I do have the demonstration server operational am considering creating temp accounts for learners in Nessus and WarVOX. SIPp can create a DOS by mistake ( I know, my house did not get calls for a few hours...once)and I already decided not to do a live demo of SIPp or be handing over the keys to that car.
This material will be on top of basic Linux security ( ssh, IPTables, logs, etc...) and needs to be covered as attacks on VoIP are on the increase. The goal is awareness, not proficiency. Any thoughts on VoIP security topics or software I may be missing?