N-tier architecture is an extension of previous architectures like Client/Server, Thin-Client in which each of these pieces of software could reside on separate, dedicated and distributed machine.
The fundamental principle of the N-Tier architecture is to promote re-use through the planned use of partitioned business logic in its own distinct re-usable layer.
Our great experience in Client/Server helped us develop N-tier applications specifically large projects. The distributed architecture helps typically for large applications. We built strong expertise for the middle ware i.e; business logic implementation in Microsoft's hot technology COM/DCOM to provide complete, time efficient and scalable solution to our clients. 

Our expertise to use Microsoft Transaction Server (MTS) and Microsoft Message Queue Server (MSMQ) strengthens the efficiency and reliability of the applications we deliver.

The client/server applications are not scalable, are difficult to maintain and enhance due to tight coupling between the presentation layer, business logic and the database access. Overall the two tier applications are not scalable and are not suitable for Internet based applications. With the growing popularity of J2EE framework, the development of an n-tier application became easier and all the negatives of a two-tier application were well taken care. A J2EE framework provides standardized modular components and a complete set of services to those components. More-over application behavior such as security and multithreading are handled automatically.

Using J2EE to develop n-tier applications involves breaking the two-tier architecture into multiple tiers. An n-tier application can provide separate layers for each of the following services - Presentation Layer, Dynamic Presentation, Business logic, and Data base access. A browser takes care of the presentation layer, and JSP / Servlet / XML / SOAP and XSL take care of the dynamic presentation, Session EJB takes care of the business logic and Entity beans take care of the data access using JDBC. The layered approach allows each layer to focus on a specific role -- for example, allowing a Web server to serve Web pages, an application server to serve applications, and a database server to serve databases. With the benefit of an n-tier architecture and QualSoft's strong expertise on the J2EE framework the team at QualSoft can deliver unprecedented levels of value to customers. Contact QualSoft Technologies to learn how QualSoft can help your businesses to do better.

N-tier Applications