The Internet is a worldwide network of networks. It is a conglomeration of smaller networks and other connected machines spanning the entire globe. It consists of over 30,000 networks in 71 countries. Around the world, each country has at least one backbone network that operates at a very high speed and carries the bulk of the traffic. Other smaller networks are connect to the backbone.
The Internet has no central authority-networks on the Internet simply agree to corporate with each other. Individual computers on these networks can share files and transmit information. Various networks connected to the Internet format messages with Internet Protocol (IP). IP is often used in conjunction with TCP (Transmission Control Protocol). The combination of TCP/IP has made the Internet robust and flexible.
Purpose of Internet
The Internet has revolutionized the communication methods around the world. Sitting at a workstation or PC, one can get any kind of information one wants. The latest technological advances have enables it to be used as a business tool as well, with the result that companies are today spending considerable amount of money on Internet research. The amalgamation of computer and communication technologies has resulted in the integration of data, sound and video on the Internet, which in turn has made it a powerful tool for re-engineering business processes the world over.
One can use the Internet for the following purpose:
(a) To exchange electronic mail with friends all over the globe for a small price.
(b) To participate in group discussions on topics of interest, through public news groups.
(c) To find educational tools. Universities around the world, book stores, and libraries are sharing on-line information.
(d) To shop-commercial electronic store fronts are growing in number in the USA and Europe. One can order different products over the Internet.
(e) In the case of business one can get technical support for products one is using. One can publish information such as technical or marketing literature.
(f) Because the Internet is electronic, one can make changes to reflect late breaking news that would be impossible for printed publications. Change becomes easier, updates are simpler and information is instant.
(g) The Internet has become the first global venue for publishing information. This network has enough users now and it is benefiting from the positive feedback loop: the more users it gets, the more content it gets; and the more content it gets, the more users it gets.
(h) Internet’s main asset is freedom. An alternative to controlling its freedom is to train and educate the user.
Internet Connection Options
There are several ways to connect to the Internet. The more expensive services provide more feature, more flexibility, and greater data transfer capacity. Large companies would choose dedicated Internet access or LAN dial-up. Smaller organizations may be happy with PC dial-up access and terminal emulation, which provides e-mail and other services through a service provider’s computer.
PC Dial-up and Terminal Emulation This is the simplest and cheapest type of connection to make. All you need is a computer with a modem (attached to a phone line) and any of the popular telecommunications packages. The individual user dials-in to an Internet provider. Each user has an account on the provider’s Internet Services host computer to the Internet.
When you use PC dial-up (also called a terminal account), your computer runs a terminal emulation program to communicate with service provider’s host computer, and you ask the host computer to go out on the internet to do what you need to be done. Most host providers will send and receive e-mail, transfer files from a remote Internet computer to the host which you can then download to your local computer, and provide access to USENET (the topical bulletin boards/newspaper/discussion groups on the Internet).
Many Internet access providers also allow dial-up users to interactively roam the Internet in real time, logging on to remote hosts with TELNET, searching indexed databases with WAIS, and locating esoteric information with Gopher.
The equipment and software for PC dial-up is essentially the same-whether the user is dialing from a stand alone computer at home, or from a networked computer equipped with a local modem, or from a networked computer equipped with a local modem, or from a networked computer using a communications server and a shared pool of network modems.
The computer uses terminal emulation software, not TCP/IP to talk to the Internet host computer. The Internet host computer uses TCP/IP to talk to the Internet. Ordinary modems and telephones lines provide adequate throughout for PC dial-up access, though fast modems make the experience more pleasant. If you are trying to connect a NetWare LAN to the Internet, you have a number of options. Some people use a UNIX computer to connect the LAN to the Internet. The advantage is that UNIX will interface easily with internet. Other people prefer to stick to a NetWare solution. Because NetWare 4.0 id transport independent, it will send data from a workstation to a file server using either Internet. An an alternative to a commercial X.25 connection between two distant cities, the internet is unbeatable. It is not secure, but it is cheaper per bit than any of the alternatives and quite reliable.
Internet Service Providers After you decide what kind of Internet connection you need, look for a service provider. A wide variety of providers support a wide variety of Internet connection services. Here are some hints.
If you want to connect an individual PC to the Internet, you can choose a national provider. If you want to connect several users geographically scattered sites, contact one of the major national and regional Internet providers. To get a dedicated line into the Internet, contact one of the leased line; the more traffic it can carry the more expensive it will be. A final word of caution before connecting your network to the Internet. A large number of people have made it their pastime to break into computer networks. There are many stories of companies that have plugged their networks in to the Internet, not realizing that at that point, anyone from Russia to the Fiji Islands could look at their files.
Whichever system you choose, make sure that it is implemented. It is easy to believe that you are invisible, but that is not true. Tools are now available to automatically scan for new IP addresses as well as weak points in your defences. Set your security properly before you connect for the first time.
How India is Connected to the Internet? Videsh Sanchar Nigam Ltd, India’s international telecom carrier, has also provided a backbone network in India known as VSNL’s Gateway Internet Access Services node at Bombay to Internet node in the USA via satellite and to Internet access nodes at Calcutta, New Delhi and Chennai. In addition more nodes in several other cities are likely to be commisioned in the near future. These nodes will be connected to the main Internet access node at Mumbai through DoT provided intercity links. Internet access node at Mumbai is also connected to VSNL’s gateway packet switched service (GPSS). As DoT remote area business message network (RABMN), domestic packet switched network, I-Net and high-speed V-SAT network (HVNET) are connected to GPSS. Subscribers of these networks would also have easy access to full range of Internet service. Subscribers form over 4300 STD cities of India would also be able to avail advantage of Internet services by subscribing to ‘099’ access of 1-Net in addition to subscribing to GIAS.
VSNL’s Options for accessing Gateway VSNL has planned the following options for accessing gateway Internet access service (GIAS).
Shell account Using dial-up access to GIAS 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 no require any special software on their machine. The limitation of this access mode is that the access is primarily limited to text-based services.
TCP/IP account VSNL,– as the second level of access, provides a direct TCP/IP account. The subscribers can use transmission control protocol / Internet Protocol (TCP/IP) software to connect on a dial-up or leased basis to the GIAS system and access all on-line services on the internet. In this mode of access, the users will be required to use software to use software for e-mail, file transfer, remote log-in, Mosaic, World Wide Web, etc.
Packet switched access VSNL,- as the third level of access, provides access via packet switched network, i.e. GPSS, I-Net, RABMN and HVNET. Subscribers of these networks would be able to avail the full range of internet services using shell account or TCP/IP account. Shell account subscribers using terminal dial-up can access GIAS HOST computer and avail all Internet services, i.e. E-mail, file transfer, remote log-in, etc. primarily limited to text-based services. TCP/IP account subscribers would be required to have router capable of routing TCP/IP over X.25 and connected to the VSNL GIAS router. in this type of access, users would require to have software needed for e-mail, file transfer, remote log-in, Mosaic, World Wide web, etc
Internet Security– It would be a grave mistake to assume that the internet is a safe place, and that there is no reason for one to protect one’s password. Unfortunately, there are a lot of people who would love to break into other/ accounts and user them as a base for operations.
Inet- Inet is the X.25 based public data network which offers services like connectivity to Internet and e-mail providers. Inet is india’s X.25 based packet switched public data networks. It provides high-speed connectivity between computers/terminals. Inet is based on Packet switching technology incorporating error detection and correction techniques. Packet swtiching enables error free transmission and interconnection of computer/terminals at different speeds and protocols. Inet is now opeational in 8 cities, namely Ahemdabad, Bangalore, Mumbai, Calcutta, New Delhi, Hyderabad, Chennai and Pune. inet offers the X.25, X.32, X.28 dial-up types of connections. Typical applications of Inet are as follows:
1. Internet connectivity
2. Electronic mail server
3. Corporate communications
4. Database services
5. Remote Job Applications
6. Travel reservations
7. Electronic Fund Transfer
8. Credit Card Verification
INTRANET
Intranet are the two or more independent networks that are connected and yet maintain independent identities. When you build a LAN, MAN or WAN-that is, a private network-using Internet standards, you have created an Internet, or intranet. Intranets offer a great deal of promise for simplifying the networking of different manufacturer’s components; used properly, intranets can reduce costs and simplify life for your end-users as well. Maintaining private networks without using Internet is very expensive because you need to have communication links such as satellite link for wide area networks. But in the case of Internet, these are all available and you pay for the cost of the local telephone call charges for making long distances connections. However security is a major problem in Intranet world. Hackers may have an access to your system and take away the information or data from the servers.
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