On Nov 12, 2013, at 1:12 PM, Michael Richardson <mcr+ietf@xxxxxxxxxxxx> wrote: > I'll bet if we had a single IPv4 over IPv6 solution which had a clear > operating cost savings over Dual-Stack, and also over IPv4-only+CGN, that > we'd be at universal deployment of IPv6 already. And if we all had ponies, we could go for a ride together! Seriously, the various solutions that have been proposed are all reasonable technical solutions. There's no strong technical reason to prefer one over another. And the proponents of the solutions will not come to consensus on a single solution. So your choices, really, are many solutions, or none, or let the IESG pick a winner, which I don't think would be a popular move. We could just stand pat with DS-Lite and Public 4over6, but there's demand for port-sharing in locales with fewer IPv4 addresses to burn, and putting all the NAT state in boxes in the data center is expensive. Also, "we'd be at universal deployment of IPv6 now?" Seriously? > I don't really understand why we have so many mechanisms... Perhaps we could > have an IAB plenary presentation on it... or maybe someone could do an ISOC > video like Kathleen did for MILE. This would just be more layer 9. I'd rather we published some specs and got on with our lives. The IESG does not have limitless time to burn on trivia, and I don't think the IAB does either. It's just not that interesting to argue about it. These are transition technologies—they'll be obsolete in ten years.