Are video calls also P2P? Can video conference calls be placed? If not, does there exist existing FOSS that does conference calls on a P2P network? Edit: It appears TURN is used.
Yes, Jami calls are p2p whenever possible, and TURN is used when not (e.g. due to overly restrictive firewalls). Yes, Jami supports conferencing. One can add additional participants to a 1-on-1 call on the fly, effectively making it a conference. Alternatively, one can enable rendezvous mode from account settings, in which case incoming calls to that account will be added to a conference (similar to a Jisti room).
I was fidgeting with the tought of something like a overlay multicast network on top of unicast IP, since RFC 1770 was deprecated/never implemented.