Welcome to this lecture in which are going to talk about network topology.
We are going to first discuss the definition of a network topology, and then we will see the different
types of network topology.
Now, just a topographical map is a type of a map that shows the shape of the terrain, the physical
topology of the network is also a type of a map, defined the specific characteristics of a network,
such as where all the workstations and other devices are located and the precise arrangement of all
the physical media, such as cables.
On the other hand, the logical topologies we covered earlier delineate how data moves through the network.
Now, even though these two topologies are usually a lot alike, a particular network can actually have
physical and logical topologies that are very different.
Now, the first apology that we are going to see is the best apology.
Now, this type of topology is the most basic one of all the bunches of technologies, and it really
does sort of resemble a bus, but more like the ones that have been in a wreck anyway.
The bus topology consists of two distinct and terminated ends with each of its computers connecting
to one unbroken cable running its entire length.
Now, back in the day, we used to attach computers to the main cable with wire taps, but this didn't
work all so well, began using drop cables in the place.
Now, even though all the computers on this kind of network see all the data flowing through the cable,
only one computer, which the data is specifically addressed to, actually gets the data.
For example, if the first PC wants to send data to the printer, only the printer will be able to receive
the data because the data is meant only for the printer and not for the notes.
Moreover, the Bush apology is very easy to install if you want to add a new PC, you just have to slip
T into the main cable anywhere you want to connect a device.
Best apology is easy to install, and it's not very expensive, partly because it doesn't require as
much cable as the other types of physical topologies, but it has some drawbacks.
For instance, it is hard to troubleshoot, change or move, and it really doesn't offer much in the
way of fault lines because everything is connected to that single cable.
This means that any fault in the cable would basically bring the whole network down.
Now, you may be wondering, what is the definition of fault tolerance, by the way, for Lawrence?
Is the capability of a computer or a network system to respond to a condition automatically, often
resolving it, which reduces the impact on the system?
For example, if something brings down the fault, tolerance will act automatically to resolve the issue
and then bring back the networks to its original position.
Moving ahead now, we will have a look at this tart apology.
Astarte topologies connections are connected to a central point with their own individual cables or
wireless connections, you'll often find that central support inhabited by a device like a hub, a switch
or an access point.
Don't worry about the storm such as hub and switches.
We are going to see all these storms in the network devices section.
Start apology offer a lot of advantages over the best apology, making it more widely used, even though
it obviously requires more physical media.
One of its best features is that because each computer or network segment is connected to the central
device individually, if the cable fails, it only brings down the machine or the network segment related
to the point of failure.
Now, this makes the network much more tolerant as well as a lot easier to troubleshoot.
Another great thing about to start topology is that it's a lot more scalable.
All you have to do is if you want to add to it a new cable device, just connect the new device to the
central hub or the switch.
And you are done.
As you can see on the screen, all the six computers are connected directly to the hub.
So if you want to add a new computer, you just have to attach the new cable to the hub.
Then start apology is easier to troubleshoot because if one PC fails, we can see that which PC has
is not responding and thus we can troubleshoot why the network is not responding.
But in this case, if the central device fails, then that is a huge issue.
And since it is easy to troubleshoot start topology, more fault tolerance is provided and although
it is called a star topology, it also looks like a bike wheel with spokes connecting to the hub in
the middle of the wheel.
So to sum up the star apology, uh, here's a list of benefits you gain by going with it, new stations
can be added or removed easily and quickly.
Then a single cable failure won't bring down the entire network as it did in the case of both topology.
Then start topology is relatively easy to troubleshoot.
But there are also a couple of disadvantages to using Astarte apology, the first one is the total installation
cost can be higher because if you want to add a new device, you would require new cables.
And since if you want if there are 100 devices in the network, you'll need 100 different cables to
connect to the hub and therefore there is more cost.
And lastly, it has a single point of failure, the hub of the central device.
Now, that's it for this lecture.
In the next lecture, we will cover the ring topology and the topology.