Several approaches are currently being discussed for the convergence of Web-centric and Telecom-centric services. They can resort to a resource-oriented design methodology for defining a set of REST APIs in order to allow communication services on the Web. Our work aims at investigating how Telecom capabilities could be exposed on the web and be accessed through web browsers. The contribution of this work is threefold. Firstly, a resource-oriented service design methodology is adopted to specify a set of REST APIs for communication services (e.g. a voice call service). Secondly, we model the call resource behavior through a finite-state machine notation which accounts for the SIP signaling specifications. Thirdly, we design and develop a web application prototype that implements the REST APIs to provide a communication service which is accessible to web browsers and also interworks with SIP User Agents. This prototype supports also a mechanism based on the WebSocket protocol for handling asynchronous notifications.