Fundamental Concepts of Internet
This post is a continuation of our previous Information Systems class, where we were introduced to the fundamental terms of the Internet Technology. Having worked for almost 5 years in Cisco, I felt obliged to share my knowledge with all of you.
In the beginning I would like to point out that all the technical concepts of Internet communication have been inspired from the real world. I mean that the different protocols that are currently being used by computers to communicate with each other are very similar to the ones we use in our daily life.
The fundamental unit of information in computer networking is known as Packet. Each Packet holds all the data that is being communicated between computers in the internet. Now, to send this packet from one computer to another we require addresses. Compare this situation to the one where we send letters from one address to the other. The terminology used in the Internet technology is known as IP Addresses. Each computer connected to the internet should have a unique IP Address associated with it. When packets are being transmitted from one computer to another, they are stamped with both the Source IP Address and Destination IP Address. Both the source and destination addresses are mandatory for the communication. When the packet reaches the destination, the destination computer processes the packet and then it replies back to the source. In order to reply to the source, the IP addresses are swapped, i.e. the source IP address becomes the destination and vice-versa.
An IP address (according to IP version 4) is of the format x.x.x.x, where each x is a number between 0-255. So there can be a total of 2^32 unique IP addresses, which is like a huge number of addresses. But the amazing fact is that we are already short of addresses by using this scheme of addressing!! The internet has grown so massively that even 4,294,967,296 addresses fell short. So, we are now gradually migrating towards a new format of IP addressing scheme called as IPV6 (version 6). For further readings on the IP Addresses you can take a look at the following links:
There are millions and millions of computer in the internet. Imagine the number of packets that are flowing in the internet constantly! It’s humongous. So there are lots and lots of intelligent devices working in the background and making sure that the traffic flow is smooth, fast and reliable. Some of the most fundamental backbone devices of the internet are”
To understand the functionality of these devices clearly you have to understand the concept of Network Layers, which I will cover in one of the future posts. As of now you can think of these devices as traffic controllers, which make sure all you packets reach their destination by taking the shortest possible path and time. They also do error correction control and make the system more reliable.
This is one of those devices which control the security of your network. You can define your policies and based on those policies, the firewall inspects every incoming packet. If the policy criteria match with the packet details, the specified action will be taken on that packet. The action can be one of Accept or Drop.
There are plenty of other devices like the Server Load Balancers, VMWare servers, Global Site Selectors, Security threat detector and protector etc…
I am going to cover the functionality of all the devices mentioned above in my future posts. This is just the beginning…
