Internet Concepts

Listening the word Internet Concepts the first Question stuck to the mind is....

What is Internet..?

• Internet is a global network of interconnected computers over world wide web.
• It is a global web of computers that allows individuals to communicate with each other.
• Internet consists of two types of computers:
• Server
  Server is a computer or program that fulfils the request of another computer or program.
• Client
  Client is a computer or program that requests a service of another computer or program.

Applications of Internet

• Communicate with other people
• Sharing information or resources
• Connect to other computer systems

Types of Network

• MILNET    -    Military Network
• DARPA      -    Defense Advanced Research Network
• BITNET     -    Because it’s Time Network
• USENET    -    User Network
• NSFNET    -    National Science Foundation Network.
• ARPANET -   Advanced Research Projects Agency/Administration Network

History of Internet

• In 1969, the Department of Defense (DOD) of the United States (US) started a network using four computers at four separate universities throughout the United States enabling users to share resources and information, which was known as ARPAnet(Advanced Research Projects Administration Network).
• In 1972, there were 37 computers connected to ARPANET. In that year, ARPA’s name was changed to DARPA (Defense ARPA).
• In order to manage the size and complexity of the network were broken into two parts:
• MILNET-for managing Military sites
• ARPANET –for managing non-military sites(Network for research and educative purpose)
• In 1970’s other networks like BITNET and USENET also come into being.
• In 1980’s NSFNET was created. NSFNET allowed universities and research agencies to link up with its super computer.

 # How Internet works...?

• Internet is a global network of computers, each computer connected to the internet must have a unique address. That address is known as IP address.
• Internet includes thousands of host computers(servers) which provides data and services as requested by client system.

1. Message starts
2. Message is divided into small chunks known as packets
3. Each packets are assigned a port number.
4. Each packets receives its destination address.
5. Data conversion from analog to digital and vice versa.
6. The ISPs router examines the destination address in each packet and determines where to send it.

 ISP(Internet Service Provider)

• When you connect your computer to the internet, you are connecting to a special type of server which is provided & operated by your ISP.
• The job of this ISP is to provide the link between your browser & the rest of the internet.
• The single ISP server handles the internet connections of many individual browsers.
• The main component of providing access to the Internet consists of:
  International connectivity, which allows you to connect to the amorphous(unstructured) Internet.
  Domestic connectivity, which allows you to connect to the domestic gateway.
• There are three ways an ISP can connect to the Internet:
• VSNL(Videsh Sanchar Nigam Limited)/DOT(Department of Telecommunications)
• STPI(Software Technology Park India)Private Operators
• VSNL-VSNL is india’s leading provider of international telecommunications and Internet services.
• DOT-DOT is responsible for issuing security clearances.
• STPI- STPI is a semi government organization that has authorized to sell international gateway services to companies involved in developing software
• Private Operators- Private operators are a private independent companies competing directly with the multi-system operators