Our look into the world of the Network Operating System (NOS) continues with an examination of the two primary network operating system models currently in wide use today, the peer-to-peer network model and the client/server model. We will touch upon the differences between these two and the centralized, distributed and distributed central network operating system models as well.
Network Operating System Models
To keep things simple we will look at computer networks from the fundamentalist perspective where we can say that there are two models for networks:
The Peer-To-Peer Network Model
In the Peer-To-Peer network operating system, model (see Fig. NOS-1), all nodes are equal. There is no hierarchy and there are no dedicated “servers”.
All of the computers must have Network Interface Cards (NIC) and other network connectivity infrastructure such as cables, hubs and switches just like in the client/server network operating system model. Both the peer-to-peer and the client/server network operating system models use the same cabling, NIC, hubs, switches etc.
Every node/computer on a peer-to-peer network must handle network security and administration for themselves. Yes, this does mean that you will need to perform exactly the same task multiple times, once for each machine. Automation is not the peer-to-peer network operating system model's strong point.
Every user must make the decisions about who gets access to what individually on a machine-to-machine basis (remember no automated administration).
The Client/Server Network Model
With the Client/Server Network Operating System Model a new device known as a server, joins the network. Another difference here is that for most implementations of the client/server network operating system all nodes will need to access the server before resources including internet connectivity become available to them.
In Figure NOS-3 above you can see that logically speaking for the Client/Sever Network Operating System model all roads lead to the server. This is the most basic fundamental difference between the peer-to-peer and client/server network operating system models.
Network Operating System Model Differences
As already stated the biggest difference between the peer-to-peer and the client/server network operating system models is the SERVER. All roads lead to the server (in the logical sense). The server performs the security and administrative duties for the entire network.
Another major difference between the two types of network operating systems is the manner in which the network is constructed. Peer-to-peer networks tend to be ad hoc in the manner of their construction. That is machines join the peer-to-peer network more or less randomly, they will come and go and generally the other machines really could not care less.
The client/server network operating system model is the opposite. Structure usually in some form of hierarchy is the order of the day here. Machines are “aware” of the presence or absence of network members. This become very important when we introduce a special type of server called a domain controller or a name server into the mix.
The manner in which both network operating system models arrange their members is another difference and this is where we will take up the story in “Network Operating System Topologies”. Until then enjoy!
