t suitabil- ity for supporting actual field scenarios is a major goal of OSS through the Java initiative. These systems should also meet performance and scalability for usage in actual field scenarios. Defining OSS through Java APIs and maturing APIs from other sources results in the addition of more complete business scenarios to the demonstration systems. The OSS applications are divided into three fundamental parts by the J2EE application model. The three parts are: Components: The application developed is comprised of a set of components. This makes components the key focus area for application developers. Containers: It provides service transparently to both transaction support and resource pooling. Using containers, component behaviors can be specified at deployment time, rather than in the program code. Containers also provide security in addition to transaction support. Connectors: Connectors define a portable service API to plug into existing OSS vendor offerings. It is a layer beneath the J2EE platform and promotes flexibility by enabling a variety of implementations of specific services. System vendors can conceal complexity and remote portability by implementing con- tainers and connectors. Use of OSS/J has many benefits to different players in the telecom value chain. To equipment vendors, it facilitates integration of equipment with more vendor prod- ucts. Service providers are able to develop agile solution and improve interoperability Fundamentals of EMS, NMS and OSS/BSS using OSS/J component architecture. To software vendors it provides a common API support for across-the-board integration. This accelerates the delivery of new products, lowering integration and maintenance costs. The use of OSS/J will reduce integration costs for system integrators. Various commercial off the shelf (COTS) and legacy applications, both net- work and customer facing, are integrated by the OSS systems. OSS/J initiative works on specific application areas in OSS domain and uses J2EE, EJB, and XML technologies for its