MGMT 2006 – Management
Information Systems I
Module 6
Telecommunications and Networks
Simon Fraser
simon.fraser@sta.uwi.edu
Objectives
By the end of this module you should be able to:
– describe the basic components of a
telecommunications system.
– evaluate transmission media.
– discuss the advantages and disadvantages of
various network topologies.
– discuss how telecommunication networks are
used in contemporary organizations.
– recommend general networking strategies.
What is Telecommunications?
• Communication of information by
electronic means
• Includes digital data transmission as
well as voice and video transmission
Telecommunications Trends
• Rapid technological innovation
• Deregulation and liberalization
• Telephone, data and television networks begin
to converge
• Convergence of computer and
communications technology
• Growing dominance of the Internet as the
“uber network”
• Wireless, wireless and yup … wireless!
Telecommunications Value
• Declining transaction costs
• Declining agency costs
• Increased agility as firms are better able to
sense and respond to changes in their
environment.
• Higher quality management decisions
• Declining geographical barriers
• Declining temporal barriers
Telecommunications Value
Metcalf’s Law
Components of a Telecomm System
• Computers to process information
• Terminals or any input/output devices that
send or receive data
• Communications processors. In the old days
these were called multiplexers. These days
these are called switches and routers.
• Communications software
Wireless
Hub
Checkpoint
Firewall
running
secure OS
Cisco
Router
Network running
Dell Servers IOS
Switch
running
Windows
2000 Server IBM AS400
or Linux Minicomputer
running OS 400
Personal Computers
running Windows XP
Pro, Mac OS X or Linux
Dumb Terminals with no
Operating System
Laptops running
Windows XP Pro
Functions of a Telecomm System
• Establish interface between sender and the
receiver
• Transmit information
• Route messages along most efficient paths
• Perform error correction
Functions of a Telecomm System
• Perform elementary processing of information
• Convert message speed or format
• Control flow of information
Types of Telecoms Signals
Analog signal
• Continuous waveform
• Passes through communications medium
• Used for voice communications
Types of Telecoms Signals
Digital signal
• Discrete waveform
• Transmits data coded into two
discrete states as 1-bits and 0-bits
• Used for data communications
Modem
• Translates computer’s digital
signals into analog and vice versa
The Modem
Telecommunications Media
• Twisted wire: Telephone systems
• Coaxial cable: Cable television
• Fiber optics: Voice, Video, Data
• Wireless transmission: Microwave,
Satellites, Paging systems, Cellular telephones,
Personal communication Services, Personal
digital assistants, Mobile data networks
Fiber Optic
Twisted Pair
Coaxial
Speed, Distance and Cost
• Speed: How many bits per second (bps) can the
media transmit.
• Distance: How far can the media send the signal
without significant signal loss.
• Cost: How much does each media type cost per
foot, kilometer, etc.
• Flexibility: How easy is it to work with, to bend, etc.
• Security: All things being equal it is easier to
intercept wireless signals.
Telecommunications Media
• Twisted wire: Cheap, very flexible, moderately
fast, fair distance
• Coaxial cable: Cheap, flexible, fast, fair distance.
• Fiber optics: Expensive, not very flexible, very
fast, huge distances.
• Wireless transmission: cheap to expensive,
relatively slow, very flexible, short range to
intergalactic distances
Network Topologies
• Star Network: All computers and other devices
are connected to a central node/host.
• Bus Network: Links a number of computers by a
single circuit
• Ring Network: All computers are linked by a
closed loop
• Mesh: Each node is linked to two or more
computers.
Star Network
Bus Network
Ring Network
Mesh Network
Hybrid Network
Systems Check
• Name five telecommunication trends
Systems Check
• What is Metcalf’s Law? What does it lead you
to predict about telecommunications
investments in the future?
Systems Check
• What type of media would you buy if you had
to wire up 50 personal computers and a server
in a new computer lab?
Systems Check
• What type of media would you buy if you had
to connect twenty buildings on your campus
to the computer center.
Types of Networks
Personal Area Networks (PANS)
– Bluetooth standard: Up to 720 Kbps,
small personal area networks
Network Types
Local Area Networks
• Require their own dedicated channels
• Encompass a limited distance
• Gateway, router, Network Operating
System (NOS), peer-to-peer
Local Area Network (LAN)
Types of Networks
Campus Area and Metropolitan Area
Networks (CANS and MANS)
– Span intermediate geographical
distance
– Consist of variety of cable, and
microwave technologies
– Switched lines, dedicated lines
Types of Networks
Wide Area Networks (WANs)
– Span large geographical distance
– Consist of variety of cable, satellite,
and microwave technologies
– Switched lines, dedicated lines
Network Uses
Electronic Mail and Groupware
• E-mail: Eliminates telephone tag and
costly long-distance telephone charges
• Groupware: Enables work groups at
different locations to participate in
discussion forums and work on shared
documents and projects
Network Uses
Voice Mail and Fax
• Voice mail: Digitizes spoken message and transmits it
over a network
• Fax: Digitizes and transmits documents over telephone
lines
Network Uses
• Teleconferencing: Ability to confer
with a group of people
simultaneously
• Data conferencing: Two or more
users can edit and modify data files
simultaneously
• Videoconferencing: Participants are
able to see each other over video
screens
Network Uses
• Distance learning: Education or
training delivered over a distance to
individuals in one or more locations
• Electronic Data Interchange: EDI
refers to the direct computer-to-
computer exchange between two
organizations of standard business
transaction documents
The Biggest Network of Them All
The Internet
The ARPANET in 1969
First Four Nodes
The Origins of the Internet
• The Internet started as a networking project funded by the US Department of
Defense's (DoD) Advanced Research Project Agency (ARPA)
• A primary design goal was to allow users to share resources on remote computers.
Remember computers were very expensive and they were not too many of them
back in the 1960s.
• Legend has it that a secondary design goal was to build a reliable network capable
of operating in a hostile environment (war)
• The Internet went live with two nodes in 1969. Back then it was called the
ARPANET.
The Origins of the Internet
• The design goals led to a change in the way networks were
structured.
• Prior to the internet many networks were built around a few
centralized nodes. Remember the STAR topology?
• In attempting to satisfy their design brief the designers moved
away from centralized nodes to a distributed network.
The Origins of the Internet
• Centralized • Distributed
Node B
Nod
Node A Node A
eB
Node C Node
C
Host
Node F
Node G Node E
Node E
Node H
Node D
Node D
Node I
TCP and IP (the dynamic duo)
• In addition to moving away from centralized
networks the DoD also needed to connect
many different types of computers.
• To do this the researchers came up with
several protocols.
• The two best known are TCP and IP.
TCP and IP (the dynamic duo)
• TCP stands for Transmission Control Protocol.
• IP stands for Internet Protocol.
• If it is helpful you can think of these protocols
and languages that computers have
standardized on to allow for communication.
TCP and IP (the dynamic duo)
• TCP is responsible for the disassembly and reassembly of files
into packets and packets back into files.
• A large file could be converted into hundreds or thousands of
packets before being sent out over the network.
• Each packet is numbered so that the receiving machine can
reassemble them in the right order.
• Packet numbering also allows the receiving machine to detect
when a packet has been lost in transmission.
TCP and IP (the dynamic duo)
• File • Packets
My Term Paper
This is my term paper. It is My Term Paper
not very good but I hope sir
1
will give me an ease.
This is my term paper. It is not very
There were just too many good but I hope sir will give me an
ease.
fetes this semester and Zen 2
has a great new DJ.
There were just too many fetes this
Well I hope I pass. I need to semester and Nuts has a great new
get a lower second to go DJ
work for my uncle. I not 3
really into the First Class
ting. Dat is too much work. Well I hope I pass. I need to get a
lower second to go work for my
uncle. I not really into the First Class
ting. Dat is too much work. 4
Network Concepts
Packet Switching
TCP and IP (the dynamic duo)
• The Internet Protocol handles the
identification of nodes on the internet
(Clients, Servers, Routers) and the addressing
of packets.
• Each node has an IP address that looks
something like this 192.168.001.200.
• No two nodes have the same address.
TCP and IP (the dynamic duo)
• When TCP hands a packet off to IP, IP stamps each packet with
the source and destination address.
• Thus as the packets traverse the internet the packet
forwarding computers (routers) know where it is going and
where it is coming from.
• If a packet goes missing the destination machine sends a
message back to the transmitting machine requesting a
retransmission.
TCP and IP (the dynamic duo)
• Web Site • IP Address
– www.uwi.tt – 64.28.139.231
– www.hotmail.com – 65.54.211.93
– www.amazon.com – 207.171.166.102
– www.tstt.net.tt – 196.3.132.8
Systems Check
• Who sponsored the development of what we
now call the Internet?
A. IBM
B. MIT
C. DOD ARPA
D. Apple
E. Pentagon
Systems Check
• What was the primary design goal of the
Internet?
A. Create a telephone network for the government?
B. Build a robust network heterogeneous
computers.
C. Develop the TCP and IP protocols.
D. Share computer resources
E. None of the above.
Systems Check
• TCP is responsible for the addressing of
packets.
A. True
B. False
Systems Check
• Name two other addressing schemes with
which you are familiar.
The Domain Name System (DNS)
• One of the problems with the IP addressing
scheme is that humans have a hard time
remembering numbers.
• Can you remember any of the IP numbers
from the earlier slide?
• The Domain Name System addresses this
problem.
The Domain Name System (DNS)
• The Domain Name System is a huge database that allows
administrators to assign an easy to remember name to an IP
address.
• Thus www.amazon.com is mapped onto 207.171.166.102
• They both point to an Amazon web server. You can type in the
domain name or the IP address in your web browser and they
will bring up the same page.
• If the DNS is down it may still be possible to reach your server
by typing in the IP address.
The Domain Name System (DNS)
• The DNS is of particular interest to marketing
execs as it allows them to assign their brand to
an IP address.
• Thus you no longer have to remember
207.171.166.102.
The Domain Name System (DNS)
• Original Top Level Domains • Global Top Levels Domains
– .com – .tt
– .edu – .lu
– .gov – .bb
– .mil – .uk
– .org – .us
– .net – .fr
– .biz
– .info
– .pro
– .xxx
The Domain Name System
Total Sites Across All Domains to January 2007
Applications that use the Internet
• Applications • Protocols
– Electronic Mail – POP and SMTP
– The WWW – HTTP and HTML
– File Transfer – FTP
– Mailing Lists
– Newsgroups
– Archie
– Veronica
– Gopher
The World Wide Web
• Along with email, the WWW is now the most
popular application on the Internet.
• The WWW is a collection of software and
protocols that allow for the creation of a
hypertext environment.
• Hypertext allows documents to be linked via a
system of hyperlinks.
The World Wide Web
• The WWW is a client-server system that uses special
protocols to link machines.
• The web browser is the most popular form of client.
• Browsers request and display files provided by web
servers – computers configured with high end
operating systems and web server software.
The World Wide Web
• Browsers • Servers
– Internet Explorer – Apache/Linux
– Netscape – IIS/Windows 200X
– Firefox Server
– Mozilla – Netscape/Solaris
– Opera
The World Wide Web
• The world wide web relies on HTTP and HTML.
– HTTP = Hypertext Transfer Protocol
– HTML = Hypertext Markup Language
The World Wide Web
• HTTP sets up communications between the web browser and the web server.
• When you type in a domain name the web browser uses the DNS system to find
the IP address of the web server. The browser then issues a get command.
• The server receives the get command and determines what resources ( web pages)
have been requested. One the requested resources are available the server sends
them back to the browser. It knows here to send them because it has the browsers
IP address.
• The browser gets the pages and writes them to your screen.
The World Wide Web
• HTML is the markup language used to format
web pages.
• HTTP consists of hundreds of TAGs that
control the appearance of text and images.
– <b>help</b>
– <u> me </u>
– <li>
– <body></body>
The World Wide Web
(Some HTML from CaribbeanICT)
• table width="755" border="0" align="center" cellpadding="0" cellspacing="0" bordercolor="#666666"> <tr> <td
width="25%" align="left" valign="top"><table width="100%" height="175" border="1" cellpadding="2" cellspacing="0"
bordercolor="#CCCCCC"> <tr> <td height="20" align="left" valign="top" bgcolor="#336699"><div align="left" class="style17"
style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12px; color: #FFFF00; font-weight:
bold">Welcome</div></td> </tr> <tr> <td height="155" align="left" valign="top"><span style="font-family: Verdana, Arial,
Helvetica, sans-serif; font-size: 12px">Welcome to Caribbean ICT. This site hosts material for my students at the Department
of Management Studies and Institute of Business at The University of the West Indies in Trinidad.</span></td> </tr>
</table></td> <td width="2%"> </td> <td width="40%" align="left" valign="top"><table width="100%" height="175"
border="1" cellpadding="2" cellspacing="0" bordercolor="#CCCCCC"> <tr> <td height="20" align="left" valign="top"
bgcolor="#336699"><div align="left" class="style17" style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12px;
font-weight: bold; color: #FFFF00">Courses</div></td> </tr> <tr> <td height="155" align="left" valign="top"><span
style="font-size: 12px; font-family: Verdana, Arial, Helvetica, sans-serif">If you need material for Management Information
Systems I, Introduction to Electronic Commerce, Electronic Commerce Site Design and Implementation, Introduction to
Information Security or eCommerce Marketing you have come to the right place. (<a
href="courses/courses.htm">More</a>) </span></td> </tr> </table></td> <td width="2%"> </td> <td width="25%"
align="left" valign="top"><table width="100%" height="175" border="1" cellpadding="2" cellspacing="0"
bordercolor="#CCCCCC"> <tr> <td height="20" align="left" valign="top" bgcolor="#336699"><div align="left" style="font-
family: Verdana, Arial, Helvetica, sans-serif; font-size: 12px; font-weight: bold; color: #FFFF00">What's New</div></td> </tr>
<tr> <td height="155" align="left" valign="top"><span style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size:
12px">This site is under construction so please revisit often in the next few weeks as I release additional material.
</span></td> </tr> </table></td> </tr> </table>
The World Wide Web
• Hypertext - the magic of the web
– <a href=“http://www.courses.com/courses.htm">
The World Wide Web
• Move over HTML here comes the new kid in
town XML.
• Whereas HTML focuses on the layout of a web
page XML focuses on the content of the page.
• HTML tags define how things look. XML tags
define what the are.
The World Wide Web
• XML can be used to develop industry specific
markup languages.
• Thus you can have specific tags for
– Insurance
– Banking
– Travel
– Manufacturing
– Education
– Etc.
Who Manages the Internet?
• No one “manages” the Internet.
• The Internet works because everyone has
agreed to adopt the protocols needed to make
it work.
• However several agencies are tasked with
overseeing the specifications for these
protocols.
Who Manages the Internet?
• Standards Bodies • Standards
– W3C – HTML, XML, XHTML
– ICANN – DNS System
– IETF – TCP/IP
– ARIN, RIPE, APNIC – IP Addresses
Who Manages the Internet in Trinidad.
• If you want a top level .tt domain
(www.uwi.tt) you can go to www.nic.tt
Systems Check
• What is Moore’s Law?
• What is Metcalf's Law
Systems Check
• Which protocol governs the communication
between a web browser and server.
A. HTML
B. TCP
C. IP
D. HTTP
E. POP
Systems Check
• XML controls the appearance of text on a
page?
A. True
B. False
Systems Check
• What does the Domain Name System do?
Further Reading
• You can read more about the Internet at
– www.howstuffworks.com
– www.wikipedia.com
– www.webopedia.com
Objectives
By the end of this module you should be able to:
– describe the basic components of a
telecommunications system.
– evaluate transmission media.
– discuss the advantages and disadvantages of
various network topologies.
– discuss how telecommunication networks are
used in contemporary organizations.
– recommend general networking strategies.
