On 2012-10-24, Simon Perreault <sperrea...@openbsd.org> wrote: > One use case: ISP who wants to provide IPv4+IPv6 to customers, but does > not have enough IPv4 addresses for everyone, so has to NAT anyway, and > wants to simplify the operation of its edge network by running only one > protocol. > > Quite popular with 3GPP folks since they have zillions of customers and > are already NATing them in IPv4-only, and their handsets all run > applications coded in a high-level language like Java and therefore > support IPv6 by default. The notable exception being Skype... > > As soon as you provide IPv6, you have a huge chunk of your traffic that > is IPv6: Google, Facebook, Youtube, Akamai, etc. So NAT64 is only used > for the remaining mom and pop shops, and www.openbsd.org. And that > fraction of IPv4-only hosts is diminishing and all signs point to that > trend continuing. > > So these 3GPP providers can go from "NAT everything" to "NAT a little" > by deploying NAT64. Why would anyone in their right mind not consider that? > > Simon > >
Another important thing to note here is that with NAT64 the natting _no longer needs to be in the normal network path_, the translation gateways can be off to one side without any special tricks, just normal routing. (Horizontal scaling can even be done by having the DNS64 push out different prefixes). And as more traffic goes to native v6, the load on the NAT64 gateways decreases. VOIP of various kinds over v6 is still a big problem, though I am sure some of the larger networks interested in protocol transition would not see that as a disadvantage ;)
