What is Router? (What is the difference between a Router, a Switch, a Hub and a Bridge)

Router is probably the heart and soul of a computer network. It can be compared to that department of a Post Office which is responsible for classification of mail based on address. Router is pretty much like an intermediate post office. A router receives data from a node, a computer or many a times a neighboring router. It is then responsible for the following primary functions:

1. On receiving data it looks at the content which has information (source, destination, size, priority etc.) about the data. 
2. It looks up its own data base to find a the best route for the data 
3. It choses the appropriate output channel and sends data on it to the next "hop"

Hop is nothing but a jump to the next node. If someone tells you, "The maximum hop of this data is 7" it means that this data can travel across 7 nodes only after which it will cease to exist. 

This is a very primitive explanation of a router good enough for a beginner to get hold of the concept. I will deal with it in much details in the next few days. I am currently working on a technology called Optical Burst Switching and also on routers that can support this technology. As such routers is my love and would like to do justice to it :) 

Hope to have you engaged in this work! 

What is Layering in networks and what are the OSI layers?

When computer networks evolved, all players designed systems to their standards. These systems could not interact with other systems. This restricted the efficiency that can be truly achieved of a computer network. So the governing bodies like International Telecommunication Union along with the International Standards organization decided to come together and devise a "Standard" for the computer networks.  This standard was to ensure that no matter who and where the components were designed (and built), those would still be able to communicate with other components seamlessly.

In this process the OSI model was proposed. OSI stands for Open System Interconnection. The OSI model breaks up the entire network into 7 layers. The idea behind layering is to distribute functions at different layers such that no single layer is responsible for the entire communication process. However, at the same time the lower layers are oblivious of the layers above and the upper layers use the lower layers for services. Hmm... confusing? Dont worry it will be simple in the next few lines. 

What is the Internet?

Let's look at a network first. A network is a connection of 2 or more computers. Yes as simple as that yet complicated enough for universities and corporates to deploy brightest men of the nation to work on this aspect of technology!!!

Sorry for the lil digression but had to state the importance of a network. Anyhow so network is essentially two or more computers talking to each other. The Internet or the World Wide Web that often visit is a mega-mega-huge collection of such computers tied together. The information that we see online is stored in some remote memory location monitored and controlled by another computer. 

There are certain things that make computer networks a bit complicated than it seems. Here are some of the critical issues  that need a close attention while designing a network: 

1. Number of computers  (also called as nodes)
2. Medium of communication: wired (optical/electrical) or wireless
3. Protocols or language of communication
4. Physical distance between nodes
5. Number of users on the network

there are many other technical issues which I will cover over the next few blogs.

What is a Computer?

Hmm some of the readers might think this a very trivial question. However it is important to note that this is the building block of all networks including the World Wide Web that we crawl on everyday. So what is this thing? 

A computer, very simply, is a device that computes or calculates. It is a CALCULATOR! However a notch better. A computer consists of 3 things: Input Device(s), a Processing Unit and a Display (output) Device(s). the input devices are the keyboards and the mice. With these one can type in data (numbers, alphabets, special characters etc). This information is then processed in the processing unit which takes data from the input devices and processes it. Once that is done, the processed information is displayed on the output device or the display device (monitor) for the user to verify. Oh by the way all of this is done within few seconds or even less than that depending on the processing unit. 

That is a computer. Got it????    

Why Take Tech Talk?

One fine evening, in Houston, while i came back from school i realized that a lot of my time was spent on Facebook. It's the 'in' thing today but what struck me was not the amount of time spent on it... but the amount of information gathered in those short visits on my wall. I asked my fellow driver of a recent roadtrip , "What was the best part of the road trip according to you?". He said, "The bright Full Moon showing up out of nowhere behind the hill and Grand canyon". I agreed but with an addition. I was away from the deluge of information. No internet, no phones... just the road and mother nature!!

That brought me to another question... What is the most important thing of our lives ? I guess in the present day world, besides the basic needs (water, food, air etc.) it is information..! Would you disagree? I mean look at the world around us. We are surrounded by a plethora of smart devices which not only are efficient but make us efficient. 

I then thought how about just making a note of my perspective of the technology that drives this information deep into our lives. So here is to the blessing called Internet, Computers, and Networks! Hope you all enjoy it and leave feedback for me to develop while you benefit from it. 

cheers

Vikram