UK ISPs Respond To the Dangers of Using Carrier Grade NAT Instead of IPv6
Mark.JUK writes "Several major Internet Service Providers in the United Kingdom, including BSkyB, Virgin Media, TalkTalk, AAISP and Fluidata, have warned that the adoption of Carrier Grade NAT (IPv4 address sharing) is likely to become increasingly common in the future. But the technology, which many view as a delaying tactic until IPv6 becomes more common place, is not without its problems and could cause a number of popular services to fail (e.g. XBox Live, PlayStation Network, FTP hosting etc.). The prospect of a new style of two tier internet could be just around the corner."
A few of the ISPs gave the usual marketing department answers, but three of them noted that they've been offering IPv6 for ages and CGNAT is only inevitable for folks that didn't prepare for what they knew was coming. Which, unfortunately, appears to be most of the major UK ISPs.
Judging from what I've read about US telcos and ISPs, and the plans I've seen for mobile and broadband access here, it sounds like you have that the wrong way round. We have way more competition and better pricing in the UK.
which is totally what she said
CGN has already happened in countries that were late on the Internet bandwagon and got too few IPs.
I am currently an unfortunate subscriber going through CGN, and let me tell you, the time I spent debugging connectivity issues is mindblowing.
For those who don't understand the extent of the problem, CGN is also called NAT444:
Your internal network has an IPv4 subnet, say 10.17.0.x. Then your router is allocated an IPv4 from your ISP. You think that's your IP, but it isn't. Your ISP itself is running NAT internally, and ultimately your data is being sent through the wire to the wider Internet with yet another IP.
So you have 3 networks: IPv4 IPv4 IPv4
Practically speaking, nothing that acts as a server will work. i.e. none of the modern multiplayer networking stacks work reliably, for example. When testing your PS3 networking, it will say (correctly) that you are screwed because you have a "Type 3 NAT", which is Sony speak for NAT444.