Desktop voice over IP development with PSTN integration

Our design specification for voice over IP field applications has three main targets: the development and distribution of a free and open source application for voice communications over IP networks; the internetwork of this applications with the PSTN infrastructure without expensive equipments and the technology's study for future developments. The application, called Ephone, uses a modular development approach in order to allow the use of different protocols, compression and robust audio transmission algorithms. Because of this approach we are creating a development API, interfacing with the current system, that will allow anyone interested in this subject to change the system's usual operation and also to create new applications related to voice transmission using its platform. We describe an IP voice system and it explains the Ephone's main features and workflows, questions the robust audio transmission as well as the viability of a voice tool quality in packet networks, particularly IP networks.