I’ve been working on exactly this for the last week. I just managed to get voice calls working with Coturn, though I haven’t tested it beyond two people yet. I read being behind NAT can cause issues so I’m anticipating some kind of issue down the road. I plan on implementing video, so hopefully I can get it working and upload the full config here. I have Matrix, Synapse, Postgresql, Nginx, and Coturn. Livekit is next.
For now my initial experimental pick is here An example configuration for getting started with Matrix on NixOS — Kim's blog if you want to pick something, seems to works well up to 3 concurrent video-chat users, even if not at a superb video quality. Is raw in Nix terms, not using sops/age or else, just a plain classic non-flakes config.
I choose to avoid PostgreSQL since for a family+friend light usage it’s an extra burden (with potential migrations from a version to another to handle). I’ll add LiveKit and Element Call once I got them working, so far I’ve just starting to read their (very) scarse docs…
PS mobile side this config works for Element Classic, and potentially other clients but not Element X who expect Element Call for conferencing even for a 1:1 call.