Le 2012-10-25 00:20, Constantine A. Murenin a écrit :
No dual-stacking is provided; in their slides from [0], T-Mobile USA claims that IPv6-only with NAT64/DNS64 is cheaper than dual-stack with NAT44.
Yes. I forgot to mention another reason why the 3GPP folks like NAT64: most 3GPP equipment vendors charge ISPs by the number of "PDP contexts". Currently deployed equipment can not do dual-stack PDP contexts. So if you want to provide dual-stack to your customers, you need to provide them each with two single-stack PDP contexts, which doubles the amount you end up paying in license fees to equipment vendors.
That's going to change in the medium term when new equipment capable of dual-stack PDP contexts gets deployed. But in the short term, NAT64 looks very attractive.
Simon
