Tim Berners-Lee was the man leading the development of the World Wide Web , the defining of HTML -used to create web pages, HTTP and URLs (Universal Resource Locators).
Internet “ The internet is a network of networks---a global communications system that links together thousands of individual networks”.
1968 - DARPA (Defense Advanced Research Projects Agency) contracts with BBN (Bolt, Beranek & Newman) to create ARPAnet
1969- Arpanet (advance research project agency ).
The BBN design this network for united states department of defense.
The military develop the ARPANET in response to the threat of a nuclear attack that might destroy the country’s communication system.
The ARPA was primarily used by the military.
Some of the large companies such as IBM, and universities.
The general population was not yet connected to the system.
Very few people were on line on network.
Twenty Three Nodes, 1972
The ARPA was international
With nodes in Europe at the university college in London, and royal radar establishment in Norway.
RAY Tomlinson, invented E-mail, Who worked at BBN.
At &T BELL labs developed UNIX to UNIX copy. 1977, UUCP was distributed with UNIX.
User network (USENET) was started by using UUCP to connect Duke university and the university of north Carolina at chapel hill. News groups emerged from this early development.
Transmission protocol/Internet protocol (TCP/IP), a set of governing how networks making up the ARPANET communicate was established.
As the internet grew the domain name system (DNS) was developed.
The computer science network (CSNET) connected all university computer science department in the united states.
CSNET joined the ARPANET in 1981.
The because its Time Network formed at the university of new York and connected to Yale university.
The united states defense communications agency required that TCP/IP be used for all ARPANET hosts.
Since TCP/IP was distributed at no charge.
This allow the internet to grow quickly as all connected computers were now speaking g the same language.
World Wide Web 1991
The World wide web created by Tim Berners –Lee.
As a simple way to publish information and make it available on the internet.
The WWW publicly available In 1992
Mosaic a graphical browser for the web, released by Marc Andreessen and several other students at the university of Illinois.
Netscape Communication 1994
The company called the Netscape Communications, by Marc Andreessen and Jim Clark, released Netscape Navigator, a web browser that captured the imagination of everyone who use it.
Microsoft discovers the Internet, 1995
Internet courses offers by colleges, 1995
Over 55 Million Nodes, 1999
“ I LOVE YOU” Virus, 2000
Wireless Devices, 2001
WORLD INTERNET USAGE AND POPULATION STATISTICS 219.8 % 100.0 % 17.6 % 1,154,358,778 WORLD TOTAL 146.7 % 1.6 % 54.5 % 18,796,490 Oceania / Australia 508.6 % 9.5 % 19.8 % 109,961,609 LatinAmerica/ Caribbean 115.2 % 20.2% 69.5 % 232,655,287 North America 494.8 % 1.7 % 10.1 % 19,539,300 Middle East 206.2 % 27.9% 39.8 % 321,853,477 Europe 265.7 % 36.2 % 11.3 % 418,007,015 Asia 643.1 % 2.9 % 3.6 % 33,545,600 Africa Usage Growth 2000-2007 Usage % of World % Population ( Penetration ) Internet Usage, Latest Data World Regions
Internet Usage in Asia 66.30% 2,421,800 1,200,000 3,654,103 Singapore 68.20% 4,878,713 2,283,000 7,150,254 Hong Kong * 12.50% 8,420,000 2,300,000 67,249,456 Thailand 7.20% 12,000,000 133,900 167,806,831 Pakistan 47.80% 13,528,200 3,700,000 28,294,120 Malaysia 16.00% 14,000,000 2,000,000 87,236,532 Philippines 63.00% 14,500,000 6,260,000 23,001,442 Taiwan 18.50% 15,760,702 200,000 85,031,436 Vietnam 8.90% 20,000,000 2,000,000 224,481,720 Indonesia 66.50% 34,120,000 19,040,000 51,300,989 Korea, South 3.70% 42,000,000 5,000,000 1,129,667,528 Ind i a 67.10% 86,300,000 47,080,000 128,646,345 Japan 10.90% 144,000,000 22,500,000 1,317,431,495 China -- -- -- 23,510,379 Korea, North 1.10% 300,000 - 27,089,593 Afganistan (% Population) Latest Data (Year 2000) ( 2007 Est.) Penetration Internet Users, Internet Users, Population ASIA
How Do You Get On The Internet
You need three items to get on the Internet:
A computer to surf the Internet with
An Internet Service Provider (ISP) to provide access to the Internet
A modem or router to hook up your computer to the Internet via the ISP
Also Recommended( ! )
While not technically necessary it is highly recommended your computer also have the following when hooked up to the Internet:
Latest Updates To Your Operating System
Your Internet Service Provider may be able to help with these
Today’s Goal: Internet Services
To look at several services provided by the Internet
WWW ( Web)
But first, we need to find out about the addressing scheme used on the Internet
Regular post cannot be delivered unless we write a destination address on the envelope
Same is true for the Internet
Regular post can be delivered at the intended address even if the given address is not precise . That is not the case for Internet addressing
22.214.171.124 www.vu.edu.pk IP address DNS address
IP Address (1)
A unique identifier for a computer on a TCP/IP network
Format: four 8-bit numbers separated by periods. Each 8-bit number can be 0 to 255
126.96.36.199 (IP address of the VU Web server)
server ? client
IP Address (2)
Networks using TCP/IP route messages based on the IP address of the destination
Any IP addresses (as long as they are unique ) can be assigned within a PN
However, connecting a PN to the Internet requires using unique, registered IP addresses
IP addresses are fine for computers, but difficult to recognize and remember for humans
A domain name is a meaningful, easy-to-remember ‘label’ for an IP address
DNS: Domain Name System (1)
DNS is the way that Internet domain names are located & translated into IP addresses
Maintaining a single, central table of domain name/IP address relationships is impractical
Billions of DNS-IP translations take place every day
The DNS-IP tables get updated continuously
DNS: Domain Name System (2)
Tables of DNs & IP addresses are distributed throughout the Internet on numerous servers
There is a DNS server at most ISPs . It converts the domain names in our Internet requests to actual IP addresses
In case it does not have a particular domain name in its table, it makes a request to another DNS server on the Internet
There are many, but we will look at only the following:
WWW ( Web)
FTP: File Transfer Protocol
Used to transfer files between computers on a TCP/IP network (e.g Internet)
The files are stores on special types of server called the ftp server.
The browser can be use to transfer files from ftp server to the client computer but it is slow process to transfer files.
A lot of ftp client program of different software companies are available through which files can be download from ftp server into to your local computer very easily and quickly. Similarly the files from your commuter can be uploaded to the ftp server. These special programs are WS_FTP and cute FTP.
Simple commands allow the user to:
List, change, create folders on a remote computer
Upload and download files
Typical use: Transferring Web content from the developer’s PC to the Web server
Using Telnet, a user can remotely log on to a computer (connected to the user’s through a TCP/IP network, e.g. Internet) & have control over it like a local user, including control over running various programs
In contrast, FTP allows file operations only
Typical use: Configuring and testing of a remote Web server
www (The Web )
In 1991, the World Wide Web was developed by Tim Berners-Lee as a way for people to share information.
The hyper-text format available through his Web made the internet much easier to use because all documents could be seen easily on screen without downloading.
The first browser software—Mosaic—was introduced by Marc Andreesen in 1993, and it enabled more fluid use of images and graphics online and opened up a new world for internet users.
A user may access any item on the Web through a URL, e.g.
Before, going any further, I like to tell about URL
A URL (or uniform resource locator) is the unique address of any Web page on the World Wide Web. Here’s an example:
Protocol Identifier Server Address Directory & File Name
So, how do you get on to the World Wide Web?
A web browser is software that provides access to the World Wide Web. Internet Explorer , Netscape Navigator , and Firefox are some popular browsers .
DIFFERENT TYPES OF BROWSERS
Internet Explorer ,
Internet Explorer for Mac
Off By One
How does the Web work?
User launches the browser on his/her computer User’s Computer Browser
User types in the URL into the browser User’s Computer
The browser breaks down the URL User’s Computer http://www.vu.edu.pk/cs/index.html http Protocol Identifier www.vu.edu.pk Server’s Name cs/index.html Directory & File Name
Browser sends server’s name to the DNS server User’s Computer DNS Server Domain Name IP Address
Browser establishes a connection with the server User’s Computer Web Server Internet
Browser sends a ‘GET’ request for cs/index.html User’s Computer Web Server
Server sends the requested file to the browser User’s Computer Web Server
Browser displays index.html User’s Computer X
Inexpensive , and quite quick , but not instant !
The most popular service on the Internet, even more than surfing, but soon to be overtaken by instant messaging
Billions are sent every day
How does an eMail system work?
But first, the components:
Programs used for writing, sending, receiving , and displaying eMail messages
A protocol used to send and receive eMail messages over a TCP/IP network
POP3: Post Office Protocol
A protocol used for receiving eMail messages
A POP3 server maintains text files ( one file per user account ) containing all messages received by a user
eMail client interacts with the POP3 server for discovering and downloading new eMail messages
The message is prepared using the eMail client Sender’s Computer eMail Client
The eMail client sends it to the SMTP server Sender’s Computer SMTP Server
If the receiver is local, it goes to the POP3 server Sender’s Computer SMTP Server POP3 Server
The receiver picks it at his/her convenience Sender’s Computer POP3 Server SMTP Server Receiver's Computer
Otherwise, it is sent to receiver's SMTP server Sender’s Computer SMTP Server SMTP Server Internet
Which forwards it to the local POP3 server Sender’s Computer SMTP Server POP3 Server SMTP Server
The receiver picks it at his/her convenience Sender’s Computer SMTP Server POP3 Server SMTP Server Receiver's Computer
The Trouble with eMail
Slow response times
No way of knowing if the person we are sending eMail to is there to read it
The process of having a conversation through eMail by exchanging several short messages is too cumbersome
Instant messaging (IM) solves these problems
The IM services available on the Internet (e.g. ICQ, AIM, MSN Messenger, Yahoo! Messenger) allow us to maintain a list of people (contacts) that we interact with regularly
We can send an instant messages to any of the contacts in our list as long as that contact is online
Using Instant Messaging (1)
Whenever a contact in our list comes online , the IM client informs us through an alert message and by playing a sound
To send an instant message to a contact, just click on the contact in the IM client, and start typing the message
Using Instant Messaging (2)
The selected contact will receive that message almost immediately after you press ‘ Enter’
When the contact’s IM client receives the message , it alerts the contact with a blinking message and by playing a sound
Using Instant Messaging (3)
That contact then can type a response to the received message, and send it instantly
Several such conversations can be carried out simultaneously , each occupying a separate IM windows
How instant messaging works?
User launches the IM client My Computer IM Client Internet
IM client finds the IM server & logs in My Computer IM Server
It sends communication info (IP address, etc) to the IM server My Computer IM Server Temporary File
IM server finds user’s contacts & sends him/her the communication info for the ones online My Computer IM Server
IM server also tells the contacts that the user is online; sends his/her communication info to them My Computer IM Server Contact’s Computer
Now the user’s & the contact’s IM clients are ready to communicate directly (P2P) My Computer IM Server Contact’s Computer The IM server doesn’t play any part in this P2P communication
As new contact’s come online, IM server informs them about the user being online & vice versa My Computer IM Server Contact A’s Computer Contact B’s Computer
Multiple, simultaneous conversations are possible My Computer IM Server Contact A’s Computer Contact B’s Computer
When the user logs-off, his/her IM client informs the IM server My Computer IM Server Contact A’s Computer Contact B’s Computer
IM server erases the temporary file and informs the user’s contact’s about his/her ‘offline’ status My Computer IM Server Contact A’s Computer Contact B’s Computer
Once the IM server provides the communication info to the user and his/her contact’s IM client, the two are able to communicate with each other without the IM server’s assistance
This server-less connection is termed as a P2P connection
VoIP: Voice over IP
Voice delivered from one device to another using the Internet Protocol
Voice is first converted into a digital form , is broken down into packets, and then transmitted over a TCP/IP network (e.g. Internet)
Much cheaper than traditional phone service
Disadvantage Noticeably poor quality of voice as compared with land-line phone service, but not much worse than cell phone service
E commerce E commerce or electronic commerce is very important services provided by internet through which financial transitions are carried out over the internet, it is modern way to carry out business on international bases. When business is conducted with the help of computer network. This activity is usually termed as e commerce or e trade. Through e commerce, goods can be purchased and sold from any where in the world. Credit cards are used for payment. It is estimated that the size of e commerce is growing at a rate of 25% to 30% per month in the world. The e commerce can only be conducted on the computer network. Therefore computer network has become the need of every nation including Pakistan. The example of e commerce are; online shopping, online advertising, online banking etc.
Video Conferencing Equipment
Top 10 Uses
News and Weather
Job (Search & Work)
Advantages and Disadvantages of the Internet
Theft of Personal information
Did you know?
The Internet Service was started by the US military in 1969 with four computers. It grew and in the following 10 years it connected 200 computers in the military and educational establishments. By 1996, there were more than 50 million users connected to 4 million computers. The Internet service is available in about 200 countries.