Depends on your goals, bittorrent does without STUN servers by coordinating over other peers in the network. Time-based coordination and simultanous-open is ano

Depends on your goals, bittorrent does without STUN servers by coordinating over other peers in the network. Time-based coordination and simultanous-open is another strategy.. And there's IPv6. Local peer-to-peer wifi can probably use multicast for discovery. The situation isn't pretty, but there's more than what WebRTC with its single-use sessions offers.