[lmz]

> That just reminded me of a peer protocol I worked on a long time ago that used other hosts to try to figure out which hosts were getting translated. Kind of like a reverse TOR. If that was detected, the better peering hosts would send them each other's local and public addresses so they could start sending UDP packets to each other,

Sounds similar to STUN, really.

[reincarnate0x14]

If that's the VOIP thing, yes, lots of people came to similar methods. That particular thing was for exchanging state, not VOIP or tunneling, so as long as participant groups overlapped it didn't really need a fixed server to be the middle which was handy for our purposes, although long network interruptions could make reconvergence take a while.

Does make me chuckle that so many people had to be working around NAT for so long and then people are like "NAT is way better than the thing that makes us not have to deal with the problem at all." Just had a bit of NAT PTSD remembering an unrelated, but livid argument between some network teams about how a tool defeating their NAT policies was malware. They had overlapping 10.x.y.z blocks, because of course they did :)