this lecture is about the computer networks devices and the computer network service is
the network's devices can be the network interface scored the Nick court,
the switch, the excess point
The network interface court is the court
connected. Tow the motherboard
from one side and connected. Tow the network cable from the other side.
It's the network adapter.
It's an interface between the PC and the network cable.
It resides inside the motherboard off a PC.
It establishes the communication with the PC through the device driver.
Any hardware connected tow. The motherboard must have a software driver.
Facilitate the management, the configuration and the performance off this piece of hardware.
This snake court contains transmitter and contains a receiver at the same time.
It's called a transceiver, which is a mixture between the transmitter and the receiver.
The Natural Interface Court can be wired, which means that can be connected to a cable or wireless with an antenna
connected to the air interface and can be both wired and wireless at the same time.
the Hub shares the frames between machines. A frame of data that it's Sunday by machine a toe machine. B is shared among machines C, D and E and all the other machines inside the hub
to reach its destination from A to B.
This means that the hub is a very good chance for sniffing.
composed of a number of ports tow connect several machines.
Each machine is connected to the help through a port. Inside this hub,
the hub works with full duplex communication.
Each machine can send or receive at the same time and at any time on the hub.
The hub can connect machines with mixture off speeds
ranging from 10 Megan 100 Mega one Giga and even Maur. Inside the hub
they help allows. Four collisions is under
can send. Meanwhile, another sender wants to send, which means that both signals from Sander eh
and Sunder Be can meet at the same time inside the hub, forming a jam signal that has no meaning.
And at this point off time, Sunder a and sender be has to re send their messages.
hub is one collision to mean.
The hub is one broadcast. The mean
collisions make the network slow and congested.
Collisions happen when two thunders want to send at the same time,
and their signals ad
as zeros and ones on the media to form something that is neither zero nor one that is a dream signal. And then both machines have to re send their messages
tow. Avoid collisions. Machines connected through a hub
follows an algorithm that it's cold. Cisma City
Cisma City stands for Carrier says multiple excess collision detection.
If a machine wants to send a message over the media, that is the hub,
it first must sense the carrier. Is there another carrier on the media? If there is another carry on the media than this machine that wants to send has to wait for some time
If unfortunately to machines like here in the image
such as a Andi want to send at the same time,
they both sense the media. They both find the media empty at the same time, they both 10% at the same time.
point of time That collision happens. This is the point of time. We're both signals meet on the media, forming something that is meaningless.
What happens when collision happens?
takes place and then a back off algorithm
a weight for a certain time before re sending its message that has collided with another message. Andy waits for another period of time to rescind its measure message that has collided with another message. This off course makes all the machines lose sometime
and makes the network
leads to poor performance. For this letter. Collision is something that we do not like
The switch is one off the network devices
that is a more recent technology than they have
it. Forwards and filters frames
forwards frames among
the ports that want to send
to the ports that want to receive only.
So the switch allows for no collision,
and the switch allows for knows living.
The switch is better in performance and this, which is a more secure technology than they happen.
The switch works off course with full duplex communication. Each machine can send and receive At the same time.
The switch can work with mixture off speeds ranging from hundreds off megabits per second toe gigabits per seconds.
This, which is one broadcast, the mean
but each port. Inside. This, which is a separate collision to meet.
That's why, once more, the switch allows for no collisions and allows for no sniffing
the excess point. This is a wireless device that connects machines wirelessly inside a land. A local area network,
it transmits frames in the air media and also receives frames in the air media.
It links the world this port off the network, so the wire, the infrastructure
the antenna send and receive wirelessly.
Meanwhile, the excess point itself is connected toe
interface that connects the wireless part off the network. So the wired infrastructure off the network
the excess point is one broadcast demean. The excess point off course is one collision domain and allows for collision.
Meanwhile, there is an algorithm that can be followed tow. Avoid collisions
in the air media, which is called Cisma. See a carrier sense multiple access. Collision avoidance.
is the device that redirects packets between networks. It works based on routing table that is toward inside it or built inside it either static or dynamic.
The router divides the network in tow. Several broadcast domains. Each port in the rotor is a separate broadcast to me,
the router devices that were also into several collision the ways
each port in the router is a separate collision. To me,
the service is that can be offered inside the land.
Can't be file sharing that ofhis raring or application sharing.
This is a form off software resources centralization that can be offered through Ln
Ln can share files, data basis and any applications among the user's. Off the land
applications can be games that can be played by the user's existing on this land.
the land can share several hardware peripherals like the printer, the scanner,
even the process er of a certain machine can be shared toe another machine to use.
inside the land can be shared through a storage server that every other machine can access. As a client.
The weather service's differ from the land. Service is the one Service is can be Web service,
can allow four Web browsing, Web searching or accessing the social media.
The one service's can offer e mail service is that can be exchanged among the user's over a wen.
And let's recall here that the Internet
is a wen is the largest one over the Internet.
The Internet is the network of networks.
It's compromising all the lands in the world.
The Internet is a very big wide area network.
The Internet offers the service off file transfers
sharing or file transfer protocols.
The Internet can offer voice schools and can offer video conferencing.
Also, any small when connecting to lands can offer the same service is voice, schools and video conferencing among the user's existing on this matter?
Now we have explored the devices. The service's off a computer network, Thank you.