Well, in the previous two lectures, we have seen what a network interface card is and the other devices
which you are going to learn in this section.
Now it's time to move on to the next device that is the hub you have heard many times from me throughout
this lecture and in this lecture, I will tell you more about a hub.
So as you learned earlier, a hub is a device that connects all segments of the network together in
a star topology.
So as the hub has no intelligence, it is a layer one device.
So basically, what is a hub?
It's a device which is used to connect to our network segments together.
So it access center point.
We have seen in the star topology that the central device which connects all the hosts is a hub.
Now in that case, the hub was connected to all of the computers.
Similarly, different network segments can be used to connect together through a hub.
The hub has no intelligence.
What does it mean?
What is a no intelligence device?
Basically, no intelligence device is a device which does not recognize any frames or data packets that
are sent through it, for example.
Or consider a network of having five pieces, let's say A, B, C, D and E.
Now you need to visualize what I'm telling you.
So suppose if ABC wants to send data packet to frame E, so when the data packet passes through the
hub, the hub does not recognize that this packet is only intended for free.
E I'm sorry for host E it randomly sends the packets to all the hosts and that is why it is a normal
intelligence device.
Now each device in the network connected directly to the hub through a single cable and it is used to
connect multiple devices without segmenting the network.
Any transmission received on one board will be sent out to all other ports in the hub, including the
receiving power for the transmitting device, like I explained a couple of minutes ago.
So basically, this means that if one station sends a broadcast to all others will receive it.
Yet on the addressing, found in the frame is different and it is intended only for the recipient.
Now, this arrangement simulates the physical books that the SEALs may see the standard was based upon.
Don't worry about these terminologies, CDMA and CD.
I'm going to explain all these in the upcoming lectures.
So again, do not skip any lecture.
However, if there are there were 20 users on one PC and if suppose one computer wants to personally
chat with another PC, the entire message gets delivered to all the hosts.
This results in the wastage of resources.
We still have electricity and that is why help is not used for today's resources, because in today's
network there are millions of PCs connected to each other and you don't want the message to be delivered
to all of the remaining posts on the network.
So what do you need to remember about how is that?
Hub is a new intelligence device and it is just used to connect all the network segments together.
A broadcast sent out by any device on the hub will be propagated to all the devices connected to it.
You have to remember this because this might be asked in a question where you have to tell the difference
between a hub and a bridge.
So in the next lecture, we'll talk more about bridge.