Reply to post: Re: And who told you I want to be measured?

Re: And who told you I want to be measured?

It is not actually so tiny. In some specific areas (for instance, mobile networks in the US) it's >50%. Still too low to drop v4 _yet_, but what if it was 90%? Would you bother adding legacy v4 support to your new mobile service for that last 10%?

As a hypothetical example then: given that 93% of Sky customers now have IPv6, if you were making a service which was aimed *only* at Sky customers then arguably you could make it IPv6.

But what about the costs of locking out the other 7%? Not just lost business from that proportion of the user base, but the cost of handling support calls from people saying "it works for my friend but not for me" or "why can't I access it from my office/hotel?"

This means that it would almost certainly be simpler and cheaper to make it dual-stack and be done with it. If your CTO said to make it IPv6 only, they would (rightly) be out of a job.

Maybe you'd charge v4-only customers a bit extra to cover the costs (which are steadily increasing; v4 addresses aren't free).

They are essentially free, at $10-$20 *one off* cost per address. Compared to the recurrent monthly cost of hosting, or leased lines, or support staff, or hardware renewal or software licences, they are free.

Even if an IPv4 address cost $1000, content providers would still deploy them to get the customer reach. They are happy to pay much more than that for a decent domain name.

In any case, content providers have been sharing IPv4 addresses for years (CDNs, reverse proxies, HTTP virtual hosts, HTTPS SNI). It's easy to do this at the content provider side.

Of course, deploying IPv6 *in addition* to IPv4 shouldn't really cost them that much more. But if organisations like the BBC which are highly regarded for their engineering excellence aren't making their content available over IPv6, who will? And why should they, given that they know all their users have either IPv4 or IPv4+IPv6 capability?

The squeeze for IPv4 addresses is felt acutely at the access ISP side of course. But since almost the Internet runs IPv4, they have no choice but to provide IPv4 access, with or without IPv6.

I don't see Sky turning off IPv4. They *could* decide to share public IPv4 addresses between customers, but as soon as they do that they are into a world of pain when it comes to handling police enquiries, having to log or lock down the port ranges used by each customer.

It seems to me there's a genuine risk of "peak IPv6" - where the majority of the marketplace rejects it, and it ends up as a playground for Google and Facebook. They have enough power between them to keep it going, and probably quite enjoy running their own parallel Internet; but it could end up that a heavily-NAT'd IPv4 is the real Internet and (oddly) IPv6 is the legacy.

Sooner or later, someone is going to propose a 64-bit port number extension to TCP and UDP, and that will be the end of it.