If you're looking for encrypted and decentralized VoIP, http://retroshare.sourceforge.net/ is one handy solution (and a lot more).
I'm not sure if it can be used with WebRTC clients, or if it's even needed there.
EDIT: @JshWright - Not sure I understand your question, but RS does "real-time voice communication" (besides the other things like chat, messaging, file sharing, forums, channels...)