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					    Computer Networking – Part 2

                                                MIS 320
                                               Kraig Pencil
                                               Winter 2011

PPT Slides by Dr. Craig Tyran & Kraig Pencil
                             A. Game Plan
•   Introduction (Part 1 notes)
•   Distributed processing (Part 1 notes)
•   Client/Server processing (Part 1 notes)
•   Local area networks (Part 1 notes)
•   Wide area networks
•   Wireless networks
•   Cloud Computing
PPT Slides by Dr. Craig Tyran & Kraig Pencil
                 H. Wide Area Networks

1. Wide area network (WAN)
   – May span 100s  1000s of miles  globe
   – May connect LANs
   – Organizations often lease communication lines
       (from AT&T, Verizon-MCI, Sprint, etc.) to
       establish a private network
   – Common for international organizations
   – If all of an organization is hooked up, call it an
       “Enterprise Network”
   – Example: See figure next slide
   PPT Slides by Dr. Craig Tyran & Kraig Pencil
                 LANs and Wide Area Network at
                 Metropolitan Life Insurance Co.




LANs
(Located at
                                                   WAN
regional
office)




   PPT Slides by Dr. Craig Tyran & Kraig Pencil
          H. Wide Area Networks (cont.)               Source: www.campusvillagetoledo.com/speed.htm
2. The Internet: A type of WAN:
   •      A network of networks
   •      Evolution
         • When was it created?
         • Why was it created?
         • Who were the early users??




       PPT Slides by Dr. Craig Tyran & Kraig Pencil
          H. Wide Area Networks (cont.)               Source: www.campusvillagetoledo.com/speed.htm
2. The Internet: (continued):
    • “Top innovation” of
        past 25 years
         •      CNN (1/18/05)*
         •      Note: the Internet was
                created in 1972, but its
                impact wasn’t widely felt
                until the 1995-2005 decade.


   •      Governance/Ownership ???
         • The Internet Society – education / standards            “If you buy a server, a router, a
                                                                   domain name, and a connection to
         • ICANN – issues domain names                             the Internet from your phone
                                                                   company, the data on your
         • Telecom/Cable/ISPs – cables, access, servers            computer can become a part of the
                                                                   Internet and you would own that
                                                                   part.” http://en.allexperts.com/q/Internet-
                                                                   Media-2495/2008/1/Internet-ownership.htm
       PPT Slides by Dr. Craig Tyran & Kraig Pencil
       H. Wide Area Networks (cont.)
                                                                           Image Source:
3. Virtual private network (VPN)                                           www.alpha-
                                                                           apr.com/vpn/
   •      A “virtual” software extension of a private network.
   •      It has no hardware of its own. It transmits over a public network (usually
          the Internet).
        •      VPN software protects the security of the internal network by requiring
               authorization. It protects transmitted data through encryption.
        •      Example : sales people in the field can log into the internal network
               from anywhere over the Internet.
   •      Advantages
         • Flexible: connect from anywhere
         • More secure than basic Internet
         • Less expensive than leased WAN


   PPT Slides by Dr. Craig Tyran & Kraig Pencil
                          VPN at WWU




PPT Slides by Dr. Craig Tyran & Kraig Pencil
       H. Wide Area Networks (cont.)
4. Does the Internet = World Wide Web (WWW)?
     – Internet  Describes the computer network infrastructure
     – WWW  An information sharing approach used by
       clients/servers on the Internet
        • Invented (1989-91) by Tim Berners-Lee (Oxford/CERN)
        • Composed of a “web” of documents
           with links to other documents
        • Hosted by client-servers connected to the Internet
        • Uses a “browser” application to
           display the document
Illustration: http://www.w3.org/2007/Talks/1211-whit-tbl/#(1)

    PPT Slides by Dr. Craig Tyran & Kraig Pencil
       H. Wide Area Networks (cont.)
4. Internet = WWW? (continued)
      • WWW uses “HTTP”: Hyper Text Transport Protocol
             – Defines how messages are formatted and transmitted
      • What happens when you submit a URL via web browser?
             – Determine protocol
             – Find the server
             – Request/display file



                                                   http://www.wwu.edu/mis320.html


    PPT Slides by Dr. Craig Tyran & Kraig Pencil
            WWW Popularized Internet Usage




http://en.wikipedia.org/wiki/File:WIntHosts1981-2009.jpg         The Today Show -- 1994
                                                           http://www.youtube.com/watch?v=9nTPX4JW_Ts&feature=player_embedded
    PPT Slides by Dr. Craig Tyran & Kraig Pencil
         Running out of Internet “bandwidth”?

       • 2008 – often predicted we will run out of
         capacity (“bandwidth”) by 2011.
       • Growth of International Internet Bandwidth
       • What do you think?




•   http://arstechnica.com/tech-policy/news/2010/10/now-thats-
    bandwidth-international-net-links-add-13tbps-in-2010.ars

•   http://www.macworld.com/article/61123/2007/11/internetcap
    acity.html


    PPT Slides by Dr. Craig Tyran & Kraig Pencil
      I. Wireless Networks
1. A new frontier ??

2. Types of wireless networks
  •       Wireless local area networks (WLANs)
  •       Personal area networks (PANs)
  •       Wireless metropolitan area networks (WMANs)




 PPT Slides by Dr. Craig Tyran & Kraig Pencil
           I. Wireless Networks (cont.)
3a. Wireless local area networks (WLANs)
   • Similar to a LAN, without the cables
   • A fast-growing network
      technology for businesses
      (and individuals)
     • e.g., Laptop usage
             • 2002: 20% of business laptops
             • 2007 (est.): 99% of laptops
       • e.g., Business networking
             • UPS, hospitals

   PPT Slides by Dr. Craig Tyran & Kraig Pencil
            I. Wireless Networks (cont.)
3b. WLAN: What is Wi-Fi?
   • Wi-Fi: “Wireless Fidelity”
   • Based on “IEEE 802.11” set
      of protocol standards
        •     Ethernet with CSMA/CD



  •      Short range transmitter-receiver (up to 300 ft)
         communicates with Wi-Fi NIC receiver
         card/antenna
         54 Mbps                                 Sources: NetGear, Linksys

  PPT Slides by Dr. Craig Tyran & Kraig Pencil
               I. Wireless Networks (cont.)
3c. WLAN: “Hot spots”
   •      Location that offers access to Wi-Fi network
         •      e.g., WWU Red Square, Starbucks, airports, hotels
   •      Want to find a hot spot?
         •      CNET Hotspot Zone
3d. WLAN: Concerns
   •      Limited range
   •      Security
         •      “War driving”
         •      Eavesdropping
         •      Wi-Fi typically needs to
                have security features
                enabled and configured
                (see http://www.cnn.com/SPECIALS/2004/wireless/flash.html )
       PPT Slides by Dr. Craig Tyran & Kraig Pencil     Image sources: Starbuck, WWU, www.gugli.it
            I. Wireless Networks (cont.)
4. Personal area networks (PANs)
  – Network for devices close to one’s person
      • e.g., phone, PDA, computer, wireless barcode
        scanner
  – Bluetooth technology (IEEE 802.15)
      • Can link multiple devices within 30 feet
      • 1 Mbps + transmission rate
  – Example applications
      • Earpiece for cell phone
      • Package scanning for UPS
      • Wireless mouse/keyboard

    PPT Slides by Dr. Craig Tyran & Kraig Pencil
         I. Wireless Networks (cont.)
5. Wireless metropolitan area networks (WMANs)
  – One approach: WiMax
         • Based on “IEEE 802.16” set
           of protocol standards
  – Advantages
         • Broad range (up to 31 miles)
         • High speed transmission              Historical progression:
           (75 Mbps)
                                                1G: analog cell phone
         • Wireless                             2G: digital cell phone
  – Implications …                              3G: digital cell phone + Internet
         • Will WiMax (or something             4G: high speed 3G
           like it) replace Internet
           cable-modem and DSL service?
 PPT Slides by Dr. Craig Tyran & Kraig Pencil
                                               Cloud Computing
                     Not cloud
                      Your data
                     and app is
                     on your
                     computer                     Also Cloud 
                                                  Your data or app
                                                  can be on any of
                                                  multiple servers
                                                  on the Internet
                Cloud 
                Your data or
                app is
                on a server on
                the Internet
PPT Slides by Dr. Craig Tyran & Kraig Pencil
                         Latest Hot Topic:
                         Cloud Computing
“Cloud” = “Internet”                             Some PR Videos for the Cloud
• Instead of running an application              • “SalesForce.com” offers CRM
  on your own computer, use a                      (customer relationship
  service from the web that does                   management) services “in the
  about the same thing.                            cloud”.
                                                     http://www.youtube.com/watch?v=a
                                                        e_DKNwK_ms
• Example                                        • The key idea in this video is that
    – Use Google Apps instead of                   cloud computing gives you the
      Microsoft Office applications.               flexibility to change quickly when
                                                   necessary.
                                                     http://www.youtube.com/watch?v=C
                                                        4O3ufQ23xg



  PPT Slides by Dr. Craig Tyran & Kraig Pencil

				
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