> NAT was used as a blocking method for all incoming connections for SOHO networks for decades. And so have stateful/SPI firewalls,[1] and with those you don't

> NAT was used as a blocking method for all incoming connections for SOHO networks for decades. And so have stateful/SPI firewalls,[1] and with those you don't need the convoluted rigamarole of STUN/TURN/ICE infrastructure: a whole class of technology that had to be invented to deal with NAT. Meanwhile, if you have globally addressable (but not necessarily globally reachable) IPv6 on your clients all of that goes away, and it's just PCP [2][3] that's needed to hole punch on your CPE. Much less convoluted. [1] https://en.wikipedia.org/wiki/Stateful_firewall https://en.wikipedia.org/wiki/Stateful_firewall [2] https://en.wikipedia.org/wiki/Port_Control_Protocol https://en.wikipedia.org/wiki/Port_Control_Protocol [3] https://en.wikipedia.org/wiki/Hole_punching_(networking) https://en.wikipedia.org/wiki/Hole_punching_(networking)