Original subtitles

We want standardization.

The reason why I can take a copper ethernet cable such as this which has a RJ 45 connector.

Now we won't get into the details it's actually got a different name but most of us refer to this as

an RJ 45 connector.

I want to be able to take this and plug it into an HP laptop plug it into it to Shiba laptop plug it

into an ISIS laptop.

We won't worry about pronunciation for now but the moral of the story is I can take this cable and plug

it into different laptops because of this interface has been standardized and different vendors have

agreed to create the equipment to the specification or to the standard that makes life a lot easier.

In the old old days vendors just did what they wanted to.

They developed their own protocols and their own specifications which wasn't good for customers.

It was great for the vendor because if he bought the equipment you were locked into that vendor.

We don't want that as a customer as a customer.

We want to be able to buy equipment from different vendors and they should all be able to work together.

So because of standardization and because of the industry agreeing on specific models this cable can

plug into different vendor devices without any problems.

We take that for granted today but it was not always the case.

Now the first thing I want you to realize is and you probably know this already.

Nothing in life is as simple as it seems.

And people often have different viewpoints and debate often very heatedly about what is right and what

is wrong.

Don't get stuck in those debates for the CCMA exam.

Just know that there are different models different viewpoints.

But there's one model that you need to know for the exam for the real world.

Have your opinion and go with your opinion.

There were different competing groups that were clashing about what was important and which protocols

should win the so-called protocol wars.

So we had the ISI Group with their protocols we had the TTP IP group with their protocols TTP IP is

one basically.

So for a long time we used the so-called over side model to discuss TTP IP protocols.

But the TTP IP protocols is what we use in the real world.

We use IP version 4.

We use TTP we use UDP we use IP version 6 TTP UDP once again we use IP protocols in the real world.

So there's this disconnect if you like between the OS side model and the protocols that are actually

used in the real world.

So now in the new version of the CCMA we have what these called if you like a hybrid model can combined

model of os sy and TTP IP model so don't get confused.

There was originally a four layer TTP IP model.

We have a seven layer OS model but now we've ended up in summary with a five layer TPP IP model.

Five layers but we refer to the top layer as a layer 7 because it originated from the same model.

So I'm going to talk about some of the details now but in summary make sure that when you study for

the exam you understand that there's a TCB IP model.

But today we talk about five layers instead of the original four layers that were discussed in the original

or if C or request for comments requests for comments or a way that people discuss new protocols and

agree on what a protocol should be.

A protocol is basically a way to communicate.

So if I'm communicating with you in English we've agreed a certain way to communicate.

If I suddenly switch to another language and say two hundred funda you won't necessarily understand

what I'm saying because that language uses a different communication stack if you like or a different

way to communicate versus English.

We have to agree on the protocol or language that we're going to discuss.

So RF sees allow us to agree on what protocol will be implemented by different vendors so that it's

kind of standardized in the old old days we didn't have standardized protocols.

Every vendor did what they wanted but that was a total mess because she had different networks that

couldn't communicate with each other.

These days we want to have one network such as the internet that allows us all to communicate with one

another and that works because we've agreed on standards in the industry so different vendors Cisco

HP Juniper etc. will create equipment that can talk to each other based on the standard.

So in summary you need to know TCB IP model which today consists of five models for this currency CCMA

reflects the real world more than say previous models.

We have the OEM model which consists of seven layers don't get hung up on the individual layers and

I'm going to show you this practically using Packet Tracer.

Understand how the layers work you may get questions saying Okay so at which lay of the oversized model

do you find HDP which is a protocol used for surfing the Internet.

If you go to Web sites such as Facebook dot com you'll be using HDP.

Actually today it's a s which is encrypted HDP it's more secure.

That is an example of what we would call a layer 7 protocol but you also need to understand in networking

that we'll discuss devices such as hubs and we'll say hubs or layer 1 devices hubs aren't really used

today but I'm going to discuss them just to give you an understanding because when you use a wireless

network things kind of change with Wi-Fi sex or the latest release of Wi-Fi.

But previously everything acted as a pure hub in the air.

In other words only one person could communicate at a time.

Wi-Fi still like a hub because it's a shared medium that is shared so you need to understand the principles

of hubs.

Even though we don't use them physically today as in connecting cables to a hub but the air in wireless

networks is kind of like a hub.

We have switches which are called Layer 2 devices.

Actually some people would debate where the switches are a thing but we won't get into that.

We have bridges which are layer to devices.

We have routers which are layer three devices and we have what are called Layer 3 switches.

So notice I'm using terms here a one device layer two device Layer 3 device.

We have a layer 4 protocol which could be DCP or UDP and then we have Layer 7 applications such as HDP

FCP TFT P telnet SS H etc..

Don't get hung up on those you need to know those protocols.

You need to know where they fit in the so-called TTP IP model or side model it'll come to you as we

do a whole bunch of laps and I'm gonna show you the protocols practically in Packet Tracer.

You'll see where those different protocols reside or set if you like in the model.