Hey everybody welcome to the next video.
So in this video we're gonna be going over a high level of what TPP is now TPP can be broken up into
two sub protocols TPP or Transmission Control Protocol and IP internet protocol.
These are the main.
This is the main protocol used to interconnect networks between nodes on public which is the internet
or the private networks.
Now UDP which are going to be talking about next is going to be another one of the main protocols used
however in most cases you're going to find TPP or UDP when you start getting into telecommunications
for mobile devices you start getting stuff like as TTP or SS 7 I'm sorry.
So there's different protocols for different aspects but on a normal packet based network which is what
you're going to run into 90 percent of the time is going to be either TPP or UDP.
Now what's important to understand is TPP uses a client server type model for its communication.
So somebody initiates the connection the client and the one the other end responds which is the server.
Normally this is the case for UDP.
It can go back and forth but we'll talk about that in the next video.
Now TPP itself TPP divides the data like the raw data of the request into packets and then sends each
packet over to the IP protocol so it can do its edition.
Now the reason it breaks this into packets is because of windowing.
Now what we're doing is I'm not going to go too much into it but I want you to look that up and understand
what it is and a little bit more detail now windowing in a nutshell allows only so much data to be sent
across at a time because the other side is expecting only so much data.
So if you send it too much it will reject it and ask for it to be reset.
Now that's the reason it blocks it into.
It's called segmentation is when this is divided into packets and it's also because packets themselves
can only hold so much that I believe at sixty five thousand five hundred and fifty three or something
like that and have to look up the exact number but there is a there is a finite amount of size a packet
can hold.
Now TCB also reassembled the data based into its original form when it reaches its destination.
So the destinations machine will do that.
Now the type of data sent depends on the type of data or the type of data received as the type of data
set.
So for example if it's an HP request it should be the same exact request when put back together after
sequencing.
On the other end and provide the same exact result.
Now each DCP packet is numbered into a sequence that is unique to the transmission set like I was saying.
So when you send something it doesn't get an idea of one.
It gets a unique sequence number that's unique to that transit to that transaction or that connection
that TTP connection.
Because of that it all it knows what what's in what order for that connection.
So if you send something five packets across and the last two that you sent got there first for some
reason because the packets take a different approach each time.
Sometimes they can take the same approach if it's sent really quickly but in some cases you might find
that one packet takes one way one packet takes a different way especially you're going over the Internet.
So these sequencing numbers are allow it to allow the other end to rebuild the packet and it's correct
and intended way.
Now a time to live which is normally an IP based header but I want to mention it here is that the time
to live if TPP if TPP sees the time to live in the packet as later as in it's been too long since it
was sent it will consider dead and ask the sender to rescind this exact packet which is also called
a retransmission when you see when we start looking into packet captures with wire shark you're going
to see a lot of stuff called retransmission.
This is what happens for a lot of reasons.
It can happen because the time to live was out.
It can happen because it was too much traffic on the network so it couldn't send the packet out or the
packet was corrupted whatever the case might be you'll see something called a retransmission.
Now every packet must be acknowledged and this is to guarantee the data is sent.
So if it sends 500 packets it needs to receive five hundred packets for the request itself to be considered
complete now.
IP handles the addressing of the packet with an IP address as well as the MAC address.
This is the following stuff.
Normally keep track the source IP address where it came from the destination is going to in the time
to live.
And there also should be MAC address underneath here which will go over in the next few slides but it's
understand that IP handles the routing and where things are supposed to go.
So when a switch looks at a packet they don't look at the TTP section of the data packet they look at
the IP header which has all of this information.
Now we haven't gone over what a port is per say so I want to briefly talk about this.
So a port is think of it as a software docking point that external entities or nodes machines servers
can talk to a specific process on the machine.
So for example a web server is a process on a machine that has a port that wants to be able to be talked
to from the outside on port 80.
So when you connect to an import 80 the computer that you're talking to will know that you're trying
to talk to this specific service in the services it's designed to handle traffic from the outside.
So the machine forwards the request to the service or the software.
Now software can run at any port you can run a web service on Port ten thousand if you want to however
just understand that there is a common set of services that run on specific ports such as twenty two
point twenty two is SS H port 80 is h TTP port four for three is HDP s.
So there is a common port unless you can just google common port lists and you'll find a large amount
of them.
Now there's things like I said like web servers tend to be over port 80.
So if you go to a web browser and you type in Google e-commerce rating nation that kind of you're going
to it over port eighty or four for three in case of Google and termination you're going to be and you're
gonna end up over four for three but that's because the browser understands and it defaults to eighty
or four for three on its own now a mac address a MAC address or Media Access Control address is what's
used underneath the IP.
So when you have an IP the actual routing is done based on a MAC address.
Now there are some that route based on IP.
However the MAC address is still taken in incarceration where it needs to go.
Now this is this specific address is normally a hard coded into the hardware itself that you're using
so that is whether that's a wireless card or Ethernet card.
Whatever the case is it's on your physical machine.
Now the M's aren't physical but yet they still have a mac address.
So there is a way for software to tell the operating system what the MAC address is.
So you can spoof or fake in a MAC address just like you can an IP address.
So this is an example of what a MAC address looks like.
You may have seen it when we were on the Windows or Linux machine and we did IP config or if config
you'll see that particular address there.
That is your physical MAC address.
Now I believe on Kelly Linux that spoof Mac is the is the application that allows you to change it so
you can spoof the MAC address which is good for trying to gain access to a Wi-Fi that has mac filtering
enabled.
Now the last part about that I want to go over about TCO VIP to every TPP connection must start with
a three way handshake.
This is to allow the machine on the other end or the server.
In this case to know that a connection is being made and that it's going to be expecting some traffic
or some data from this particular VIP session.
Now the way this works is the client sends a sin or synchronization or synchronized packet to the end
node or the server node to ask if a port is open and if there is an availability for a new connection.
Now assuming the target node has the port open and it's willing to accept a new connection it will respond
with a sin or a synchronized acknowledgement packet just just letting the server know that it's ready
to go the client sends back an AK or an acknowledgement packet to the server and now has an active connection.
Others keep alive their sequence numbers that are still included in this and then any data passed using
the same sequence numbers will be referred to in this.
In this particular TI CPI PPI session.
Now this has been IP in a nutshell.
Now there's far more advanced things that you can hit inside of DCP IP.
What I want you to do is take a little bit of time and look online on what it DCP IP packet looks like.
There's the reason I'm not doing that in this particular video is because I want you to take a look
at it.
First we we will be looking at DP IP packets later when it comes to the wire shark section of the of
course.
However take a look at it get familiar with what it looks like.
So you know what to expect.
There's very key distinct attributes that a VIP package will have over something like UDP.