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.

     As OSI has a very sound logical base as far as layering is concerned, today any protocol developed in communication, is compared with OSI for a better understanding, like CCS7, TCP-IP, and many more. Just have a look at the layers…..I will explain them in my next blog.

                         

    Layering? :-

Having said that, let us see what is layering and why this is being done. Layering is done simplify the understandability and implementation of the whole complex job of communication between computer networks. The idea is to clearly demarcate the types of jobs need to be done to achieve the ultimate goal of transferring the data among two or more Computers. A change in one layer is not going to affect the other layers. This is just like running an organization or a college, where the jobs of the Dean and the security guard are different .One’s way of doing the job is not going to affect that of the other, but for the ultimate job of running the organization, both are needed.

   So, when a software geek is developing applications in Apple IOS, Anroid or Java he is not going to worry about how these will reach to others at the very physical level. The data may take any path like Fibres, plain Cu wires or radio frequencies. The engineers working in these physical paths need not to worry about the applications being developed.  Any question?..Just drop a commentThat’s it!