Where the U.S. has a cable infrastructure, it has a little more control over CPE and in that case it is actually possible to turn on IPv6 without the users doing anything. Cable providers are better off than DSL providers in terms of upgrading to IPv6. The other thing that's different for the U.S. is the move by Verizon with 4G LTE. They're reinventing most of their mobile services. Verizon understood that if they wanted a coherent mobile network, it had to be IPv6. They wrote it into all of their specs and said that all of their suppliers had to be IPv6. I haven't seen many countries where a carrier has taken such a bold move.
Is last-mile infrastructure the biggest challenge to IPv6 deployment?
Yes. This is one of the hardest problems that our industry faces. Over the last 10 years, we have made the last mile the subject of intense competitive pressure. Revenue per consumer per month is measured in pennies instead of dollars. The issue for them is twofold: One, they have to upgrade their internal equipment, but they are sitting on equipment that they don't want to replace.
The second problem is that the one thing most last-mile access providers absolutely dread is when the customer rings up the call center. It costs a huge amount of money to run a call center, upwards of $60 to have the phone answered. The last thing you want is to have more phone calls. When you introduce a second protocol on the wire, the Internet can appear to go very slow. Sometimes Web pages take 30 to 40 seconds to load. Sometimes in IPv6, you don't get there. So you might ring up the help desk number. Carriers dread more phone calls from the customer. So that's why the last-mile access providers want to wait until their competitors deploy IPv6. They don't want to be at the front of the pack.
You've said it isn't clear which path the Internet will take: IPv4 with carrier-grade NATs or IPv6. Do you still think that's true after World IPv6 Launch Day?