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The Internet The world’s largest network

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  1. The Internet The world’s largest network

  2. Connectivity and Communications • Definition -- ability to connect devices by communication lines to other devices • E-Mail • Video and Audio Conferencing • On-line Services • Internet and the WWW • (WWW is a service of the Internet) • Share Resources • Telecommuting

  3. Internet Facts • Estimated 450 million users • TUMAIL processes 50,000 email messages a day • It took 13 years for television to reach 50 million users - it took the internet less than 4 years!

  4. Internet • Worldwide group of connected networks that allow public access to information and services • No single organization owns or controls

  5. Starting Facts • Started as a network of four computers in SRI, UCLA , University of California at Santa Barbara, University of Utah (1969) • Advanced Research Projects Agency (ARPA) – ARPANET

  6. Pioneers of the Internet The Internet (and World Wide Web) was have today was created by some very bright, talented people who either had vision, or were inspired by other talented people’s visions. Though their ideas were not always popular, they pressed ahead. Their perseverance and hard work brought us to where we are today. There is a lot to be learned by studying these people, their early work and keeping in mind what they had to work with.Today, we owe a great deal for the wired world we enjoy, to the hard work of thesepeople.

  7. Internet Growth 1977: 111 hosts on Internet 1981: 213 hosts 1983: 562 hosts 1984: 1,000 hosts 1986: 5,000 hosts 1987: 10,000 hosts 1989: 100,000 hosts 1992: 1,000,000 hosts 2001: 150 – 175 million hosts 2002: over 200 million hosts By 2010, about 80% of the planet will be on the Internet

  8. Internet Growth • 1970s - Saw growth in the academic community • 1980s - NSF connected its network (Nsfnet to Arpanet forming the Internet). NSF served as the major backbone, TCP/IP, DNS • 1990s - Saw the introduction of commercial sites. NSFnet turned the backbone over to corporations, commercial firms and other companies, 1991-1992 – WWW, 1993 – Marc Andreesen introduces Mosaic for X • Today a network of networks all following the same rules for transmitting data

  9. Packet Switching • Data is sent out in sequence • Small chunks (packets) of data • Packets are passed from node to node "Packet switching is the breaking down of data into datagrams or packets that are labeled to indicate the origin and the destination of the information and the forwarding of these packets from one computer to another computer until the information arrives at its final destination computer. This was crucial to the realization of a computer network. If packets are lost at any given point, the message can be resent by the originator."

  10. Where do we go………… • Internet2 • Consortium of universities looking at new technologies

  11. Internet Terminology • Internet Addressing Scheme • DNS • SMTP • POP • ARPAnet • Backbone • ISP, OSP, WSP • Packets • TCP/IP • Server/Client

  12. Summary Facts • Network of networks • You need a computer,modem, and telephone line (or other network connection) and software: • School or work, On-Line Service, ISP • Developed in the 1960s are part DOD • Based on the research of Paul Baran • Packet Switched Network

  13. Domain Name System • Converts domain names into IP addresses • Without the DNS, the Internet would crash • One of the largest, distributed databases on the planet • Every domain name has a domain name server somewhere that handles its requests

  14. Internet Addresses • Address Scheme based on the DNS • Domain Name System • All Domain Names are converted to an IP address

  15. Do you know the IP address assigned to your computer • Windows 2000/XP • Click Start, Run • Type cmd to display the MS-DOS window • Type ipconfig and press [ENTER • Windows 98 • Click Start, Run • Type winipcfg

  16. Domain Name System

  17. E-MAIL • Sender Creates an e-mail message • SMTP software is responsible for routing the message out to the Internet • E-mail is received by SMTP software at the destination server • Transferred to a POP server • Read/Transferred to the recipients computer

  18. Additional LES Rules • Never send out E-Mail that you would not want to become public • Never send abusive, threatening, harassing or bigoted messages • Do not type in UPPERCASE. • This is called shouting and perceived to be offensive. • Use a normal mix of upper and lowercase letters • Think twice before sending E-Mail. You cannot get it back. • Personal notes should not sent via e-mail

  19. ISP,OSP,WSP • Internet Service Providers and Online Services • Have permanent connections to the Internet • Provide temporary connections to individuals and companies for a fee • Local and national ISPs • Online services offer members only areas (proprietary chats, research information, specialized material)

  20. Connecting • How do I choose one???? • Ask friends in your community if they are pleased with their ISP • Specifically you want to know these answers • Is it a local call to the ISP ? • What kind of set up charges are there - if any • Do they provide WEB page services (creating and editing). How much disk storage on their system are you given. What is the cost for additional space.

  21. Connecting • How long has the ISP been in business • Is there toll-free HELP -- what Days and Hours is it available • What is the ratio of subscribers to modems (10:1) is desirable;

  22. What are the options • POTS (Plain Old Telephone Services) • Cable • Dedicated Line • ISDN (Integrated Services Digital Network) • DSL ( Digital Subscriber Line) • T Lines, Most Pop – T1 • Satellite • Wireless

  23. Broadband Services • What does Broadband have to do with Internet access? • Measure of how fast data and information travel over transmission media • DSL • Provided by the phone company • Geographical limitations in obtaining DSL • Speed is affected by distance from the central switching office • Download is faster than upload • Go to http://www.cnet.com/internet/0-3762.html, type in your area code and select DSL residential it will give you speeds ( 1.5 Mbps) • Cable • Cable connection and a cable modem • Shared connection with neighborhood • At the above Intenet site, type in your zip code under Cable and it will give you speeds (500 kbps to 2 mbps )

  24. Tools of the Internet • E-Mail • Listservs • USENET News • FTP (File Transfer Protocol) • Telnet • WWW

  25. WWW • Developed in 1989 in Cern, Switzerland • Ability to link documents without a pre- defined menu system • Written in HTML (Hypertext Markup Language) • Mosaic…first graphical browser for Macs and PCs “We have to be careful”, Tim Berners-Lee warns, “because the sort of Web we end up …will be made by the decisions we make…the places we browse, the sites we setup and links we establish…..we have the answers in our hands”

  26. WWW Terminology • Client/Server • Browser/Server • Cookies • Intranet • Extranet • Homepage • Portal • HTML • HTTP • URL

  27. How do I change my Browser’s Homepage • IE • Click Tools on the menu bar • Click Internet options, general tab • Type in desired web address and click OK • Netscape • Click Edit on the menu bar • Select Preferences • Click Navigator • In Homepage box, type desired web address