1 INTERNET AND WORLD WIDE WEB TECHNOLOGIES BUS Abdou Illia, Spring 2007 (Week 11, Thursday 3/22/2007)

2 LEARNING GOALS  Identify and describe the major Internet applications.  Define the World Wide Web and its operation.  Define intranets and extranets and explain how companies use them.

3 Test your Internet knowledge (1) This week we saw that a network can be set in order to share software resources (like data files, databases, and programs) and hardware resources (like printers). In other words, we can say that a network can be set to provide file service, database service, and print service to users. Based on your Internet experience what kind of services users can get from the Internet? .

4 Brief history of the Internet 1969The Defense Advanced Research Projects developed ARPANET, the precursor of the Internet 1971Ray Tomlison invents 1979USENET newsgroups created at Duke University and the University of North Carolina 1984Domain Name System (DNS) established 1991Tim Berners-Lee creates the World Wide Web 1994First online shopping mall, first spam , first pizza ordered online, first advertisement banner 2000A major denial of service attack brings down websites such as Yahoo!, Amazon.com, and eBay 2002Denial of service attack knocks out 8/15 root DNS servers

5 Test your Internet knowledge (2) Based on your Internet experience what are the different types Internet connections a residential user or a business can subscribe for? .

6 Accessing the Internet

7 Webserver needs: - Network Operating System - TCP/IP - Domain name (e.g. eiu.edu) - Internet access - IP Address (e.g ) User PC needs: - Workstation Operating System - TCP/IP - Web browser (e.g. Internet Explorer) - Internet access (e.g. thru an ISP) - IP Address (e.g ) Accessing the Internet (www) Network Web Browser Packet Router Packet Route Webserver Software 7

8 IP Address  A number that uniquely identify a computer connected to the Internet  Four decimal numbers separated by dots  Example:

9 Domain name  Like a nickname given to a server  Two or more text “labels” separated by dots  Easier to remember compared to IP address microsoft.com eiu.edu sales.microsoft.com

10 Domain Name System (DNS)  System for searching IP addresses based on domain names

11 Domain Name System (DNS)

12 Internet applications/services   File transfers  Instant messaging (IM)  Newsgroups  Streaming audio and video  Internet telephony  World Wide Web (WWW)

13  Most popular and widely used Internet application  30 billion s sent every day Spam – junk messages Spam costs corporate America $9 billion per year  Every message contains head that describes source and destination for the message  messages are text, but may have attachments of many types of digital data Viruses often transmitted via

14 File Transfers  File transfer protocol (FTP) Protocol providing for transmission of a file between an Internet server and a user’s computer  Peer-to-peer (P2P) file sharing Share data from one computer to another Every user can be a server and a client With P2P, every user on the network can make data available to every other user on the network Examples of P2P File transfer systems:  Napster  Kazaa  Gnutella  Limewire

15 Instant Messaging  Allows user to create a private chat session with another user  IM started with AOL  Many Web-based companies use IM technology for customer service State of Virginia eBay

16 Usenet Newsgroups  Online, bulletin board discussion forums  Users post and read messages  More than 100,000 newsgroups  Millions of newsgroup readers  Important information resource, especially for technical issues and products

17 Streaming Audio and Video  Creating and sending audio and video files Sports  Men’s intercollegiate basketball at sports.yahoo.comsports.yahoo.com  Major league baseball Major league baseball News  Fox News Fox News  CNN radio CNN radio Business  ZDNet ZDNet Education  Warriors of the Net Warriors of the Net General  Youtube.com Youtube.com  Also known as Podcasting

18 Internet Telephony  Uses Voice-over Internet Protocol (VoIP)  Can use your computer to make phone calls  Software connects computers via the Internet and transmits voice data  Savings comes from eliminating toll charges between locations

19 Intranets and Extranets  Intranet Internal company network that uses Internet and WWW technologies. Typical Use:  Finding and sharing work documents  Collaboration between employees to work in teams  Communication tool Only authorized users can get access  Secured by firewall  Extranet Web site that allows customers and business partners limited access to organizational intranet Uses Internet and WWW technologies Add additional security through the use of a Virtual Private Network (VPN) Virtual Private Network

20 Summary Questions MalagaNotes 1)(a) Name some Internet applications/services (b) What is Instant Messaging? (c) What is a newsgroup? 12, 15, 16 2) (a) What does a user PC needs for accessing the World Wide Web? (b) What is needed on the webserver side? 7 3)Name some Internet connection options available for residential users and businesses )(a) What is a domain name? (b) What is Domain Name System or DNS? )(a) What is an intranet? (b) What is an extranet? 19