Abstract: A service architecture for the rapid development of next generation telephony services that overcomes the limitations of the current closed PSTN architecture and service model. In this architecture services are provided by multiple cooperating distributed service providers. This architecture is built upon an object-oriented call model which is defined as a small set of extensions to the standard Java Telephony API call model. This new object-oriented call model hides the detail of the underlying call-state management protocols and hardware from applications.