Internet Applications

Internet Applications Theory & Applications

Internet Applications - Ibrahim Otieno - iotieno@uonbi.ac.ke +254-0722-429297 SCI/ICT Building 2nd Floor Rm. 201

ICS 622 - Delivery • ±48 contact hours • 4 hours a week • Monday5:30- 8:30 pm • Thursday 5:30 - 7:00 pm • Assessment • CAT • Assignment • Exams • Theoretical course, but • Interactive • Exercises (reflect exam questions)‏ • Laboratory sessions

ICS 622 - Delivery • Online access to course materials: • Notes • Slides • Assignments • Announcements • http://learning.uonbi.ac.ke • Login: • Username: registration number (P58/10202/2010)‏ • Password: msc

ICS 622 – Course Text • Douglas Commer, Computer Networks and Intranets, (New Jersey, Prentice Hall) • Deitel and Deitel, Internet and World Wide Web How to Program, Prentice Hall • E. Loren Buhle et. Al., Webmasters's Professional Reference, (New Riders Publishing) • Scott Hillier and Daniel Mezick, Programming Active Server Pages, (Washignton, Microsoft press)

Course Outline • History of the Internet • Internet Protocols • Internet & Communication protocols • Internetworking • TCP/IP Applications • Web Application Design & development • Web site Administration and Internet Security • Cloud Computing

Objectives • To describe the Internet Technology • To appreciate the development of the Internet • To understand the theory, role and applications of the Internet • To develop Web Applications

Introduction • What is the Internet? • What protocols are used? • What is a computer network? • Interconnected, communicating and sharing data • Types of Computer Networks? • LAN, CAN, MAN, WAN

Introduction • Network Topologies? • Star, Bus, Ring • Technologies in WAN • Circuit switching, Packet switching • Internet, Intranet and extranet

TCP/IP Overview • Network protocolsare formal rules of behavior that govern network communication • Specifies format and meaning of messages • Set of related protocols designed for compatibility referred to as protocol suite. • Transmission Control Protocol (TCP) and Internet Protocol (IP) are two communication protocols encompassed byInternet Protocol Suite

TCP/IP Overview • Protocol suite referred to as TCP/IP as TCP & IP are two most important protocols of collection • Other protocols include: UDP, ICMP, FTP, HTTP • TCP/IP has a set of standards specifying how computers communicate and how routing is done through the interconnected computers • Provides two primary services: connectionless packet delivery and reliable stream transport

TCP/IP Overview …cont’d TCP/IP has been made popular because of these features: • Network Topology Independence- TCP/IP is used on bus, ring, and star networks. It’s used in LANs as well as WANs • Physical Network Hardware Independence- TCP/IP can utilize Ethernet, token ring, or any number of physical hardware variations.

TCP/IP Overview …cont’d • Open Protocol Standard- The TCP/IP protocol suite standard is freely available for implementation on any platform (H/W & O/S). • Universal Addressing Scheme- Each computer on a TCP/IP network has unique address enabling any TCP/IP enabled device to communicate with it. • Powerful Client-Server Framework- TCP/IP is the framework for powerful and robust client-server applications that operate in LANs and WANs

The Internet • Internet is a worldwide system of interconnected computers and computer networks that use the TCP/IP protocol suite • Internet is a network of networks, linking computers to computers sharing the TCP/IP protocols. Each runs software to provide information and/or to access and view information • At a basic level Internet is a global computer of networks, that allows millions of machines to communicate with each other

The Internet • Internet is a worldwide tele-communications system that provides connectivity for thousands of other smaller networks; therefore, often referred to as a network of networks • The Internet is a worldwide network of thousands of linked computers compared to "a giant international plumbing system" • The Internet is actually millions of computers connected together in some way (phone lines, Ethernet, ISDN, cable modems) so that they can share information.

The Internet …cont’d Packets/ Headers/ Routing/ Error Correction/ Reassembly

The Internet …cont’d • The metaphor of roads: • Side roads run through neighborhoods, linking different parts, linking individual building together • Small roads in turn connect to large ones • Each building is a different computer on the internet with it own function - government offices, educational institutions etc.

The Internet …cont’d • The metaphor of roads: • Roads are network connections that link buildings together. Vehicles travelling along them are data • Data can be sent from one computer to another no matter where they are physically • Note: Internet is not just one gigantic computer with all of the information;

The Internet …cont’d • Compared to international communication utility servicing computers • Nodes connected through routers "gateways", and share a common name and address space • Internet is revolutionizing communication and changing the way we work and play • Internet is transport vehicle for info stored in files or documents on other computers

The Internet …cont’d • By 1993, Internet included 10,000 IP networks interconnecting more than 1m computers and millions of users • The Internet itself does not contain information • Misstatement - "document found on the Internet." • Correct - found through or using the Internet • Found in/on one of computers on the Internet

History of the Internet • 1957: The USSR launches Sputnik, first artificial earth satellite. • US forms the Advanced Research Projects Agency (ARPA) within the DoD to establish US lead in science and technology applicable to the military • 1962: J.R. Licklider of MIT, propose a global network of computers. Leonard Kleinrock of MIT and later UCLA developed the theory of packet switching

History of the Internet • 1962: Paul Baran, of RAND Corporation commissioned by the U.S. Air Force to do a study on how it could maintain its command and control over its missiles and bombers, after a nuclear attack • His final proposal was a packet switched network: • Packet switching is breaking of data into packets • Labeled to indicate the origin & the destination • Forwarding of packets from one computer to another computer to its final destination computer • If packets lost, message can be resent by originator

History of the Internet …cont’d • 1968: ARPA awarded ARPAnet contract to BBN • BBN selected a Honeywell mini-computer as base on which they would build the switch • Physical network constructed in 1969, linking four nodes: University of California at Los Angeles, SRI (Stanford), University of California at Santa Barbara, and University of Utah.

History of the Internet …cont’d • 1972: First e-mail program created by Ray Tomlinson of BBN. • ARPA renamed to DARPA. • ARPANET was using NCP to transfer data • Communications between hosts on same network • 1973: Development began on TCP/IP • Developed by a group headed by Vinton Cerf from Stanford and Bob Kahn from DARPA. • Protocol was to allow diverse computer networks to interconnect and communicate with each other

History of the Internet …cont’d • 1974: First use of term Internet by Vint Cerf and Bob Kahn in paper on TCP • 1976: Robert M. Metcalfe develop Ethernet, which allowed coaxial cable to move data fast • Crucial component to development of LANUUCP (Unix-to-Unix CoPy) developed at AT&T Bell Labs and distributed with UNIX one year later • DoD began to experiment with TCP/IP and decided to require it for use on ARPANET

History of the Internet …cont’d • 1979: USENET based on UUCP created by Steve Bellovin • Creation of BITNET, by IBM, "Because its Time Network", introduced "store and forward" n/w • Used for email and listservs • 1981: NSF created backbone called CSNET for institutions without access to ARPANET • 1983: Internet Activities Board (IAB) created. January 1st , every machine connected to ARPANET had to use TCP/IP replacing NCPUniversity of Wisconsin created DNS • Allowed packets to be directed to domain name making it easier for people to access servers

History of the Internet …cont’d • 1984: ARPAnet divided into two networks: MILnet and ARPAnet • DoD continued to support both networks • 1985: NSF began deploying its new T1 lines, which would be finished by 1988 • 1986: IETF was created to serve as a forum for technical coordination by contractors for DARPA working on ARPANET, US Defense Data Network (DDN), and the Internet core gateway system.

History of the Internet …cont’d • 1987: BITNET and CSNET merged to form the Corporation for Research and Educational Networking (CREN), another work of NSF • 1991: CSNET was discontinued having fulfilled its important early role in the provision of academic networking service • 1992: Internet Society is chartered and WWW released by CREN.

History of the Internet …cont’d • 1993: InterNIC created by NSF to provide specific Internet services: directory, database, registration, and information servicesMarc Andreessen, NCSA and University of Illinois develops a GUI to the WWW, called "Mosaic". • 1994: The most significant thing was growth. Pizza Hut offers pizza ordering on its Web page and the first cyberbank, opens.ATM (Asynchronous Transmission Mode) backbone is installed

History of the Internet …cont’d • 1996-DATE: Internet traffic carried by backbones of ISPs, including MCI, AT&T, Sprint, UUnet, BBN planet, ANS, and more.Currently Internet Society(ISOC) is the group that controls devpt and availability of internet • Trying to figure out new TCP/IP to be able to have billions of addresses, rather than the limited system of today Problem is that not known how both old and new addressing systems will work at the same time during a transition period

Internet Usage • Number of users has grown from an estimated 38m in 1994 to 101m in January 1998 and over 400m in December 2000, 580m in May 2002 and 1.6 b in June 2009 and 2 b in 2011. Distribution of Internet Users (millions) (178M Sites) Dec 2000 May 2002 • USA/Canada 177.78 (42.5%) 182.67 (31.4%) • Europe 133.97 (32.0%) 185.83 (32.0%) • Asia/Pacific 104.88 (25.1%) 167.86 (28.9%) • Latin America 16.45 (3.9%) 32.99 (5.7%) • Africa 3.11 (0.7%) 6.31 (1.1%) • Middle East 2.40 (0.6%) 5.12 (0.9%) TOTAL 418.59 580.78

Internet Usage

Uses of the Internet • Email and Mailing Lists E-mail – allows "mailing electronic" messages LISTSERVs - special mailing lists allowing exchange of info between large groups of people According IDC, on an average day in 2000, 5.1 b emails are sent in the US and 8.2 b worldwide • Telnet Connection to remote hosts • FTP and File Sharing Used to place variety of information online Originally text only e.g. Kazaa, Napster, Emule

Uses of the Internet …cont’d • Newsgroup, User group & Bulletin Boards USENET - system of special interest discussion groups to which readers can "post" messages that are distributed to other computers Newsgroups organized around specific topics • Website Browsing with World Wide Web World Wide Web (WWW or the Web) -interesting to people because it includes pictures and sounds.

Uses of the Internet …cont’d • Chatting & SMS (MSN, Yahoo) Like telephone, Internet allows you to "chat" with people by participating in online discussion groups • News and Information Dissemination Like newspaper, the Internet can give you new information every day, including world news, business, sports, travel, entertainment, and ads • Libraries and Research Like library, Internet contains information on any topic you can imagine in many formats, including books, articles, videos, and music recordings • Search Engines There are several search engines including: Yahoo, Google, Altavista, Infoseek, Lycos, Hotbot…

Uses of the Internet …cont’d • Entertainment Streaming Media (Video/ Radio), Games, Novels • Internet Telephony • E-commerce (Amazon, Ebay, Walmart) Advertising, Shopping & Business Processes Internet Banking/ Auctions/ Lotteries/ Gambling Customer Care and User Support • Video Conferencing & Communication • E-learning, Open and Distance Learning Professional courses & Degrees

Dangers of the Internet • Internet use catching on faster than any form of technology ever invented • Its potential for human benefit is beyond measure, but it is not without problems: • Marriages break up over “e-relationships” • Students risk health/grades to spend time online • Child abusers lure kids through the internet • Adults spend fortunes to subscribe pornography • Internet fraud and Cyber crime is here and now • Users have crossed boundary between healthy use & obsessive preoccupation with the internet

Dangers of the Internet ..cont’d • Exposure to Inappropriate material Children, youth and the “tempted” Hate messages, violence and sexual material, jokes on physical violence, assaults, aggression, and exchange involving racial prejudice Chat rooms and messages on sexual advances

Dangers of the Internet ..cont’d • Hazards of real life Meetings: • Research in Thailand indicated: 24% of children and 37% of youths had at least one 'physical' meeting with someone they had only communicated with online 42% of children said that they would like to meet their virtual friends at some point Majority surprised by the identity of the person and at times the surprise was a nasty shock • Creation of unhealthy new relationships and identities

Dangers of the Internet ..cont’d • Unwanted Distribution of Personal Info • Sale of mailing lists and address information… • Physical address posing danger from molesters • Credit card information • Passwords • Negative Language development F2F - face to face, TNSTAAFL, there’s no such thing as a free lunch FYI - for your information IMHO - In my humble/honest opinion, TTFN Ta Ta for now, BRB - be right back BTW - by the way

Dangers of the Internet ..cont’d • Fraud and Identity Theft "Credit identity theft“ means theft of consumer's personal and credit information which a thief uses to gain access to victim's credit & bank accounts Personal identification information that is available on the Internet can be accessed by anyone and misused to obtain credit in the victim's name

Dangers of the Internet ..cont’d • Adverts, Spam, Junk and unsolicited Mail The average user now receives 81 e-mails each day, and nearly one quarter of them are spam "As long as people buy the products, I'll keep sending mail," says Ron Scelon, a self-described "spammer," he runs Scelon Marketing, which sends up to 100 million unsolicited e-mails a day

Dangers of the Internet ..cont’d • Cyber-Terrorism (Hacking) Hacking is simply, asking a lot of questions and refusing to stop asking They don't tell you to shut up for asking questions / inputting commands over and over Hacking is unauthorized use of computer and network resources Threats to shutdown Internet!

Dangers of the Internet ..cont’d • Internet as a Health hazard Some 300K of Taiwan's 6 m Internet users may be sufferers of a condition known as Internet Addiction Disorder (IAD) IAD is defined as a psycho-physiological disorder involving tolerance of long online hours, withdrawal symptoms (anxiety and depression) and a failure to regulate daily Internet use, resulting in impairment of relationships 5% of users are "possible sufferers" of IAD

Dangers of the Internet ..cont’d • Computer Viruses, Worms & Trojans The issue of hoaxes • Hook, Threat and Request • "send this to everyone you know" Necessary condition to be considered a virus is: • Capability to produce copies of itself • Incorporate itself into computer networks and/or files, system areas of computers, and other executable objects • Copies maintain capability to spread further

Internet Applications