overlay network are a good solution to NAT i think, i'd say they should be anonymous but something that's just private like cjdns is pretty good too. there are

overlay network are a good solution to NAT i think, i'd say they should be anonymous but something that's just private like cjdns is pretty good too. there are some performance and latency issues to deal with, but when you overlay you don't have to wait for network operators to fix NAT.