Abstract
OpenH323 is an open source H.323 implementation that has been ported to IPv6. In this paper we briefly introduce the library architecture and the performance citeria with which the ported version should be evaluated. We then present a variety of experiments that we conducted in order to comparatively evaluate the IPv4 and IPv6 protocol stacks. We also present the results of some initial experiments comparing IPv4 and IPv6 performance under congested network links and the conclusions that they lead us to.