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Applications offered to end‐users as value‐added services play a vital role in the success of Internet telephony service providers. Today’s standard frameworks for developing them have several shortcomings that motivate the need for novel frameworks. Web services are an emerging paradigm for program‐to‐program interactions over the Internet. This paradigm is a prime candidate for application development in Internet Telephony because it may aid in addressing the drawbacks of today’s standard frameworks. This paper presents a case study that gives insights in the suitability of Web services as a standard framework for the development of conferencing applications in Internet Telephony. The case study includes the definition and the implementation of a novel Web service for conferencing, the implementation of the conference server in a SIP environment, the development of several conferencing applications (including a game), and performance evaluation. Based on this case study, we conclude that Web services are very promising for conferencing application development in Internet Telephony, especially as the performance can be significantly improved with the emerging techniques that are briefly discussed in the paper.

A web service is a software system designed to support interoperable machine‐to‐machine or application‐to‐application interactions over networks. Descriptions enable web services to be discovered, used by other web services, and composed into new web services. Web service composition is a mechanism for creating new web services by reusing existing ones. In order to compose a web service, the right primitive services have to be discovered. A matchmaking technique enables discovering these services. Web services have functional, non‐functional, behavioral, and semantic characteristics. These four aspects of web services provide different key information about the service; therefore they have to be considered for description, matching, and composition. The purpose of this paper is to propose a formal description framework and a formal matchmaking technique that allows describing and discovering web services by considering their four characteristics.

In this paper, the description framework combines two existing languages for functional, semantic, and behavioral description, along with a simple and new language for non‐functional description.

A case study is used to illustrate the description framework and the matchmaking technique. The implementation and performance evaluation of the matchmaking technique is presented. The framework formalizes and integrates the languages in a common semantic domain in order to match and manipulate the different aspects together and formally. Isabelle is used by the matchmaking technique for discovering the partially and fully matched services.

The contribution of this paper lies in the new description framework and the new matchmaking technique.