We have developed networking as a way to share resources and information and how that's achieved directly
maps to the particular architecture of the networking operating systems that we have been using.
Now, in this lecture, we are going to talk about the most common known application architecture,
that is peer-to-peer architecture.
There are two main network types that you need to know about.
The first one is peer to peer, and the second one is client to server, which are going to see in the
next lecture.
And by the way, it's really tough to tell the difference just by looking at the diagram or even by
checking out like the video of the network, but the differences between peer-to-peer and blind.
So architectures are pretty major, that they are not just physical differences, they are logical differences,
too.
Now, you'll see what I mean in a bit.
So what is a peer to peer network architecture?
Well, computers connected together in peer to peer architecture do not have any central or special
authority that all peers, meaning that when it comes to authority, that all equals, for example,
your group of friends.
Right.
No one has the authority to judge you or to decide who is greater.
But when a teacher enters a classroom, the teacher has the moral authority that is an example of clients
of architecture.
Then the authority to perform a security check for proper access rights lies with the computer that
has the desired resources being requested from it.
Now, it also means that computers existing in a peer to peer network can be applied to machines that
access resources and server machines and provide those resources to other computers.
Now, peer to peer network architecture is perfectly fine for less number of hosts.
But if you're trying to have more than 50 or even 100 computers in a peer to peer network architecture,
then it becomes a tedious task.
If your network is running Windows, Mac or Unix in a local area network workgroup, you have to have
a peer to peer network.
Now, when it comes to peer-to-peer architecture, security is not centrally governed, each and every
user has to remember and maintain a list of users and passwords on each and every machine.
Worse, some of all those important passwords for the same users change on different machines, even
for accessing resources.
It's a total mess.
And since every user has to remember the usernames and passwords of other computers, a lot of memory
is required in this type of architecture.
For example, as you can see on the screen.
This is an example of peer-to-peer network architecture.
Now, Millie, Pluto, Mickey and Louie are four types of users.
And as you can see on the screen, each user is storing the passwords of remaining three beers.
Now, for example, if Pluto wants to access the resources of Mickey and Mickey has to remember the
password of Pluto, this is such a mess.
Now, this seems okay for four computers, but what if there are hundreds, thousands of computers,
then?
Is it possible to store all the information in thousand computers of each and every year?
No, that would take up a lot of time and a lot of memory.
We do not have that much of memory just to store usernames and passwords and to tackle this problem.
Client server architecture is.
Used in today's most of the business applications in the next lecture will have a look at client server
network architecture.