On analytical modeling of IMS conferencing server

The IP Multimedia Subsystem is an architectural framework for delivering multimedia services over an Internet Protocol (IP) network. Originally, it was specified for wireless networks, but has since evolved to incorporate fixed line access as well. It forms part of a Next Generation Network (NGN) which is defined as a packet-based network where the service functionality is independent of the underlying transport technologies. This allows new converged services to be implemented on top of an existing packet switched network. The centralized conferencing framework limits the ability to have large number of participants because of the overhead on the server. One of the possible efficient solution for increasing of server's performance is grouping meeting requests the same video conference and serving them at one time on an edge-proxy. The queuing model with batch exhaustive service and working vacations is constructed and analyzed. The stationary distribution and the formulas for main performance measurements are obtained. In addition, the optimization problem for increasing a server performance is formulated. © ECMS Thorsten Claus, Frank Herrmann, Michael Manitz, Oliver Rose (Editors).