Object-oriented design methodology based on functional layers for distributed communications systems

Communications systems will have to support diverse services, which will lead to more complicated software within those systems. This will be a problem particularly because of the system's inability to meet required real-time constraints. This paper describes an object-oriented model based on functional layers for switching systems. Our model enables to improve the productivity, maintainability, and expandability of software while retaining its real-time capability of communications systems. To verify the effectiveness of the model, we implemented it on a computer and telephony integration (CTI) system, and provide the Voice over IP (VoIP) functions.