2 tier and 3 tier architecture in networking

In this article I describe the 2 tier and 3 tier architecture basics for CCNA 200-301 exam. We know the function of server client architecture in computer networking. The client access some services from the server end. The information save in the form of database in the database server. We access the database server via an application and the data can be retrieve or saved in the database server. The method to access the database from a far server are of two types. Which are divided into two types 2 tier and 3 tier architecture in networking.

Cisco three layered hierarchical model in computer network followed by Cisco manufacturer to provide the compatibility among the various hardware of Cisco. There are many manufacturer of computer machine in the market. Initially When computers became single user public computer. The computers communicate with only same brand machines. It happens because there was no any fix standard for data transfer between different devices. It is very difficult to make communication with each other when the hardware are of different brands or company.

OSI reference model in computer network followed by various vendors to overcome this problem. After implementation of OSI reference model in computer network, equality maintains by all manufacturer. In 1970 the Open Systems Interconnection (OSI) reference model was created by the International Organization for Standardization (ISO). The OSI model was meant to create inter-operable network with different manufactured devices. In this article I describe all layered approach of Cisco three layered hierarchical model in computer network. Before understanding the Cisco three layered hierarchical model it is necessary to know about the 7 layers of OSI reference model because the basic work of each layer is described in the OSI reference model. So in this article i describe both the OSI model and Cisco three layered hierarchical model.

Not only hardware, software also not supported for work the different computer brand. It became very difficult for all computer users to working without implementation of OSI reference model in computer network. It is necessary then to make some common protocols for all vendors of computer. Before implementation of OSI reference model in computer network, all vendors implements their own protocols on computer hardware and software.

The Layered Approach in computer network.

The Layered approach was the best way to make equality for all computer devices. Layers are not physical but following some protocols. Protocols are for connectivity, connections, data transfer and more. All manufacturer begin to follow the layered approach for OSI reference model in computer network. The OSI reference model change in TCP/IP reference model and later on Cisco three layered hierarchical model. OSI layer architecture have 7 layers. TCP/IP reference model convert these 7 layers into only four layers. After that Cisco three layered hierarchical model converts these 7 layers into three layers. Some layers combined to work in a single layer.

2 tier and 3 tier architecture in networking

In 2 tier and 3 tier architecture the application server, client and database server topology changed. Before going in deep for 2 tier and 3 tier architecture understand the application and database server function. The user access the database server via any application. The database server can not be change its place and remain always at the back end which is not directly accessible.

The application can be access by two two methods. First is the application can be installed in the client system like MS Outlook. The second method is to place an application server between the client and the database server. The user then access the application server only. The application allow user to provide the required data from the database server. On these two methods the 2 tier and 3 tier architecture in networking developed.

2 tier architecture in networking

2 tier architecture is very simple and easy topology of application and database server. In 2 tier architecture a user can access the database directly from the client system. There is no any mediator application server between the client and database server. The application is installed in the client computer. The user can access the database directly from client.

So there are basically a client application and a database server which create a 2 tier architecture in networking. The user send request from the client application to the database server. The database server accept the client request and response to the request. There may be some authentication methods used between the client application and database server for security reason. We can say the application and presentation layer handled via the client application at the user end.

3 tier architecture in networking

3 tier architecture is little bit critical from the 2 tier. Three stages works in 3 tier architecture these are client system, application server and database server. The application is hosted a separate server which is connected with the database server at the back end somewhere in the data centre. See the image below

In 3 tier architecture the user need to access the application server. The application server provide the data transfer between the client and database server. There may be multiple application servers works for single application which can be handle by a server load balancer (SLB). The function of SLB can be understand by the below image.

The user send a request to the application server to access the application. The application server provide the user interface to the client and connect the database for the client.

In this article I describe the basics of 2 tier and 3 tier architecture in networking. I hope you get something from this small article. You may drop a comment below or contact us for any suggestion or query related to this topic or on this site. Your suggestions are always welcome by us.