OK, great.
In the last lecture, we have seen the introduction to Grierson's multiple axes with collision detection,
which is mostly used in the wild at network, and Clemencia is used for wireless networks.
Now, how the system really works?
Well, the convention method is used in Ethernet and the mechanism it helps to minimize, but it does
not eliminate collisions.
I have already said in the previous lecture that the first step is when a device needs to transmit.
It checks the wire.
If the transmission is already under the way, the device can tell.
This is called a carrier sense.
Now, why did I use the word wire?
Because in this lecture, in this convention method, the medium is actually the wire, whereas in the
case messier method, the medium was wireless medium.
Second step, if the wire is clear, the device will transmit even as it is transmitting as it performs
carrier sense.
OK, so we have finished this step.
We have finished this step.
Third step.
If another host is sending simultaneous need, there will be a collision, right?
The collision is detected by both devices through carrier sense.
Now both devices will issue a jam signal.
Both the devices will issue a jammed signal to all the devices, which indicates them to not transmit
any frames.
Then both of the devices will increment retransmission counter.
Now, this is a cumulative total of the number of times this frame has been transmitted and the collision
has occurred.
So the counter has a maximum number at which the device aborts the transmission of the frame.
And finally, both the device calculate a random amount of time and will wait for that amount of time
before transmitting again.
Now, in both in most of the cases, because both the devices choose random amounts of time to it,
another collision will most probably not occur because the time is not the same.
The time is not the same for both the devices as it can vary.
And that is why this message works perfectly in the Wired network.
This was all for the content and methods.
We have seen two contention methods to summarise.
The two methods are seen as messy and systemically see media works perfectly for wireless networks and
CDMA city works best for the Wired network that is the Internet.
The CEO stands for collision avoidance and the steady stands for collision detection.
That's it, folks, for this lecture.
In the next lecture, we will have introduction to one of the most important servers in the computer
network history, and that is the DHC piece, or that is the dynamic host configuration protocol.
I will see you in the next lecture.