OSI Model

[zillah2004]

1- Dose OSI Model has applicability to the “real world”?

[Kevin Dorrell]

Yes, quite definitely, especially the bottom four layers. These are essential to networking, and you need to understand them to understand what is going on in the "real world".

As for the upper three layers, in the IETF model, these are lumped together as "Application". But they are still applicable to understanding what is going within that "Application".

Kevin Dorrell

Luxembourg

[zillah2004]

Thanks Kevin.

You said "I need to understand them to understand what is going on"

Suppose I do not want to know what is going on ?

The reason why I am asking this question; because I am comparing with programing language, if you do not know the programing language you can not write the code, then from this view, I have to know and undertsnad the language of programing, but do I need to know for instance that switch in layer 2 or hub in layer 1, or ARP in layer 3----etc?

[Kevin Dorrell]

"Suppose I do not want to know what is going on?"

I guess you do want to know what is going on, because otherwise you wouldn't be here on this forum.

Your comparison with knowing the programming language is not quite what the OSI model it is about. In programming terms, the OSI model is more like do you understand the concept of a procedure call, of an interrupt routine, of a process switch, of a semaphore, etc. Do you know the difference between an exception handler and a subroutine?

Kevin Dorrell

Luxembourg

[zillah2004]

Thanks kelvin

Now could you please tell when we use TCP/IP is belong to OSI model(7layer) or TCP/IP model (4 layer)?

[Kevin Dorrell]

TCP is layer 4. IP is layer 3. Both models.