OSI Seven Layer Model

ally_uk

simple question

Is it really nessicary to learn the ins and outs of the OSI

I mean in a day to day network role does it has it's use's or is this just knowledge you have to impress people

I am pretty familar with the OSI but can't say I have used it yet

How can I make full use of it When using a network

Thanks

Ally

Webmaster

Well, 'ins and outs' goes a bit far for Network+, but a good understanding of the OSI model and how network technologies relate to it really is imperative if you want to go further with networking.

In my TechNotes I wrote:

The OSI (Open System Interconnection) model is developed by ISO in 1984 to provide a reference model for the complex aspects related to network communication. It divides the different functions and services provided by network technology in 7 layers. This facilitates modular engineering, simplifies teaching and learning network technologies, helps to isolate problems, and allows vendors to focus on just the layer(s) in which their hardware or software is implemented and enables them to create products that are compatible, standardized, and interoperable.[/i]

Another one that could have been listed in bold is 'design', but those the two bold ones above are probably the ones were the OSI model is of most use for you.

If you don't really understand the OSI model, you cannot fully understand what goes on in a network, or network device, it is that essential. That said, for the Network+ cert it's more important to know of the OSI model, its layers, the order of layers, and what devices/protocols/service operate on certain layers, then to fully comprehend it. I know the OSI model can be pretty vague at first, seemingly useless theory, but keep in mind it's 'just' a model that makes it easier to understand (offers a modular approach) and discuss the many things that go on in networks. You probably apply the layered approach of the OSI model more often than you realize. I.e. checking a cable/ connection to exlcude physical layer problems.

Plantwiz

I agree with Johan, and while I cannot improve on what he said, I'll add that in 'real' life not all the layers of the OSI are used in every situation....hence the 'theory' comment.

Maybe work with someone who does have a bit more familiarity with the OSI and work on identifing the layers in everyday situations to help visualize it for you?

HTH

kenny504

The OSI Model is a logical model. We work with it everyday, perhaps the main benefit of the OSI model is it makes problem isolation and solving alot more easier through its layered approach. Directly you might not be able to pin-point what it is that the OSI model can do for you within a network but indirectly it makes understanding the communication process more simple. Hence. once you have an understanding of that through knowledge of the OSI model you can apply that understanding to network devices and problems that can occur with them.


A good way to look at the OSI model is to think of it like high school algerbra..we always wondered when and how can i apply this in the real world..Later on in life you realize that algerbra actually helped you with alot of stuff,..not so much directly but through its actual application, stuff like college geometry and many different cipher algorithms. Algebra works on masked logic. So does the OSI model. The logic may not be explicit but it will always be applied, even when you dont see it.