I don't know about that. Yes, v4 will be around for a long time but considering the oligopolies we have in both eyeball and content networks, ones a dozen or so very large networks switch, there is the vast majority of Internet traffic right there. It will be around for a very long time handling a tiny bit of traffic.
Facebook alone accounts for 25% of internet traffic in the US. Netflix is estimated to be over 20% and YouTube at 10%. So that's 55% of Internet traffic right there. At the other end of the transaction you have AT&T with 15.7 million, Comcast at 15.9 million, Verizon at 9.2 million and Time Warner at 8.9 million (early 2010 numbers). That's 50 million of the estimated 83 million US broadband subscribers. So once three content providers and four subscriber nets switch, that is over 25% of US internet traffic on v6 (more than half the users and more than half the content they look at). Comcast, nor the other large MSOs, are not as monolithic as they may appear from the outside. In most cases the large MSOs are divided into regions that are more or less autonomous and that doesn't count the outlier properties that haven't been brought into the fold of the region
Agreed, V4 traffic levels are likely to drop and stay at low levels for decades. they are in for various, usually cost related, reasons so don't expect a large block of any of those guys to suddenly be at 60% of their users can get IPv6 addresses. While Facebook working over IPv6 will be a big deal you won't get all of their traffic since a significant fraction of that traffic is from mobile devices which are going to take much longer than PCs to get to using IPv6 in large numbers. Also, Netflix is even more problematic since the bulk of their traffic, and the fastest growing segment as well, is coming from Xboxes, Tivos, other gaming consoles, and TVs with enough embedded brains to talk directly. Those devices will also seriously lag behind PCs in IPv6 support.
I don't think the growth of v6 traffic is going to be gradual, I think it will increase in steps. You will wake up one morning to find your v6 traffic doubled and some other morning it will double again.
They'll be jumps, but they will be fairly smallish jumps since both the content maker, the ISP, and the device consuming the content all have to be ready. Since I don't imagine we will see any pure IPv6 deployments any time soon many/most of the IPv6 deploys will be dual stack and so we are still at the mercy of the AAAA record returning before the A record does.
-- Scott Helms Vice President of Technology ISP Alliance, Inc. DBA ZCorum (678) 507-5000 -------------------------------- http://twitter.com/kscotthelms --------------------------------