ChaiTime: a system for rapid creation of portable next-generation telephony services using third-party software components

We present the architecture, design and experimental research prototype implementation of ChaiTime, an open system architecture for the rapid development of advanced next generation telephony services that overcomes some of the limitations of the current closed PSTN architecture and service model. ChaiTime allows communication sessions to be set up over the PSTN, the Internet, or a combination of both. Services can be provided by multiple cooperating distributed service providers, some of whom may use third party software components which can be "plugged in" or even dynamically downloaded from the network as needed. This allows advanced services to be deployed and delivered to users rapidly; a crucial requirement in the increasingly competitive telecommunications services marketplace. ChaiTime is built upon an object oriented call model called Java Call Control (JCC) which we have defined as a small set of extensions to the standard Java Telephony API (JTAPI) call model that allows support for distributed providers as well as advanced services. JCC hides details of underlying call state management, protocols and hardware from applications. In our prototype, we have designed a small set of extensions to SIP, called Extended SIP, for supporting advanced services. The ChaiTime prototype software is currently operational in our laboratory. We briefly describe its current implementation as well as future work to address issues such as fault tolerance.