Working of Internet :-
Before you can explore the internet, you need to have access to a computer that is a part of the network. If you have a telephone you cannot make the call unit unless you say to have the line connected by the phone company, so you can hear a dial tone. In the same way, you can't dial internets services until your modem can connect with a computer that is a part of the internet. You will also require web browsers software like Microsoft internet explorer or Netscape navigator etc. Web pages will provide you lots of features of the internet communication like submission of an application form or searching a research topic.
Connection Types :-
In general you can make three types of connections:
Direct Internet Link
Dial-Up Access Through internet service provider
Indirect Access through another service
Direct Internet Link :-
If you are connecting more than 20 people who require simultaneous and permanent internet connections, you need a listed line terminal server, router and other equipment. Integrated services digital network is basically used for communication of both data and voice. This is switched digital service that is used usually sold on a time and distance rate schedule just like phone calls. It has the following features:
1. Transmission and processing of digital data
2. Processing of various types of information data, voice, video etc.
3. Electronic mail box.
4. Tele-Conferencing, Tele fax, video fax etc.
Dial up access through Internet Service Provider :-
This is the simple and cheapest type of connection to internet. Individuals and small business ca best access the internet using a dial-up connection. A dial-up connections simply means that when you want to access the internet, your modem dial is a host computer and you can go about your business; you are done, just hang up the modem to free the phone line. A dial-up access only need a computer and modem, a phone line, an account with a service provider, and approximate software.
Indirect access through Another Service :-
In this type of connection a local service provider has access to internet via leased line. This local service provider in turn provides internet service to users without any user account for the ISP. Cable-net is a very good example of this type of connection.
Types of Internet Account :-
Shell Account :-
You must knowing what an account is. But is meant by shell. Being more precise a shall is the program that translates and sends your command to your system’s core. This happen because the core doesn’t understand the command you give. Using dial-up access to GIAS (Gateway Internet Access Service) HOST the primary level of access for internet users-one can dial-up access to GIAS HOST computer set up by VSNL , at each of the nodes. By connecting to the host computer, the users would be able to use all internet services. In this mode, the users would be using a simple terminal emulation from their PCs and will not require any special software of their machines. The limitation of this access mode is that the access is primarily limited to text-based services.
PPA Account :-
PPA account is the internet account that uses PPP(Point to Point) communication protocol, the most kind popular kind of internet account. Point to Point protocol is used to create your connection over one’s along telephone modem to you ISP and the internet. Your computer will use communication ports, known as “COM” ports to access your modem.
Types of internet Access :-
Depending on how you establish your link with internet, your access may be limited. While direct internet connections can offer the free and faster access to the net, links through some providers or other service might offer less than full access. In general there are two types of access:
Full Access :- This type allows you to take advantage of all network features and commands. You can use e-mail , long into other computer systems, access their resources transfer files ,access USENET.
Limited Access :- This type only allows you to do a few things on the internet. Most often you can only use the e-mail facilities and possibly USENET. You cannot log into other computer systems, nor can you transfer files. USENET is a network that actually predates the internet. It is not similar to electronic bulletin-board systems, which are familiar to many computer users.
How Does the Internet Works :-
Internet is all about sharing resources. The major resource which to distant computers may share is information, which exists in computers in the form of files. Thus, the essence of the networking lies is moving files from one place to another. For the communication it requires :
1. The Destination Address
2. A methodology by which files can be received or sent.
For the moving files one place to another, there exists a set of rules, which governors sending and receiving of data on the internet. TCP stand for Transmission Control Protocol and IP stand for Internet Protocol. For sending a file to another distant computer:
1. TCP provides the data into little data packets.
2. Special information e.g. the packet position in the document, error correction etc.