Internet Applications Theory & Applications. Internet Applications - Ibrahim Otieno - [email protected] +254-0722-429297 SCI/ICT Building 2 nd Floor

Internet Internet ApplicationsApplications

Theory & Applications

Internet Applications

- Ibrahim Otieno -

[email protected]

+254-0722-429297

SCI/ICT Building 2nd Floor Rm. 201

ICS 622 - DeliveryICS 622 - Delivery ±48 contact hours 4 hours a week

Monday 5:30 - 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 - DeliveryICS 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 TextICS 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 OutlineCourse OutlineHistory of the Internet Internet Protocols Internet & Communication

protocols InternetworkingTCP/IP ApplicationsWeb Application Design &

developmentWeb site Administration and

Internet SecurityCloud Computing

ObjectivesObjectives

To describe the Internet TechnologyTo appreciate the development of

the InternetTo understand the theory, role and

applications of the Internet To develop Web Applications

IntroductionIntroduction

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

IntroductionIntroduction

Network Topologies?◦Star, Bus, Ring

Technologies in WAN ◦Circuit switching, Packet switching

Internet, Intranet and extranet

TCP/IP OverviewTCP/IP OverviewNetwork protocols are 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 by Internet Protocol Suite

TCP/IP OverviewTCP/IP OverviewProtocol 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’dTCP/IP Overview …cont’dTCP/IP has been made popular because of these features:

1.Network Topology Independence - TCP/IP is used on bus, ring, and star networks. It’s used in LANs as well as WANs

2.Physical Network Hardware Independence - TCP/IP can utilize Ethernet, token ring, or any number of physical hardware variations.

TCP/IP Overview …cont’dTCP/IP Overview …cont’d3. Open Protocol Standard - The TCP/IP

protocol suite standard is freely available for implementation on any platform (H/W & O/S).

4. Universal Addressing Scheme - Each computer on a TCP/IP network has unique address enabling any TCP/IP enabled device to communicate with it.

5. Powerful Client-Server Framework - TCP/IP is the framework for powerful and robust client-server applications that operate in LANs and WANs

The InternetThe 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 InternetThe 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’dThe Internet …cont’d

Packets/ Headers/ Routing/ Error Correction/ Reassembly

The Internet …cont’dThe 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’dThe 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’dThe 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’dThe 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 InternetHistory 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 InternetHistory 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 …History of the Internet …cont’dcont’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.


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


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 LAN

UUCP (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


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


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.


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.


1993: InterNIC created by NSF to provide specific Internet services: directory, database, registration, and information services

Marc 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 …History of the Internet …cont’dcont’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 UsageInternet 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 UsageInternet Usage






Uses of the InternetUses of the Internet Email and Mailing Lists

E-mail – allows "mailing electronic" messagesLISTSERVs - special mailing lists allowing exchange of info between large groups of peopleAccording 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 SharingUsed to place variety of information onlineOriginally text only e.g. Kazaa, Napster, Emule

Uses of the Internet …Uses of the Internet …cont’dcont’d

Newsgroup, User group & Bulletin BoardsUSENET - 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 WebWorld Wide Web (WWW or the Web) -interesting to people because it includes pictures and sounds.

Uses of the Internet …Uses of the Internet …cont’dcont’d

Chatting & SMS (MSN, Yahoo)Like telephone, Internet allows you to "chat" with people by participating in online discussion groups

News and Information DisseminationLike newspaper, the Internet can give you new information every day, including world news, business, sports, travel, entertainment, and ads

Libraries and ResearchLike library, Internet contains information on any topic you can imagine in many formats, including books, articles, videos, and music recordings

Search EnginesThere are several search engines including:Yahoo, Google, Altavista, Infoseek, Lycos, Hotbot…

Uses of the Internet …Uses of the Internet …cont’dcont’d Entertainment

Streaming Media (Video/ Radio), Games, Novels

Internet Telephony

E-commerce (Amazon, Ebay, Walmart)Advertising, Shopping & Business ProcessesInternet Banking/ Auctions/ Lotteries/

GamblingCustomer Care and User Support

Video Conferencing & Communication

E-learning, Open and Distance LearningProfessional courses & Degrees

Dangers of the InternetDangers 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 Dangers of the Internet ..cont’dInternet ..cont’d Exposure to Inappropriate

materialChildren, youth and the “tempted”Hate messages, violence and sexual material, jokes on physical violence, assaults, aggression, and exchange involving racial prejudiceChat rooms and messages on sexual advances

Dangers of the Dangers of the Internet ..cont’dInternet ..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 online42% of children said that they would like to meet their virtual friends at some pointMajority 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 Dangers of the Internet ..cont’dInternet ..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 developmentF2F - face to face, TNSTAAFL, there’s no such thing as a free

lunchFYI - for your informationIMHO - In my humble/honest opinion, TTFN Ta Ta for now, BRB - be right backBTW - by the way


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


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 Dangers of the Internet ..cont’dInternet ..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 Dangers of the Internet ..cont’dInternet ..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


Computer Viruses, Worms & TrojansThe 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

Suggested SolutionsSuggested Solutions1. Educating adults and children about Internet 2. Role of the Church… who pastors the Pastor?3. Absentee “parent”4. Legal Approach: Laws & the Web Police5. Economic Controls: Make expensive to send

email6. Advert blocking, Anti-Spam & Junk buster s/w7. Filters that block access to sites or chat rooms8. Refuse connections from known offenders9. Use of secure browser that encrypts

information

Documents

Internet Applications Theory & Applications. Internet Applications - Ibrahim Otieno - [email protected] +254-0722-429297 SCI/ICT Building 2 nd Floor