Internet, the Information super highway. Nowadays, we are depending up on internet for each and everything. Whether you want to find the latest financial news, browse through library catalogs, exchange information with colleagues, or join in a lively political debate, the Internet is the tool that will take you beyond telephones, faxes, and isolated computers to a burgeoning networked information frontier. Internet populations is growing exponentially.
Just rewind a little bit. It all started with a Computer Network; 2 interconnected computers. Computer Network is the core of digital communication. But what is network? How does it work? Lets find out.
What is a Network?
Simply, a computer network is a set of computers connected together for the purpose of sharing resources and information.
Using network people can communicate with each other across the world at very low cost using services like chat and email. It can be used to transfer files and information between devices at a very high speed.
A single software can be installed on the server and all the clients in the network can use it instead of installing it on every individual PCs, reducing the cost of software. Devices like printers, scanners and other hardwares can be shared easily.
From Little Drops To the Mighty Ocean
The Internet is the best example of a public WAN.
WAN connects different MANs together and form a Wider Network. They are connected to each other by means of satellite or transoceanic cables.
Hello.. Who is it?
An IP address is similar to your phone number. Your phone number is a unique set of numbers that identifies your phone so that other people can call you. Similarly, an IP address is a unique set of numbers that identifies your computer so that it can send and receive data with other computers.
It is a numerical value combining 4, 8 bit binary digits or octets separated by dots that looks some what like this.
For our convenience we convert binary to decimal
0 . 0 . 0 . 0 (00000000.00000000.00000000.00000000)
255.255.255.255 (11111111 . 11111111 . 11111111 . 11111111)
Public IP address is an IP address that can be accessed over the Internet.
This IP address is unique throughout the internet.
This IP address is unique to a network. Private IP addresses are not directly exposed to the Internet.
That means we cannot access any device outside our LAN using its private IP address.
Classes Of IP Address
The network mask help us to identify which part of ip address is the network part and which part is the host part. In most cases, network mask is decided by the class of the IP address
For Example consider the IP
10.9.0.25 (Dotted Decimal )
00001010.00001001.00000000.00011001 (Dotted Binary)
In a network mask, all the bits in the network part will be 1 and host part will be 0.
Since it is a class A IP address, first octets will be 1s. So Subnet mask will be
So How Does It Work?
If we want internet connection in our home, we contact an ISP. ISP or Internet Service Provider is an Organization that provides us access to the internet. For example Asianet , BSNL etc. ISP gives us an IP address which can be used for accessing the internet. Modem simply demodulates the incoming packets and modulates the outgoing packets. If we have a single PC, we can directly connect modem to that PC.
If we have multiple devices within our home we will have to use a router.
Router is a device which is used for connecting two networks together. Router creates a private network and assign private IP to all our devices. Here, our router get the public IP address from the ISP, and each of the devices connected to our router get a private IP. These private IPs will be mapped to the public IP using technique called NAT.