A distributed IMS enabled conferencing architecture on top of a standard centralized conferencing framework [IP Multimedia Systems (IMS) Infrastructure and Services]

In this article we present an actual implementation of a distributed conferencing framework compliant with the IP multimedia core network subsystem specification. The architecture we describe has been realized by exploiting existing achievements in the field of conferencing. More precisely, starting from the IETF centralized conferencing (XCON) framework and based on an open source XCON implementation provided by our research group, we devised a distributed conferencing solution that was implemented as an overlay network of centralized conferencing clouds. The article´s goal is to provide the reader with useful information about our experience with IMS implementation and deployment. We first describe our architecture from a high level design perspective and subsequently analyze it in detail by highlighting the most notable implementation choices