How Internet works?

The awesomeness of the Internet can't be captured by any single lecture or a video. There are a lot of hardwares, softwares, protocols, policies, devices, whole lot of human thinking that makes it possible to connect to any part of the world in just  fractions of a second.

Animation :TCP vis-a-vas UDP

TCP is a heavyweight, connection oriented Transport layer protocol.When a file or message send it will get delivered unless connections fails. If connection lost, the server will request the lost part. There is no corruption while there is transfer of message. The message will be in ordered way.Used for bigger segments. Examples of applications using TCP are World Wide Web (Apache TCP port 80), e-mail (SMTP TCP port 25 Postfix MTA), File Transfer Protocol (FTP port 21) and Secure Shell (Open SSH port 22) etc.
UDP is lightweight, connectionless Transport layer protocol.Once we send a data or message, we don't know if it'll get there, it could get lost on the way. There may be corruption on the way to the destination.The received message may or may not in ordered way.Used for smaller segments.Examples of applications using UDP are Domain Name System (DNS UDP port 53), streaming media applications such as IPTV or movies, Voice over IP (VoIP), Trivial File Transfer Protocol (TFTP) and online multiplayer games etc.
   Understand the two protocols through the animations below.

Animation:The journey of an E-Mail...

Technology has given us an instant means of sending letters i.e. E-mail. Whereas E-mail is fast but the hand written traditional letters carry much-much affection. I still remember those days when I was in school, watching my parents waiting for a letter from our loved ones. While Email gives you instant gratification, still the real love is carried by the traditional hand written letters with the touch and the fragrance of the real loved ones.Both the ways are great ways of communication.The post offices facilitates the journey of our traditional letters.Have we ever wondered how an E-mail travels through Internet. The protocols that facilitates this are the SMTP(Simple mail transfer protocol) and the POP(Post Office Protocol).

Increase Internet speed by 20%...

Microsoft reserves 20% of the bandwidth for their own purposes like Windows Updates, questioning the PC etc. That 20 % can be retrieved back for your use !

Understand ARP through animation

All interfaces in the network are identified by an IP address. The IP header encapsulated at the Network layer carries the ultimate source and destination IP addresses. However, for actual transmission, these IP datagrams are encapsulated in Data Link layer frames. The header in this layer carries the hardware addresses of the immediate source and destination.

TCP-IP and the DATA Flow....

In this post, I am not going to discuss in details about how a packet flow through network using TCP-IP layered protocol. My aim here is to share what I understand as to how TCP-IP protocol stack modifies a data and helps it to reach final destination. Please do comment and share, if my knowledge needs modification anywhere. Read on….. 

The Cloud Storage Options..G-Drive and others

The much awaited cloud based storage of the Google-team, the Google-drive has been launched on 24th April,2012, for which many were eagerly waiting.

The service is offering 5GB of on-line storage space for documents,videos,photos,PDFs and other files. The great thing is that the Google Docs utility is in-built  with it. With Google Docs you can maintain on-line word docs, spreadsheets, Presentations, edit them from anywhere or download them in the format in which you want. With Google-drive , one can share any file with anybody and work with others in real time. Anybody can make changes in the shared file and work upon a single project.

Make your Windows PC faster......

We all are sometimes tired of the sluggish performance of our Windows PC. Our own PC becomes a a necessary evil.Do not worry, there are lot of ways to tune your PC,for delivering best performance.
 Here I present some ways to make PC start and run faster.

Hubs, Switches & Routers..the basic differences

In Networking, Hubs ,switches and routers are the very basic and important devices.I have tabulated the basic differences among them, without going into much details.

“How to type the language you speak”

Can you type in English? If your answer is yes, you can type in the script of Hindi (Devanagari), Bengali or any Indian language. I will explain in easy steps and show certain snapshots of my computer screen for better and clear understanding.

OSI & TCP-IP, Part-2

The OSI &  the TCPIP
    First of all we must understand that internet works with packet switching technology, where the information is broken down into packets. Each packet will then trace any path to the destination. Along the path from the source to the destination, it will come across many nodes. The nodes may be any network device but it must understand the language of the layered structured model (TCPIP in the case of internet).
    At every node, each layer of the protocol suite will do some exercise on the packet, as per the requirement. I mean to say that, the layers will impose some rules on the packet, to make it actually deliverable over the network.
  As OSI is the most logical standard, it will be discussed first and then it will be seen how 4 layers TCP-IP fits into this 7 layers OSI model. OSI or TCPIP is not a single protocol but a collection of many protocols at different layers. They have been developed over years and still improving as per the need of the modern networking community.
We should be kept informed that all the developments in internet have been contributed by users only and the good thing is that anybody can do that!  ( thanks to IETF )
The OSI model has got 7-layers as depicted below. The counting is from the lowest layer. So Physical layer is 1st layer, Data-link is 2nd, Network is the 3rd and so-on. We shall try to understand one by one.

OSI & TCP-IP, Part-1

      I have already mentioned that TCP-IP is the protocol based on which Internet works. TCP-IP is not a single protocol, but a collection of many standard protocols, and therefore called TCP-IP protocol suite. The term TCP-IP was coined from the most important protocols in the suite the “Transmission Control Protocol” & the “Internet protocol”. It was developed (and still developing) and implemented in the late 1970’s. OSI or Open system Interconnection was proposed in 1978 by ISO (International Standard Organization, which is a 7-layered reference model. Now, let me try to explain the similarities and differences between the two, which can be summarized in following points:-

 1) TCP-IP was born first (in late1970’s) and then the OSI (in1978).

2) Both the protocols explain about how two computers or networks should communicate in a logical way.

 3) Both the protocol has got layered structure. OSI has 7 layers and TCP-IP has 4.

 4) Though OSI is a more logical way of carrying out the layering, TCP-IP is the accepted protocol for the working of Internet. Actually, the point is that when OSI was proposed in 1978, Internet was already working fine with TCP-IP, and it became baseless to disturb the already functional and useful application i.e. Internet.

The Internet & The TCP-IP

        I have been and will always be overwhelmed by the way this huge infrastructure called “Internet” works.  Formally the definition of Internet is “The network formed by the cooperative interconnection of a large number of computer networks”. Please mind the words “cooperative interconnection”, from which you can draw at least three inferences: