Introduction to Internet

Presented

by

Sameera Kishore

A Brief History of InternetA Brief History of Internet

Started by the Department of Started by the Department of Defense, was called the ARPANET Defense, was called the ARPANET project in 1969.project in 1969.

The Internet is the largest The Internet is the largest computer computer network network in the world, connecting in the world, connecting millions of computers. A millions of computers. A networknetwork is is a group of two or more computer a group of two or more computer systems linked together.systems linked together.

Internet Growth TrendsInternet Growth Trends

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 hostsBy 2010, about 80% of the planet will be on the Internet

EMAIL

DEFINITIONS

ABUSE

CONNECTING TO

INTERNET

INTERNET

NARROW BAND BROAD BAND

CONNECTING TO INTERNET

An ISP may offer either narrow band or broad band connection (or both).

Band width refers to the amount of data that can be sent via modem or network connections measured in bits–per-second.

YearYear Broad band Broad band UsersUsers

Narrow band Narrow band UsersUsers

March ’06March ’06 68%68% 32%32%

Jan ‘05Jan ‘05 55%55% 45%45%

Simple Mail Transfer Protocol ( SMTP ) : It is the protocol used to send email messages from one server to another.

Post Office Protocol ( POP3 ): It stores the messages for the recipient. To retrieve the messages, the user must connect to it using email client or the online email service

IMAP: It enables a user to check email from multiple computers at different locations.

You need broadband to:You need broadband to:

Watch videos on Net.Watch videos on Net. Faster Uploads.Faster Uploads. Voice over IP.Voice over IP. Video conferencing.Video conferencing. Send and Receive large files.Send and Receive large files. Get Online FasterGet Online Faster

File DownloadFile Download Dial-upDial-up BroadbandBroadband

Digital image (.5 MB)Digital image (.5 MB) 1.5 mins1.5 mins 5 seconds5 seconds

Video Clip ( 1 MB)Video Clip ( 1 MB) 2.5 mins2.5 mins 11 seconds11 seconds

MP3 file ( 4MB ) MP3 file ( 4MB ) 9.9 mins9.9 mins 47 seconds47 seconds

Upgrade Software ( 25 Upgrade Software ( 25 MB )MB )

62.4 mins62.4 mins 5 mins5 mins

DEFINITIONSDEFINITIONS

DOMAIN NAMEDOMAIN NAME DOMAIN NAME SYSTEM ( DNS )DOMAIN NAME SYSTEM ( DNS ) FILE TRANSFER PROTOCOL (FTP)FILE TRANSFER PROTOCOL (FTP) HYPERTEXT TRANSFER PROTOCOL ( HTTP ) HYPERTEXT TRANSFER PROTOCOL ( HTTP ) HYPERTEXT MARKUP LANGUAGE ( HTML ) HYPERTEXT MARKUP LANGUAGE ( HTML ) UNIFORM RESOURCE LOCATOR ( URL ) UNIFORM RESOURCE LOCATOR ( URL ) SIMPLE MAIL TRANSFER PROTOCOL ( SMTP )SIMPLE MAIL TRANSFER PROTOCOL ( SMTP ) POST OFFICE PROTOCOL ( POP ) POST OFFICE PROTOCOL ( POP )

WHAT HAPPENS WHEN WE – EMAIL ?!?!WHAT HAPPENS WHEN WE – EMAIL ?!?!

An email is a text message sent to a recipient using email clients such as Microsoft outlook, Juno client or online email services such as Yahoo &Gmail.

DOMAIN NAME SYSTEM (or Service or Server)DOMAIN NAME SYSTEM (or Service or Server) It is the way that internet domain names are located and It is the way that internet domain names are located and

translated to IP addressestranslated to IP addresses . .

domain namedomain name Names used in URL's and corresponding to one or more IP Names used in URL's and corresponding to one or more IP

addresses. addresses. The basic purpose of domain name is to provide easily The basic purpose of domain name is to provide easily

recognizable names to the numerically addressed internet recognizable names to the numerically addressed internet resources resources

What is a Fully Qualified Domain Name ?

example: www.maps.google.com

Top Level Domain

User Specific Domain

Sub Domain

File Transfer Protocol (FTP)File Transfer Protocol (FTP)

A common protocol that facilitates transferring any type of A common protocol that facilitates transferring any type of electronic files over the Web.electronic files over the Web.

Hypertext Transfer Protocol (HTTP) The protocol computers use to transmit Web documents between computers, identified by the prefix "http://" of the URL.

Internet Protocol (IP Address ) The numerical identifier for a computer connected to a TCP/IP network, such as the Internet.

Uniform Resource Locator ( URL )Uniform Resource Locator ( URL ) It specifies the address of a web page. It specifies the address of a web page. e.g: http://www.example.net/e.g: http://www.example.net/

ABUSE

SPAM SCAM VIRUS

Is your computer spewing SPAM????

Spam or Spamming is the abuse of electronic messaging systems to indiscriminately send unsolicited messages.

Email Spam is the practice of sending unwanted email messages frequently with commercial content, in large quantities to an indiscriminate set of recipients.

EMAIL SPAM

Unsolicited Bulk Email Unsolicited Commercial Email

Examples of SPAMExamples of SPAM Make money Fast Chain Letters Make money Fast Chain Letters

Spam.Spam. A-pound a- day diet Spam.A-pound a- day diet Spam. Just Read this ! Spam's containing Just Read this ! Spam's containing

long, winding messages.long, winding messages. Fake Anti Spam Sites.Fake Anti Spam Sites.

Fight against SPAMFight against SPAM

• Coalition Against Unsolicited Commercial E mail ( CAUCE ).• National Fraud Information Center (NFIC)• www.spambusters.org

Scams are emails cleverly disguised as coming from real companies when they are actually trying to know your private information such as passport number, bank account, social security number etc. Again, it is one of the most common problems faced by Internet users.

Phisher scamsPhisher scams Lottery scamsLottery scams Nigerian Nigerian scamsscams

Work-at-home Work-at-home scamsscams

VIRUS: A computer virus is a small piece of software that attaches itself to a program or a file enabling it to spread from one computer to another

HOW DO I KNOW IF THE COMPUTER HAS VIRUS?!?!

The computer runs slower than usual.The computer stops responding or locks up frequentlyThe computer restarts on its own.Applications on the computer so not work correctly or are inaccessible.It shows unusual error messages.It shows distorted menus and dialog boxesAn antivirus program is disabled for no reason, and it cannot be restarted.A program disappears from your computer.Strange sounds play from the speaker unexpectedlyNew icons appear on the desktop

E.g. of Virus: Melissa. A, Anti EXE, Trj.Reboot, Word Concept.

WORMWORM A worm is a self-replicating computer program or software A worm is a self-replicating computer program or software

applications designed to spread via networks. It uses a network to applications designed to spread via networks. It uses a network to send out copies of itself.send out copies of itself.

Examples of Worm:

• Nuwar OL Worm- Nuwar OL is delivered to a user's inbox with subjects like "You Are In My Dreams," "I Love You So Much," "Inside My Heart Is You," etc. To disguises its activity, the worm redirects you to simple web page with the theme of a romantic greeting card. Once the computer is infected, the infection spreads by sending messages to names in the user's contact folder.

•Valentin E Worm- It is also distributed via email. This worm also includes an attached file called ‘friends4U’. When the user opens the attachment, a copy of the worm gets downloaded onto their computer

Trojan HorseTrojan Horse

Trojan horse is a destructive program that disguises itself as Trojan horse is a destructive program that disguises itself as a real application. a real application.

This is a type of virus that attempts to make the user think This is a type of virus that attempts to make the user think that it is a beneficial application. that it is a beneficial application.

Well-known Trojan horses:Back Orifice

Back Orifice 2000Netbus

SubsevenDownloader- EV