New voice services are investigated in the fields of Internet telephony (SIP – Session Initiation Protocol) and interactive voice systems (VoiceXML – Voice Extended Markup Language). It is explained how CRESS (Chisel Representation Employing Systematic Specification) can graphically represent services and features in these domains. CRESS is a front-end for detecting feature interactions and for implementing features. The nature of service architecture and feature composition are presented. CRESS descriptions are automatically compiled into LOTOS (Language Of Temporal Ordering Specification) and SDL (Specification and Description Language), allowing automated analysis of service behaviour and feature interaction. For implementation, CRESS diagrams can be compiled into Perl (for SIP) and VoiceXML. The approach combines the benefits of an accessible graphical notation, underlying formalisms, and practical realisation.
Kenneth J. Turner