Going to talk about this also model and all it stands for Open Systems Interconnection, and this was
proposed.
Why are you so I just sort of stands for international standards and organization.
So the main aim is to establish communication between the different systems in the olden days, if you
buy a CPU or any computer peripherals from one company, supposedly, and you need to IBM in order to
say there is no there are be OK, if you say you want to buy a computer from IBM, then you need to
buy the monitor and speakers and everything from the IBM because there is no compatibility between different
devices.
And that's why even in the network, there is no compatibility between not computers.
That's why these are so this whole proposal, this model and this is only theoretical model, but this
is the heart of the cookie.
This model is divided into seven years and each there is like a stack of seven layers and each that
performs its own task.
So these players perform some task and each had its own header to the data, thus enabling encapsulation.
So what this means is that their process, its data could go next year and that next year does not know
about this data.
It simply adds its own header and then send to the next player and so on test.
It doesn't know what data is in there from the previous year.
So let's see are the seven layers.
So as you can see from top to bottom, these are seven layers.
But we will consider from bottom to top that this first one is fiscal data that are there and network
layer transport, recession representation and opposition position there.
So you need to consider from bottom to top this layer, one, two, three, four, five, six, seven.
So since you are running, this is a model.
I have mentioned the names, but in general, when you are going for interviews, you do not mention
that because the only thing that you recently learned this, that names, that's what you are mentioning,
that they always mentioned that layer number.
So one, two, three.
So if this is if you want to mention transfer 104.
So in that case, the circumstances that you have some better understanding of these layers, but mention
that layer names, um, near the haters.
Are any interviews OK, coming to the future?
This is one fiscal year.
This fiscal year consist of the wires, cables and the network devices.
And Hub's comes into this fiscal year and this is great.
These are with the transmission of bits.
So in ways that I will be sent as if it's zeros and ones.
And coming to this referred to is the data.
So at this where the switches operate at this rate, thus we just transfer the data from one computer
to another computer based on a Mac address.
And these switches calls the macro stable of these computers and then transfer the data from one country
to another computer based on the megadoses, I mean the megadoses.
So the main important thing you need to know about this layer to these switches perform at this rate
and the coming together to this network layer.
And at this layer, rotas perform.
But in general, Rodust perform all the task up to these three layers.
But generally it is mentioned that routers operate at this rate and routers are responsible for assigning
the IP address on computer and doing some other network address, translation and portraitist translations
to maintain the IP addresses to not to exceed the IP address remit.
So we talking with this network and Bridgid in a separate video.
So all of this may work at this network and then transfer these ladieswear defines how your data should
be sent to the source to destination.
And we need to implement two protocols as a TCP are.
These are the main two transfer protocols and we see what this DCP and UDP supported.
And this stands for also I say in the put numbers.
So if you want to send it to a computer to particular.
Service, there will be a number and on the bottom where the service will be running on, so this transporter
assigns that which protocol to send and also the phone number to send this session there will initiate
the session from these variables spot.
So it makes sure that our we are connecting to the right destination or not.
And this is presentation.
So in what format we should send the data such that the nation could understand.
So in our Prešov or any other format and the application of these the layers of it.
And these are the Navar applications running on the users like browser Ottone user application.
So what this does is.
You just these are the applications and these applications also run some other protocols like the GDP
and DPS and so on, we'll be seeing the protocols later.
But one hour, one way too easy to do.
What are these names?
His.
Well, just remember these words, please do not throw sausages with the other hand, if you hear the
fighting words, you can see be for physical year before that and for for transport.
As for session and for presentation and for application.
So there are so many examples like this, but this is the most famous one, please do not let me go
there.
And this is like a stack of seven letters, although it's a model.
And I want to show you another slide that is considered this as the source.
And this are the destination right from the source.
I had the process of producing and I want to or any user I want to send the data from this computer
to this computer.
So what this application does is it will send this data to presentation.
So this presentation layer adds its own header and it will send the whole data to this session layer,
which contained this presentation header.
And this session in turn adds its own header and sends it to transport.
So by this measure, it at the end you will get all the headers, including all these letters, respective
headers.
And after this is clear, the data is converted into bits and transferred to the destination at the
destination.
Or does this the data content of the headers of these letters?
And what this does is it will identify each letter header and remove it and it will pass the remaining
data to the operator.
These are network layer and then this in turn started for the network header and it was the most, uh,
remotes and send the data to the operators in the same way the data is encapsulated by headers and then
becomes routed at the destination site and the data is sent to the application.
So in this case, this list does not understand that the actual data, it just captures the whole data
and sent to the blue layer.
So make sure you're going to talk about is TCP IP model.
That was a model we have talked of is a theoretically more theoretical model and it does not then not
implement that.
It is very tough to implement that one.
That's what the House did, some modifications.
And in 1960s also this particular don't know exactly.
So this model was introduced.
What they did is they have me do some of this and define this for this question is one this week content
that are in clear and physical data.
So they how much of it got a little grayer and features hubs work at this layer and the network of terrorist
networks create similar layer and transfer to also transfer.
And one important note is you can use this application layer.
There are there is no session and presentation because they have believed that the application itself
can present the data.
I mean, for the data and the specific format and then application itself can initiate a connection.
Right.
So suppose if you say a browser, you in your browser, you will send that request, the hatchetman
file from the server and even you are initiating the connection using the browser.
Right.
That is far from the session.
And the browser is able to decode that fumer and it is showing you need format of the application itself
is doing some presenting work for formatting work for you.
So and also application that includes the application itself and also protocols associated with that
application.
So since applications, modern applications are doing these tasks, they have merged those two years
into application.
So this is a practical model we are using right now.
And the model is only theoretical model.