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Networks and Telecommunications

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					Introduction to MIS

    Networks and
 Telecommunications

      Prof. Rushen Chahal




                            Page 1
                       Outline
• What is the value of a single computer?
• Why are computer networks so important in today’s
  businesses?
• What components do you need to install to create a
  network?
• Why does it matter how your computer is connected to
  the network?
• How is it possible that you can connect your computer to
  a network at the office, at home, or while on the road,
  even overseas?
• What is the Internet, how is it controlled, and how does it
  work?
• What problems are you likely to encounter if you need to
  connect to a supplier in a different country?          Page 2
Internal
Teamwork        Networks
Communication
Scheduling           Internet
Sharing




                                   Services
                                   Applications
                                   Research
                                   Hosting
                       External
                       Suppliers
                       Customers
                       Banks


                                         Page 3
Sharing Data: Transactions


                          Internet




Database Management
System and Web Server
Or Point-of-Sale system




                                     Page 4
Sharing Data: Decisions &
Decisions & collaboration
            Collaboration and Database
Teamwork & joint authorship
                            File Server




         Team Document




              Report and
              Comments




                                          Page 5
       Sharing Data: E-mail

                 Internet


2. Message                    3. Transferred
transferred to                via the Internet
account on                    to the
server.                       destination
                              account.


                                                 4. Message
                                                 received when
                                                 user checks e-
  1. User creates e-mail message.                mail.



                                                           Page 6
Sharing Data: Calendars


        8:00    Mgt meeting
        8:30    (open)
        9:00    Staff meeting
        9:30    Staff meeting
        10:00   new meeting




                                Page 7
         Hardware Sharing
            Printers
                    Storage
Corporate or        Processors
external computer
access                         tape drive
                               (backup)
                                                            Workstations




                                   Server
         Shared Printer

        Files are transferred from workstations to the server.
        Software automatically copies files to tapes.
        LAN administrator can restore files if needed.



                                                                  Page 8
                  Network Components
           • Computers
              – Servers
              – Work stations
           • Media                   Personal Computer
              –   Cables                                  Personal Computer
                                           LAN card
              –   Fiber optic                                       LAN card
              –   Radio
              –   Infrared
           • Connection devices

Internet

                     Router
                                                                     LAN card

                                                         LAN card

                                Switch                                 Shared Printer
       Firewall                                  Server


                                                                               Page 9
       Server Scalability
                           Server farms distribute
                           the workload. Add
                           more computers for
                           more power.

Sun 10000     Increasing
              performance
              within a
              product family.


Sun 3800                         Rack mount
                                 server farm.

                                                     Compaq

Sun Ultra 5

                                                     Page 10
Network Transmission Media
                         Fiber Optic Cable
                         Example:
                         Long distance phone lines
                       reflective cladding

 Twisted Pair
 Example:
 Local phone lines     glass or plastic


                     Radio or Micro Waves
                     Example:
                     Cellular phones

                                             antenna


Coaxial
Example:
Cable TV




                                                  Page 11
                      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).




                                                       Page 12
http://www.jsc.mil/images/speccht.jpg
                    Frequency Spectrum


ELF           VLF        LF       MF    HF         VHF      UHF    Microwave Optical

        100         1K        100K     1M    10M         100M     1G       10G         Hertz

•     All waves behave similarly
       –   Sound
       –   Radio
       –   Micro
       –   Light
•     Frequency differences
       –   Amount of data
       –   Distance
       –   Interference / Noise


      http://www.ntia.doc.gov/osmhome/allochrt.pdf
                                                                                 Page 13
Wireless Technologies
         Cellphone or WiMax
         2-10 miles, 128 kbps - 3 mbps




               Bluetooth
               10-30 feet
               1 mbps

     Ultra-wideband            Wi-Fi
     10-30 feet                50-200 feet
     1 gbps                    11 mbps - 500 mbps


                                           Page 14
Local Area Networks
Name                   Format         Speed (mbps)
10Base-T               Twisted pair   10
100Base-T   Transmission Capacity
Gigabit Ethernet
                       Twisted pair
                       Twisted pair
                                      100
                                      1000
Wireless LAN 11b,a,g   Wireless       11-54
Wireless LAN 11n       Wireless       100
LAN/fiber FDDI         Fiber optic    100
LAN/fiber ATM          Fiber optic    155
LAN/fiber high-end     Fiber optic    10,000
Internet Connections
Name                   Format         Speed (mbps)       Estimated Cost
Dial-up                Twisted pair   0.05               $24/month
DSL                    Twisted pair   1.5 down/0.13 up   $50/month
Cable modem            Coaxial        2.5 down/0.58 up   $50/month
Satellite              Microwave      1.5 down/0.25 up   $50/month
Wireless/Wi-Max        Microwave      1.5 down/0.25 up   $40/month
T1-lease               Twisted pair   1.544              $400-$700/month
T3-lease               Fiber optic    45                 $2,500-$10,000/month
ATM                    Fiber optic    155                $15,000-30,000/month
OC-3                   Fiber optic    155                $16,000-$20,000/month
OC-12                  Fiber optic    622                $20,000- $70,000/month
OC-48                  Fiber optic    2,488
OC-192                 Fiber optic    9,953
OC-768/future          Fiber optic    39,813




                                                                                  Page 15
The Importance of Bandwidth

                     Text        Image          Video-10 sec
   Bytes             10,000          500,000      15,000,000
   Bits              80,000        4,000,000    120,000,000
                                     seconds
   Dial-up 50 kbps     1.6            80           2400
   DSL 1.5 mbps        0.05             2.67         80
   LAN 10 mbps         0.008            0.4          12
   LAN 100 mbps        0.0008           0.04          1.2
   Gigabit 1 gbps      0.00008          0.004         0.12




                                                               Page 16
• The need for standards
         Connecting Networks
• A changing environment



                                                          Internet
              Backbone fiber optic

                      Routers or Switches

                                                 Switch


        Hub

                                     Hub

                           Radio-based network

                                                          Page 17
          Enterprise Network
   Building 1
                                          Building 2
                 Fiber optic
                                          Switch



                                                       Servers
                               Firewall



                                             Workstations/PCs



Internet – ISP
                                Subsidiary

                                                         Page 18
Packet-Switched Networks
•All data is converted to packets.
•Packet has data, destination, and source address.
•Switched services.
                                         Voice        Sent as packets: 1 2 3 4 5
•Packets routed as needed.
                                                  B
•Reassembled at destination.         Chicago
                                                            2
                                                                    New York
                                     C

                                 4                                        A


                             E                                        1
                                                                Atlanta
                            Dallas          D          3
                                     5

                                 Computer        Sent as packets: A B C D E


                                                                      Page 19
      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.



                                                                Page 20
Switched Network
Switch




                   Servers




     Workstations/PCs


                             Page 21
Shared-Media Network




   Tap    Shared Media




                         Page 22
              Time Division
     A                   B




                                         A    C   A   C   A time
     C                    D

Computers A and B split their messages into packets and share
the transmission medium by taking turns sending the data.




                                                          Page 23
        Frequency Division




                                       frequency
    A                   B

                                                                A
                                  3500 Hz

                                                                C
   C                     D


Computers A and B split the frequency: A uses a higher spectrum.
By listening only to the assigned frequency, multiple transmissions
can occur at the same time.


                                                           Page 24
        Spread Spectrum




                               frequency
  A               B




  C                D
                                                            time

Sharing a medium by both frequency and time is one method
of spread spectrum transmission. It is efficient for many computers
because the full bandwidth can be utilized over time and frequency.




                                                           Page 25
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.



                                      Page 26
           TCP/IP Reference Model


4. Application                                    Message


3. Transport (TCP)                     Header 3   Message   Trailer 3


2. Internet (IP)            Header 2   Header 3   Message   Trailer 3   Trailer 2


1. Physical      Header 1   Header 2   Header 3   Message   Trailer 3   Trailer 2   Trailer 1




                                                                                    Page 27
          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; 28
                                            Page
       Introduction to the Internet
• No control
• Services
   –   Mail
   –   Telnet
                            The Internet
   –   FTP
   –   WWW
• WEB searching
   –   AltaVista
   –   HotBot
   –   Lycos
   –   WebCrawler
   –   Yahoo



                                           Page 30
             How the Internet Works
               Network
                                                           OC3: 155.52 Mbps
                     service
                                                           OC12: 622 Mbps
                     provider (NSP)


T1: 1.544 Mbps
                                      Backbone
T3: 44.736 Mbps
                                      network

   Internet
   service
   provider (ISP)

                            Phone     Cable          Phone
                            company   company        company

                                 Dial-up: 33.3 - 56 Kbps
                                 ISDN: 128 Kbps
                                 DSL: 256 Kbps - 6 Mbps            Company
        Individual               Cable: 1.5 Mbps                   Web site


                                                                    Page 31
       Internet Connections
• Backbone providers
   –   AT&T
   –   Level 3
   –   MCI (UUNet)            • Phone companies
   –   Sprint                     – Regional Bell operating
   –   Qwest                        companies (RBOCs) (3)
• Network service providers       – Competitive local exchange
                                    carriers (CLECs) (new)
   –   1998: 39
   –   AGIS                   • Cable companies
   –   AT&T                       – Cablevision
   –   Cable & Wireless           – Comcast
   –   IBM                        – Regional.
   –   MCI/Worldcom           • Satellite
   –   Qwest                      – Direct Satellite
   –   Sprint                     – Wild Blue/Starband
   –   UUNet                  • Internet service providers
                                  – America Online
                                  – Comcast
                                  – SBC
                                                             Page 32
     Colocation and Hosting
General Data Centers Equinix
                  Companies
Multiple high-speed  Cybercon
Internet connections,        Savis
power with UPS, air          Telecity (Europe)
conditioning, and security
Specialty Hosting            IBM
Companies                    AT&T
Individual contracts to      EDS
perform specific tasks       Thousands of small, regional
including hosting.             providers




                                                        Page 33
Distributed Content through
            Akamai
          Akamai Servers


Company Server

                                 Internet


           Content
           Video

By distributing your content to servers
at the “edge” of the Internet,
customers retrieve data from multiple
points, reducing the load on your
server and Internet connection.

                           http://www.akamai.com
                                                   Page 34
   Voice Over IP (VoIP)
                    VoIP Provider

                                    Telephone Co.




               Internet



              Cable
              modem




Voice to IP


                                                    Page 35
Network Address Translation
          (NAT)

                                           Web Server


                         Translate:
     10.1.30.15          10.1.30.15=138.9.1.15




          Disallow
          incoming
          peer-to-peer


                                                  Page 36
                 Domain Name System
                                  Internic.org
                    Registration       DNS
                                                    Registration
             Internet World   ISP
                                                 207.46.250.222
                                                 www.microsoft.com
Arin.net                                         Microsoft Corporation
                                                 One Microsoft Way
 Net Range                                       Redmond, WA 98052
                                                 US
207.46.0.0 –                        Real World
207.46.255.255
                                                      Internet entities
Microsoft-                                            are anchored to
Global-Net                                            the real world
                                                      through the DNS
                                                      registration and
                                                      through their ISP.
                                                      If they tell the
                                                      truth!


                                                              Page 37
             Domain Names
                     Right-to-left
                                           Original TLDs
                                           Set by ICANN
      Server.Department.Company.TLD
                                           com
        Optional               Required    org
                                           net
                                           edu
                                           gov
                                           mil
accounts.citibank.com.xqioajfm.aka82.com
                                           Many more today
This address is NOT owned by Citicorp.     +
When you see it in an e-mail message,      Country Codes
you know it is a fake.




                                                       Page 38
M-Commerce
         Internet access
         everywhere
         Cell phones
         PDAs
         Laptops


         Great potential
         Limited usability
         Better than voice?

                           Page 39
Cell Phones and Wireless
     Communication off thework by
                Wireless cells
                handing        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.



                                                Page 40
     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

                                  Page 41
   Technology Toolbox: Creating
HTML
     <HTML>
                  Web Pages
     <HEAD><TITLE>Sample HTML Page</TITLE>
      <BODY>
      <H1>Section One</H1>
      <P>This is a sample paragraph on a sample
      page.</P>
      </BODY>
      </HTML>


      Tables for Layout
      Page Editors
      Images are bitmaps: GIF, JPEG, PNG
      Adobe PDF




                                                  Page 42
Quick Quiz: Creating Web
                Pages
Create a document to do the following in HTML:
1. Display a word or phrase in boldface.
2. Link a style sheet to an HTML page.
3. Display a table with three rows and four columns.
4. Display a numbered list of five items.
5. Display an icon in GIF format with a transparent
   background.




                                                  Page 43
          Technology Toolbox:
Connection Transferring Files
             Strengths     Weaknesses
FTP         Inexpensive and easy to   No security.
            use.
FrontPage   Very easy to use with     Limited availability and users have
            secure login.             to purchase client software.
WebDAV      Internet standard and     Web server security is weaker by
            can be secure.            allowing directory browsing.
VPN         Very secure.              Need to purchase server and client
                                      software and requires extra setup
                                      steps.




                                                                Page 44
Quick Quiz: Transferring Files
 1. Which methods can you use to transfer files to a
    university server?
 2. Why is FTP considered a security threat?
 3. What other objections exist to FrontPage?




                                                  Page 45
                                                Annual Revenue

            7

            6
                                                                                                        Cases:
            5

                                                                                       W.W. Grainger
                                                                                                        Wholes
Billion $



            4
                                                                                       Univar
            3

            2
                                                                                       Ow ens & Minor

                                                                                                          ale
            1

            0
                1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006                        Supplie
            0.07
                                             Net Income / Revenue
                                                                                                          rs
            0.06

            0.05

            0.04
                                                                                       W.W. Grainger
            0.03                                                                       Univar
                                                                                       Ow ens & Minor
            0.02

            0.01

                0
                    1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
            -0.01




                                                                                                            Page 46

				
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Description: Prof Rushen's notes for MBa and BBA students