This tutorial explains the client-server network model. Learn the advantages and disadvantages of the client-server network model and the differences between the client-server network model and the peer-to-peer network model.
Based on how shared resources are managed there are two types of networks: peer-to-peer and client-server. In the peer-to-peer network, shared resources are managed by the nodes that share them. I have already explained the peer-to-peer network model in the first part of this article. In this part, we will discuss the client-server network model.
This tutorial is the second part of the article "Network Architectures and models Explained". Another parts of this article are the following.
Client-server network model
In the client-server network model, shared resources are managed through a centralized database. A centralized database stores all information about the network. Usually, this information includes user accounts, passwords, computer accounts, location of shared resources, access rules, and the hierarchy of the network. The system on which the centralized database is installed is known as the server system.
The following image shows an example of a client-server network model.
Depending on the size of the centralized database and hierarchy of the network, the database can be installed on a single server system or multiple server systems. A centralized database can only be installed on a NOS. A NOS (network operating system) is a type of operating system that is mainly designed for applications that are used to perform networking-related tasks. Microsoft Windows Server, Ubuntu Server, and RHEL Server are examples of NOS.
Client systems are used to access shared resources. A client system provides two types of login access: local login and network login. The local login is used to access the resources available on the local system. The network login is used to access the shared resources available on the network.
A client system stores login information of only local user accounts. When a user uses the local user account to log in, the client system authenticates the login. When the user uses the network user account to log in, the client system transfers the credential to the server system. The server system checks the centralized database and grants login access if the supplied username and password are correct.
Since the login information of network user accounts is stored on the server system, a user can use any client system to log in and access his network user account.
The following image shows an example of this process.
Typically, a server is used for the following functions.
- Authenticating user login
- Restricting unauthorized access
- Controlling what a user can access
- Storing and managing data in a centralized location
- Backing up data regularly
- Creating network users accounts
- Grouping user accounts based on multiple criteria and requirements
- Storing locations of shared resources
- Mapping user accounts with shared resources
- Creating access rules for shared resources
- Supplying network applications to client systems
- Defining client computers from where a user can log in
To perform the above tasks, a server system requires more processing power, memory, and storage capacity than client systems. For example, a file server may use multiple hard disks to store a large amount of data.
Differences between the client-server network model and peer-to-peer network model
The peer-to-peer network model stores user accounts and passwords on the local system. The client-server network model stores user accounts and passwords on a centralized database that can be installed on a single system or a group of systems.
If a device accesses a service and presents a platform to use the accessed service, the device is known as the client. If a device provides a service, the device is known as the server. In the peer-to-peer network model, a device can act as both. It can act as a server to provide a service and act as a client to access a service. In the client-server model, a device has a dedicated role. It can be either a server or a client. It cannot be both.
In the peer-to-peer network model, each device has equal rights. A device cannot control another device in any form. In the client-server network model, the server defines the rights of each client.
The peer-to-peer network model does not require a special operating system and applications. The client-server network model needs a special operating system known as NOS and network applications.
The peer-to-peer network model is easy to set up and does not need an experienced administrator for management. The client-server network model is complex and needs an experienced administrator for management.
The peer-to-peer network is less expensive than the client-server network model.
The peer-to-peer network model provides basic sharing options. The client-server model provides all sharing options.
The peer-to-peer network is mostly used in a home or small office network. The client-server model is mainly used in a business environment.
Advantages of the client-server network model
It stores all critical information in a single place which makes it easier to manage and backup.
It allows an administrator to define access rules for each shared object.
It allows an administrator to control the entire network from a single place.
It is the most secure network model among all available network models.
It is scalable. An administrator can easily add and remove clients from the network.
In this model, troubleshooting is easy.
Disadvantages of the client-server network model
Since it stores all information in a single place, it has a single point of failure. If the server fails, the entire network fails.
It requires a NOS and network applications that cost a lot of money. You can easily purchase a top-end desktop computer for the price of a single NOS.
It requires a dedicated and experienced administer for setup and management.
It is not suitable for home and small offices.
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