CitiTime: a system for rapid creation of portable next-generation telephony services

We present the architecture, design and experimental research prototype imp lementation of CitiTime, an open system architecture for the rapid developm ent of advanced next-generation telephony services that overcomes some of t he limitations of the current closed PSTN architecture and service model. C itiTime allows communication sessions to be set up over the PSTN, the Inter net, or a combination of both. Services can be provided by multiple coopera ting distributed service providers, some of whom may use third-party softwa re components which can be "plugged in" or even dynamically downloaded from the network as needed. This allows advanced services to be deployed and de livered to users rapidly, a crucial requirement in the increasingly competi tive telecommunications services marketplace. CitiTime is built upon an obj ect-oriented call model called Citi Call Control (CCC) which we have define d as a small set of extensions to the standard Java Telephony API (JTAPI) c all model. JTAPI is designed primarily for centralized, single provider, ca ll center type applications. Our extensions provide support for multiple, d istributed providers as well as advanced services. CCC hides details of und erlying call-state management, protocols and hardware from applications. Th e CitiTime prototype software is currently operational in our laboratory. W e briefly describe its current implementation as well as future work to add ress issues such as fault tolerance. (C) 2001 Published by Elsevier Science B.V.