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12 hours 9 minutes
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this is less than 13.1, and this is networking TCP I p basics
in this lesson, we're gonna go over TCP I p basics are the basics of really networking, So there's gonna be a lot of information that we're going to cover in this lesson, but it should lay the foundation and help you for other lessons that will be learning of network devices, different protocols and so forth. So,
like I said, we're going to get started, and this is gonna provide you a basic understanding of TCP I p. So
let's go and get started.
D p I p is used in your home business. The Internet. The world practically operates off of I p networks I P Networks is a critical foundation for networks today.
TCP I p is about moving data from one place to another.
TCP I p is actually two protocols. TCP is the transmission control protocol response for packaging data frames into packets and I p Internet protocol responsive for address ing
teeth. C p i P generally called i p networking or I P networks, or you may even here some people call it i p.
So moving data moving data from one location to another assembling to similar to mailing a package. So think about that concept as we go through this. If you're sending a larger mamma day, no. You use the shipping box to put all your things into it. Or if you're moving a lot of time sitting a lot of items you would put a ship put into a shipping box
the network were sending across is the postal carrier shipping route. The mail truck is Internet Protocol or I p.
The box holds all your data that you're sitting TCP or UDP eyes the type of data that we're gonna be sending. We're gonna talk a little bit about UDP and TCP a little bit later. Okay? So that box that we're sending or really put it in the mail or that frame rather, let's let's break open it up and breaking apart and kind of see what's inside of it.
it usually in that box or that frame, you're gonna have what's called an Ethernet header. Then you're gonna have your payload followed by an Ethan It trailer.
And if we dig that back or peeling a little bit more, that ether. That header is going to be and we open up is doing an I p or I p payload followed by the Ethan A trailer. And if we get going on a little bit deeper into that, we're gonna find it's gonna be a TCP or a TCP payload.
And that TCP payload is gonna be comprised of http data.
So what you're gonna have in this frame that we've kind of broken apart and peeked inside is it could be a request for a web page. The client sent a frame and that frame was traveled by the router on that end.
And it was an http data on package in that in that frame,
that data is transported within i p wth e os a layer lord that the transport layers which are generally gonna find that TCP operates in a sin cops caps elated by the I p protocol
data can be TCP or UDP depends on the application that is needed.
Now Tacy P is connection or ian. It means it's a reliable delivery acknowledges the connection on also has the capability of recovering from errors, and it manages RETRANSMITS and out of or packets So what that means is, when you're sitting data by TCP, it's more of a reliable connection.
It's has a determined acknowledgment
you send the packet on the other end. There's an acknowledgement that that packet was sent,
so therefore it's called a reliable delivery because it acknowledges the connection. It's not more reliable than another, but their reliability comes in as far as the acknowledgment of it. And it also has built in error correction. It can manage its own RETRANSMITS or if a packet is sent out of order.
Now, let's kind of see how that's gonna look. Um, TCP. Like I said, it's connection oriented. So the TCP data comes from the client,
and it goes to the server right there on the right, and that server's gonna send out a TCP acknowledgement back to the client.
Now let's talk about you. T P
UDP is a little bit differently than TCP Ah UDP is user data Graham Port of Protocol
and its connection lis, meaning there's no acknowledgement or no air recovery. Therefore, it's unreliable now. It's not unreliable, meaning that it doesn't work. It's unreliable that it does not provide an acknowledgment. There's no flow control in the sender to tempt determines the amount of the size of the package is being sent.
So you D P just basically sends the data without any acknowledgment.
Now there may be certain situations where that is needed. Application may need just to send that information and not worry about acknowledgment.
But in the applications of that, needing management or confirmation of that that packet was sent or their needs some air recovery. That's where TCP would be used. But if that is not needed, you use UDP.
So let's get back to our mail truck on the I P Protocol. The truck delivers the boxes or the data to the destination address. Now, how do we determine the address? Each house for each apartment here has an address, so it's gonna be many addresses. How do we know where it's gonna go?
Each computer has an I P address, just like each apartment or building hasn't an address
now. But again, if your love dealing one of apartment complex or a server with many service is how do you determine where those boxes will go? We determine it by what's called ports.
Ports are used to deliver boxes to an application or data or frames to an application. Imports are different. Applications will have different number. Ports are numeric ports. Assigned to them, such as Port 80 is Web traffic for 43 maybe secure Web traffic
5 87 is a different type of application. 25 is a male application
as well as 53 is a different application. So that data was sent from the client, and now it's arriving at his destination. And now it's going to be broken up to what port is going to. So just like in a mailing a letter, you're gonna man letter to an address in that address. That package, or that letter will make it to that address.
But instead of going to just that one address, amazingly, go to Apartment four. Apartment five, Apartment six.
Same thing here.
Each computer on the network and on the Internet has an I P address. You're sitting that data to that destination I p address, but within that letter R, that box that you sent them, there's going to be different application needs. You may be sending a packet of data that's Web traffic, so to Goto Port 80
mail traffic go to port 25.
So that's how that would work in the networking scheme.
Then you have something called I P V four sockets Server I P addresses the protocol on the server application poor and the client I p. Address protocol In the client number. All is a socket
imports. Let's talk a little bit about ports.
Now there's something called non ephemeral or temporal reports. These are permanent ports assigned to certain applications,
and these non informer or non temporal reports are reports zero through 1000 and 23 these are usually for a service on on a server.
Then you're gonna have it from reports and these airports from 1024 to 65,535. These are temporary port numbers. These are determined by the client. These do not normally have a service assigned to them.
TCP and you deport reports can be any port between zero and 65 5 35
Most application on servers used Nani from reports now. Be aware this may not always be the case. Applications can use different ports, but that application that you using need to know the port that it's going to be using. So say, for instance, what I mean by that. ISS Web traffic is generally Port 80
that is generally and commonly known in networks and applications and devices.
If someone wants the transmission data to a Web, um, other than Port 80 the application of suffering needs to know what port that's being sent down, because generally it's going to be looking for and listening for that data on Port 80.
So service were application ports are well known ports. TCP ports are not the same as you DP ports, meaning you can see in Port Ah data to a port in TCP and also sinned
data to that same port, but in UDP, in her two separate paths. So keep that in mind as well.
So let's look at an example how this would come about how this would work of a client sinning, a server data, but three different streams, but all to the same direction or done destination.
So we have Web server traffic on Port 80 invoice or a P traffic, UDP Port 5 50 60 and a mail server, TCP 1 43
So the first dream is the http data on the source i p address from the client's gonna be 1 92 That 1 68 1.20
and the destination is gonna be sending it to is the server 192.1 68 1.1.
So three client will send this packet and use an arbitrary port to send this out. And the sore sport it chose was gonna be 2000 and three,
but the destination port is going to his own. A server is Web traffic. That's going to destination Port 80.
So the server gets the packet. Port 80 in reviews. The http data is gonna send acknowledgement back using the source port of the client, which is 2003 and announcement that it got that at that data
VoIP or over I p. Same thing on the source. I p addresses the client 1 92.1 68 1.20
and the destination is going to is one I 2.1 68 1.1, which is the server.
So it's going to send it out, and it's sort forces using is gonna be 6008 but its destination port that this packet is going to is going to be 50 60 again because this application specific
the server will get that void traffic. And it will respond back to the client on the sore sport that the client sent that data firm, which is gonna be 6000 and eight.
One more example is gonna be the mail service. Same thing the client is sending the server information from its I p address of 1 92.16 th not one about 20. And his destination is gonna be the server whose I P addresses 1 92.1 68 1 down one.
Now the source sport is going to use for that application to be 3001. So it since that data over to the server and the server receives it on board 1 43 But it's gonna respond back to the client on its source port. Did they grab the 3000 won?
So therefore, there you have it. The client is going to send information looking for a specific port on the server, but it's gonna be using an armor Trey port to to send it out
the server. Another hand will receive that and the application specific port. But we're respond back to and talked back to the client on the sore sport that it used.
Okay, so that was a lot of information on T C P I p basics. So that's gonna prepare you for the next class is coming up. And the a lot of learning and the networking Siri's here. So that's the end of this lesson, and we will see you in the next lesson.
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