So, guys, going forward now, let us quickly review the transport layer and its functionality.
So transport layer is also called the socket layer.
In this lecture we will going to discuss that.
What are the goals of a transport layer?
And we will going to discuss about the two famous protocols of transport layer which is UDP and TCP.
So you can see on the right hand side, we have a TCP IP stack and we will going to discuss the transport
layer.
As I said, the two famous transport layer protocols are UDP and TCP, which we shall going to discuss
shortly.
So transport layer goals.
So now let us discuss the goals of the transport layer.
The main objective or the goal of a transport layer is to facilitate the communication, meaning the
data exchange between applications.
Note the word it is applications.
It is not source or destination machine, but it is source and destination applications running on different
machines deployed in the network.
Right.
Transport layer provides to worldwide standardized famous protocols to achieve its goal.
And those two protocols is user datagram protocol, which is abbreviated as UDP and transmission control
protocol abbreviated as TCP.
In fact, there is third protocol called Sctp, which is actually a hybrid of UDP and TCP protocol.
As Sctp protocol inherits some of the properties of UDP protocol and some of the properties of TCP protocol.
But any discussion on Sctp protocol is out of the context of this course.
In fact, the discussion on Sctp is not important at all, as Sctp is not that famous as European TCP.
Once you understand the functioning of UDP and TCP protocol, it is a cakewalk for you to understand
sctp.
So going forward, as I said, that TCP and UDP both have the same end goal and what is that end goal?
Facilitate data exchange between processes.
When I say process, it means applications, right?
But both protocols that is UDP and TCP facilitate data exchange between the two processes in a completely
different way.
So the objective of this course is also to find that what is that different way?
So you can see in the below diagram, the application X is sending data to application Y.
So this transmission of data is actually supported by either UDP protocol or TCP protocol, right?
Now let us discuss in the next slide that how UDP protocol actually facilitate data exchange between
the two processes.
Though next slide we dedicate to the discussion on how UDP facilitate data exchange between the two
processes.
The remaining portion of this entire course is dedicated to TCP protocol and we will discuss how TCP
protocol facilitate data exchange between the two processes.
So you can see that for UDP protocol we are having just one slide, but for TCP protocol we have entire
course.
The reason being that TCP protocol is a very complicated and complex protocol, whereas UDP protocol
is a very simple and straightforward protocol.