Hello everyone welcome back to the computer networks course and today we shall see the basic characteristics of computer networks before we step into the basic characteristics.
We shall set some outcomes of this session upon the completion of this session we will be able to understand.
We shall understand
- what is the quality of service and we shall also understand?
- Why do we need security in computer networks?
There are 4 basic characteristics of computer networks.
We should possess fault tolerance scalability quality of service and security if we say there is a computer network.
And that computer network should be fault-tolerant it should be scalable it should provide quality of service and it should also provide security.
We shall see each of these in a detailed manner firstly fault tolerance.
1. Fault Tolerance
Characteristics of computer networks:
- To continue working despite failures
- And it should ensure there is no loss of service
For example, if we have a computer network.
And if there is a problem inside the computer network but still the computer network should work even after failures.
And thereby there is no loss of service before we go on to this example part you just visualize the scenario imagine you are going home back from your college.
You know very well about the best route to reach your home and you prefer taking this regular best route, unfortunately, there is a blockage.
And you cannot take this route further what will you do now will you go to your college back or you will find the next available route to reach your home.
I guess we all will find the next available route and we will take that route to reach home this is what we call as fault tolerance.
We shall see an example of fault tolerance
Now let us assume that these two entities are communicating with each other this computer and this webserver through switch this wireless router this link this router one router 3 router 5 switches.
And web server, unfortunately, there is failure may be either in the link or this router has gone down.
So this router instead of forwarding the data through this way it forwards the data to router two so that this communication between this computer.
This webserver is not affected because of this failure this is what exactly fault tolerance I hope now you understood why do we need a fault-tolerant network.
- Because we need to work despite failures and
- We need to ensure there is no loss of service
This is what exactly fault tolerance.
Now we shall see the second basic characteristic of computer networks.
It is the ability:
- To grow based on the needs.
- And have good performance even after growth.
If there are 10 computers in a network and if again 10 computers are added to the network.
This network should work as the same even after adding these 10 computers we shall see an example.
For the scalable Network, the best example of a scalable network.
Even this moment many new devices are connecting to the internet.
And communicating with each other’s internet handles.
This very perfectly and always gives hope for the newcomers.
This is what we exactly called scalability in this example assume 100 computers are connected to router 3,
And we expect our computer network to work the same even after adding these hundred devices.
This is what we call scalability and this is the ability to grow based on the needs.
And have good performance even after the growth of the network.
So far we have seen fault tolerance and scalability.
Now we shall see
The third basic characteristic of computer networks
The quality of service:
The ability to:
- Set priorities
- And manage data traffic to reduce data loss and delays
If a router receives two packets at a time or two data at a time and this router should know to which data it should process.
First, this is what we call set priorities.
I shall explain this quality of service in a detailed manner.
With an example have you noticed something is new in this picture.
Which was not there in our previous, it is the voice over IP form Vivo IP stands for voice over IP phone.
And this phone is different from our traditional landline phone.
This voice over IP phone since the voice data through the internet whereas our traditional landline phone.
Since the voice data through the dedicated telephone network.
So this voice over IP phone is like our WhatsApp call our voice data is sent to the destination.
Through the internet but not through the telephone network.
You may be wondering why I have brought in this voice over IP Phone I shall explain to you.
Why I have brought in this voice over IP Phone for a reason.
Let’s assume this guy is sending some email data to an email server through router one at the same time.
There are two guys who are talking over voice over IP Phone.
Through the Internet, the situation is two guys are sending data at the same time.
Where this router one is experiencing both the traffic at the same time.
One is the email traffic another one is the voice traffic that is real-time communication.
Now the question is to which data this router 1 will give priority whether to the real-time communication or to the email data actually route of 1 will process voice over IP phone data.
Why because it is a real-time communication in real-time communication delays are not accepted.
Whereas delays are not a problem in email communication a delay of one second in email communication is not going to hurt the communication.
Whereas a delay of one second in a real-time communication matters a lot and that is why this router gives priority to real-time communication.
Than normal communication when the router experiences two different kinds of data.
At the same time, this router should be able to know which data should your priority.
This is what we call the quality of service the main aspect of this quality of services that it handles the law.
Also, it handles the delay.
Now we shall see the final characteristics of the computer networks.
It is the ability to prevent:
- Unauthorized access
- Misuse or forgery.
And not only prevention Networks should also provide confidentiality integrity and availability to understand.
Why do we need security?
we shall this example
Suppose someone from this computer is sending some confidential information to amazon.com.
Once the data leaves our computer.
It is not in our hand’s Internet has good guys as well as bad guys.
Whom we call as attackers please note attackers are bad guys.
Assume our confidential information is flowing through router 3.
And what if an attacker steals this information from router 3.
- They get access to our computer
- They can misuse
- or they can also involve in forgery
So it becomes an important task for a computer network to provide confidentiality.
That is the data that is not sent just like that as what we had sent.
It means if it is confidential data this data is converted to a different form.
If that form can be understood only by the sender and the receiver at the same time.
There is no modification of data sent should be there that is this network should provide integrity.
Whatever the sender is sending that only the receiver should receive.
So this property we call as integrity attacker always tried to deface.
This web server so that this resource becomes unavailable for access.
It becomes the ultimate responsibility of a computer network to provide security.
Because the network should prevent:
- Unauthorized access
And it should also provide confidentiality integrity and availability.
Conclusion: I hope now you are clear with all the basic characteristics of computer networks.
- A fault-tolerant Network
- A scalable the quality of service and security
Thank you for reading we shall meet again in the upcoming articles.