Bell operating

companies (RBOCs) (6) Competitive local exchange

carriers (CLECs) (new) Cable companies

AT&T Cablevision Regional.

Satellite Direct Satellite Starband

Internet service providers America Online Microsoft Network Earthlink

Introduction to MIS 33

M-Commerce

Internet access everywhere

Cell phones

PDAs

Laptops

Great potential

Limited usability

Better than voice?

Introduction to MIS 34

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 35

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 36

Cases: Specialty Retail

Introduction to MIS 37

Cases: Ben & Jerry’s

Introduction to MIS 38

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 39

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 40

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 41

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 42

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.