The Internet and World Wide WebThe InternetHistory of the InternetSlide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10How the Internet WorksSlide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27The World Wide WebSlide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Web PublishingOther Internet ServicesSlide 52Slide 53Slide 54Slide 55The Internet and World Wide WebThe Internet andWorld Wide WebThe InternetWhat are some services found on the Internet? e-mail (1) Web (2) file transfer (3) e-mail (1) Web (2) file transfer (3) chat (4) message board (5) instant messaging (6) chat (4) message board (5) instant messaging (6)(1)(2)(3)(5)(4)(6)Goal:To function if part of network were disabledBecame functional September 1969Goal:To allow scientists at different locations to share informationHistory of the Internet How did the Internet originate? ARPANETNetworking project by Pentagon’s Advanced Research Projects Agency (ARPA)During the Cold War there was concern about connectivity in the event of a nuclear attack Early 1960’s Packet-switching envisioned (Baran and Davies) Divide a message into a smaller pieces called packets. Each packet contains where they came from and the address of where they are going. Each packet is sent to its destination separately. Provided the foundation for what became the Internet.History of the Internet ARPANET (Advanced Research Projects Agency NETwork) Funded by ARPA. Pooled computer scientists and resources from several universities. In 1969, linked 4 nodes at UCLA, UC Santa Barbara, SRI (Stanford Research Institute) and Univ. of Utah. By mid-1970’s, linked several military sites and about 20 universities.History of the Internet NSF (National Science Foundation) In 1980, started CSnet. Provided a resource sharing network for computer science research at all universities. Used TCP/IP protocol – the government gave it away – it is in the public domain – no charge for its use – UNIX based.History of the Internet In 1989, majority of ARPANET switched to NSF’s backbone. Became what is known as the Internet.  Early 1995, the Internet became known as the “Information Superhighway.”History of the InternetTodayMore than 100 million host nodesHistory of the InternetHow has the Internet grown?1984More than 1,000 host nodes1969Four host nodesGovernmentCable companiesSatellite companiesTelephone companiesWho provides the Internet’s structure today?Networks from corporations, commercial firms, and other companiesHistory of the InternetWorld Wide Web Consortium (W3C)•Oversees research, sets standards and guidelines•Tim Berners-Lee, directorInternet2 (I2)•Internet-related research and development project•Develops and tests advanced Internet technologiesWho controls the Internet?Nobody; it is public, cooperative, and an independent networkSeveral organizations set standardsHistory of the InternetHow the Internet WorksWhat are ways to access the Internet?1 Regional ISP2 National ISP3 OSP(Ex. AOL)4 Wireless Internet Service Providerlocal calllong-distance call1local call2local calltoll-free call3local call4Very high-speed connectionT-1, Fiber OpticHow can you connect to the Internet?Digital subscriber line (DSL) and cable modem Dial-up accessHow the Internet WorksBackbone(Communication Lines)How the Internet WorksWhat are three parts of an Internet connection?Client(Your computer)Server(Host computers)How might data travel the Internet using a telephone line connection?Step 1Step 1Step 2Step 1Step 2Step 3Step 1Step 2Step 3Step 4Regional ISPStep 1Step 2Step 3Step 4Step 5Regional ISPNational ISPStep 1Step 2Step 3Step 4Step 5Step 6Regional ISPNational ISPNational ISPInternet backboneStep 1Step 2Step 3Step 4Step 5Step 6Step 7Regional ISPLocal ISPNational ISPNational ISPInternet backboneHow the Internet WorksStep 1Step 2Step 3Step 4Step 5Step 6Step 7Step 8Regional ISPLocal ISPNational ISPNational ISPInternet backbone1: Request data from the a server on Internet.2: Modem converts digital signals to analog signals.3: Data travels through telephone lines to a local ISP.4: Data passes through routers.5: Regional ISP uses leased lines to send data to a national ISP.6: National ISP routes data across the country.7: National ISP passes data to local ISP.8: Server sendsdata back to you.Internet owes its original critical mass to the wide distribution of computers running the UNIX operating system.With the thousands of computers running the UNIX operating system, and freely distributed TCP/IP software suite:Original access to the Internet had UNIX “feel.”Exact addresses were needed to access information.Addresses were strings of numbersAddress for www.yahoo.com = 204.71.200.68You can find the Web server IP address by pinging the site at the DOS command prompt.UNIX gurus “ran the net.” They loved the degree of exclusivity due to the difficulty of use.This difficulty changed with development of “Gopher” and later the WWW.How the Internet WorksHow the Internet WorksWhat is an Internet protocol (IP) address?Number that uniquely identifies each computer or device connected to InternetIP address 199.95.72.10first part identifies networklast part identifies specific computerNetworks using the TCP/IP protocol route messages based on the IP address of the destination.Format of an IP address is a 32-bit numeric address written as four numbers separated by periods.Each number can be zero to 255. For example, 1.160.10.240 could be an IP address. An isolated network, you can assign IP addresses at random as long as each one is unique.Connecting a private network to the Internet requires using registered IP addresses (called Internet addresses) to avoid duplicates. The four numbers in an IP address are used in different ways to identify a particular network and a host on that network. How the Internet WorksThe InterNIC Registration Service assigns Internet addresses from the following three classes:Class A - supports 16 million hosts on each of 127 networksBeginning bit pattern 0 Class B - supports 65,000 hosts on each of 16,000 networks Beginning bit pattern 10