Parlay-based service engineering in a converged Internet-PSTN environment

Abstract This paper examines current approaches to signalling and service interworking between Internet and public switched telephone network (PSTN). It notes that until now convergence between the two networks has for the most part taken place in the transport and signalling layers. Signalling interworking architectures cater for the specific class of telephony-like services and although they can accommodate the extension of the intelligent network's (IN) realm of control in the Internet, they do not provide a generic platform for service interworking. Through the adoption of the Parlay APIs, a way is foreseen for (a) consolidation of telephone service over both Internet and PSTN through the imposition of a uniform call control API while allowing the installed IN infrastructure to be used also for Internet telephony services and (b) for service interworking between telephony-like services and open distributed services in the Internet. The paper proposes a service architecture that can be used as a platform for Parlay-based service interworking while offsetting some drawbacks that the Parlay approach incurs.