> How do we break the deadlock? That’s where STUN comes in. [...] In Tailscale, our coordination server and fleet of DERP (Detour Encrypted Routing Protocol) servers act as our side channel
Yes, NAT traversal is used widely. It is only needed at the start of the connection to get both firewalls to open ports. The encrypted wireguard tunnel is point to point
> How do we break the deadlock? That’s where STUN comes in. [...] In Tailscale, our coordination server and fleet of DERP (Detour Encrypted Routing Protocol) servers act as our side channel