Hello and welcome back to I see into you one interconnecting Cisco networking devices. Part one
this is Episode 114 OS I model
I am friend Daryl and I will be a structure for this course
The last video one over the TCP I p stack layers in l. A. I'll operate together,
and this episode we're gonna be covering the OS a model.
So learning objectives for this lesson, we're gonna learn the layers of the O S I model
Leave the application layer the presentation later the session, transport network data, Lincoln finally, the physical layer.
And then we're gonna figure out how they relate to the TCP I p model
so quickly. In the pre assessment, we might know what three layers together are expanded in the OS I model, meaning they're grouped together in the TCP model, but their expanded And unless I so go and give you a few seconds to try and figure you to sell it. If you want to go ahead and positive video is always talk to you.
Okay, we'll come back. Hopefully you figured it out. Is the session of presentation application layers.
These are grouped together in the TCP I P model
as just the application layer. Now, if you got physical and data link being together, that is also correct. I'll give you that is just being the link layer in the TPP model.
So some of differences in the models here, if you look off to the right,
we see that all three of the application layers are kind of bound together in the application that presentation on the session.
And then, if you look down in the TPP model in the Internet layer, it's called the network layer in the OS I model.
And then you'll see that the network interface
in the TCP I P model is split up between data link and physical layers.
interesting that all the computers and phones and everything uses the TCP at peace tack on there.
What everyone will talk in the office. I model terminology, meaning, Let's say you have ah layer to switch or you have a layer three switch. You know that it does a little bit of routing.
That's a lot of times. That's how it's talked about, but no one with all the all the devices actually uses TCP I pee stick.
So the always say models the easiest way, The way that I always remember is with pneumonic
programmers. Do not throw away sausage pizza
going from Layer 12 Layer seven.
So application layer gonna start the top. What it does is it provides an interface for the user's programs to interact in network with a specified protocol such as, Let's say Http,
you talked about a little bit about that last lesson.
The presents. A presentation later determines the data formats like images, videos and then the asking text of it.
So session Layer will group bidirectional messages together for the host. So air hose communication.
So the transport layer is kind of the same. Function is the transport layer in the TCP I pee stick that it focuses on data delivery and Eric er correction.
Now the network layer is closely related to the tpp Internet layer and that it defines logical I p addressing
routing supports routing protocols be a e i J R P or
The data link layer defines the protocols for delivering data or a particular type of media
like we'll see your have a layer to switch. It's gonna utilize the Mac address
of your network interface.
Right? Your physical address.
Almost like a serial number. Almost. Say, I guess we'll get into Mac addresses later.
The physical layer, though, is going to find the physical characteristics of the transmission medium being you're looking at your category level of your youth and cabling. You're talking about what kind of watch content of the cabling has, or the light transmission it might have if it's a fiber optic cable.
So it talks about the different standards that these will use.
So the honest I model encapsulation what it does instead of having,
uh, you know, your frames
packets your segments is gonna have what are called the PT use of the protocol data unions.
So you'll see has ah, layer. That's a layer to protocol data unit
is how it's set on the right there.
What is it actually has is the header and trailer plus encapsulated data.
So the Layer three Protocol Day unit will have the Layer four protocol data unit, plus the header of the Layer three.
So quick post it says Here it's just kind of
goes back hold, so flee you can kind of relate this to the TCP I p stack as well, but I will give you a few seconds to figure out which layer of the O. S I model deals with the routing of a packet.
Hopefully, you've figured it out.
It is the network layer which will also be the Internet layer of the TCP I pee stick.
So next episode we're gonna be moving out less than 1.2, which is the fundamentals of Ethernet lands or local area networks.
And as always, if you have questions about this lesson or episodes if you need help or if you just have some computer funny photos, go and send it my way. Look forward. It's senior in the next lesson and thank you.