In a customer we are creating conferences as ad-hoc in most of time. In that conferences, we want that a conference ends as soon as a specifed participant leaves the conference. I know, in order to provide that we need to define all participants as guests but one specified participant as a master. But in this case, one specified participant is known but other participants are unknown. So I can not define anything for unknown participants. And I see that they are connecting as a master as default. Is it possible to change it? Is it possible to make unknown participants connects as a guest participant as default?