Folks, My question to the community is: assuming a network based IPv6 to IP4 translator is in place (like NAT64 / DNS64), are IPv6-only Internet services viable as a product today? In particular, would it be appropriate for a 3G /smartphone or wireless broadband focused on at casual (web and email) Internet users? Keep in mind, these users have NAT44 today. There has been a lot of discussion about CGN / LSN / and other technologies around the corner. In the mobile network operator space, the lack of IPv4 addresses, both public and RFC 1918, has been very real for a long time. In North America, mobile network operators have numbered subscribers with BOGON space (obvious risk) and relaunched multiple instances of RFC1918 space multiple times within their AS (breaking end-to-end even within their own AS, which is a problem with technologies increasingly moving towards any-to-any SIP and IMS). In any event, we can clearly state the addressing issue has compromised both engineering and business decisions in today's major mobile networks. Both scenarios above require tremendous NAT44 infrastructure. And, future CGN technologies don't give me much comfort that things will get better for the operator or the consumer. So, i have been looking more at offering IPv6-only service with NAT64 translation to access the IPv4 Internet. For the network operator, the NAT44 and NAT64 aggregate network state / number of translation is the same to start, and as more native IPv6 content come on the NAT64 gracefully. In fact, given that Google is IPv6 now, and Google is content leader, moving to NAT64 would actually be a reduction in NET NAT translations. IMHO, any dual-stack solution is not an adequate interim solution since both private and public IPv4 addresses are simply not available or will be soon completely exhausted. Dual-stack will have a role in the future, just like public IPv4 addresses have a role today. Dual-stack will be a required service for users with special requirements (legacy IPv4 VPNs ....) , not average web and email users that account for greater than ~80% of a mobile operator's customer base. I also want to stress that this solution best fits new subscribers and devices, it will not be a solution for Window 98 ... or Windows XP in fact. This draft is helpful in understanding the issues as well as the IETF's work on NAT64 draft-penno-behave-64-analysis-02 Some folks in a lab decided to see what type of user experience can be expected using NAT64 and DNS64 and IPv6-only on the end system -- using commonly available hardware and software that's available today, but different from the kit used for the NANOG IPv6 hour. In this case, there is a NAT-PT box in place of NAT64, they used an open source DNS64 implementation, and a standard WIndows 7 Starter edition netbook. I think the conclusion is that casual Internet use, as a product, is possible today. It is not everything IPv4 offers today, but as IPv6 content and applications come on-line the IPv6 capabilities will exceed what IPv4 could do (no NAT for native flows). Screenshot video below, best viewed in HQ mode. This is just a data point with regard to functionality that is akin to NAT64 / DNS64 that is available today. http://www.youtube.com/theipv6guy