A most elegant TCP hole punching algorithm

TCP hole punching typically requires complex infrastructure like STUN, NTP, and metadata exchange channels to connect two computers behind NAT. This article presents a simplified algorithm that derives all needed metadata deterministically from a single parameter—a timestamp-based 'bucket'—allowing both sides to converge without communication. The bucket seeds a PRNG to generate shared port lists, relying on routers' equal delta mapping property to match local and external ports.