> For peer-to-peer applications, both UDP and TCP hole punching work fine.
Sadly, that's only half correct. Yes, nat traversal usually works to establish connections. But in practice port mappings are not necessarily the same thing as NAT table entries. If your p2p application contacts a lot of endpoints, even from the same source port, this can eventually lead to saturation. At that point you'll get packet drops and ICMP errors.
In other words, on some aftr implementations p2p can lead to resource exhaustion, leading to a pretty bad ipv4 experience.
> Maybe some ISPs will implement the Port Control Protocol [1] at some point, which would allow port forwarding with the DS-Lite NATs.
Some already do. The CPE can forward local mappings to the AFTR.
Sadly, that's only half correct. Yes, nat traversal usually works to establish connections. But in practice port mappings are not necessarily the same thing as NAT table entries. If your p2p application contacts a lot of endpoints, even from the same source port, this can eventually lead to saturation. At that point you'll get packet drops and ICMP errors.
In other words, on some aftr implementations p2p can lead to resource exhaustion, leading to a pretty bad ipv4 experience.
> Maybe some ISPs will implement the Port Control Protocol [1] at some point, which would allow port forwarding with the DS-Lite NATs.
Some already do. The CPE can forward local mappings to the AFTR.