Networking Models

                                            Networking Models

A network model describes the organization of various computers in a network. It describes the way in which individual computers are interconnected in a network.

Client Server Model

We can also say it Server based network model. In this model, a specific computer is known as server which is specially dedicated to provide various services to other computers (called Clients). In simple words, server can be defined as a provider of services and client can be as a requester to services. Client makes a request for any kind of information from the server sand server in turn respond to the client request as shown below.

The most common type of client server arrangement is a LAN composed of microcomputers connected to a network server, which serves to all clients (users) of the LAN.

 
Advantages of Client Server Model

1)         Better performance as compare to peer-to-peer model.

2)       It offers better security because of centralization of resources.

3)       Centralized backup is very easy in this model.

4)       Single password login, means access to all resources.

5)          Supports greater number of users.

Disadvantages of Client Server model:

1.          High cost

2.        A dedicated network administrated is required.

3.        Single point of failure, server goes down, the network goes down.

Classification of Client/Server Architecture

1.   Two tier Architecture:

In the two tier architecture, there exists only two parties, one is the clients and other is the servers. The main advantage of client/server model is the simplicity. But there is a major problem when 100s of clients request the data from the server simultaneously. Every client is waiting for its turn to come.

2.   Three tier Architecture:

It is also called multi tier architecture. In this architecture, there is a middle layer between the client and the server. Its solve the problem of waiting time by clients. It maintains a queue of requests by different clients and clients can do their work meanwhile the server is busy in processing other client’s request. Middle layer forwards the request and server in turn replies to the client.

Peer-to-Peer Model

In peer to peer model, there are no dedicated servers. All computers are equal and, therefore, are termed as peer. Normally, each of these machines functions both as a client and a server. This arrangement is suitable for environments with a limited number of users (usually ten or less). In these models users need to freely access data and programs that reside on other computers across the network.

Advantages:

1.     Simple to design and maintenance.

2.     The network is not totally reliant or dependent on a particular computer.

3.     Linking new computers in a peer to peer network is significantly more straightforward.

4.     Less cost.

5.     No need of dedicated network administration.

Disadvantages:

1.     Security is poor as each system manages itself.

2.     Back up is difficult as data is located on different computers.

3.     Limited users.

4.     Too many password for shared resources.