The Design of a Multi-party VoIP Conferencing System over the Internet

In this paper, we present the design of a VoIP conferencing system that enables the voice communication of multiple users in the Internet. After studying the conversational dynamics in multi-party conferencing, we identify user-observable metrics that affect the perception of conversational quality and their trade-offs. Based on the dynamics and the behavior on delays, jitters, and losses of Internet traces collected in the PlanetLab, we design the transmission topology and schemes for loss concealments and play-out scheduling. Last, we compare the performance of our system and Skype (version 3.5.0.214) using repeatable experiments that simulate human participants and network conditions in a multi-party conferencing scenario.