Information about Internet

Internet Connection - Information about Internet - DNS - DSL - ISDN - ISP

Connection to the Internet

Normally, dial-up access is used to connect to the Internet at home or office. Following things are required to establish connection to Internet:

* Computer – Any computer can be used for connection to Internet.
* Modem – Modem is an electronic device that is used to transfer data over Internet. It links the computer with the Internet using telephone line.
* Dialup Software – Dialup software is used to establish a connection between a personal computer and a server of an ISP.
* ISP Connection – ISP stands for Internet Service Provider. I t provides the link between the computer and the Internet. A person has to get an account of an ISP for establishing a connection to Internet.
* Web Browser – Finally, an Internet browser is required. Browser is software that is used to view web pages. Microsoft Internet Explorer and Netscape Communicator are popular web browsers.

More high-speed connections are also available to connect to the Internet such as DSL, ISDN and cable television Internet services. DSL stands for digital subscriber line and ISDN stands for Integrated Services Digital Network. These technologies provide high-speed connections through cable television network.

These technologies are always connected to the Internet when the computer is running. The users do not have to dial a connection to connect to the Internet, which is necessary in case of dial-up access.

Addressing Scheme

Internet addresses are used to access different computers on the Internet. Each computer on the Internet has unique address. This address is sued to establish a connection with that computer. There are two types of addressing schemes on the Internet.

IP Addressing

IP address is a unique number that refers to a computer connected to the Internet. IP stands for Internet Protocol. This address is a 32-bit number. It consists of four numbers separated by period. Each number is between 0 and 255. These numbers are known as octets.

An example of IP address is 127.80.144.30. Normally, first number indicates a network and that last number indicates a specific computer.

A server on the Internet has a static IP address. It does not change very often. When a computer connects to the Internet, It also gets in IP address by the ISP. This IP address is used only during the session and is not static.

DNS Addressing

IP address is difficult to remember for the users. An alternative to IP address is known as domain name. a domain name consists of text instead of number. It is easier to remember a domain name than IP address. A domain name is associated with one or more IP addresses.

Each domain name has a top-level domain that indicates the type of organization associated with domain name. The domain names outside United States also include the country code. The country code of Pakistan is pk e.g. www.hec.gov.pk

Internet Corporation for Assigned Name and Numbers (ICANN) is a group that assigns and controls the top-level domains.

A method used to store domain names and corresponding IP addresses is called domain name system (DNS). When the user specifies a domain name, DNS server converts it into its corresponding IP address.