BT are set to have IPv6 (Internet Protocol version six) deployed across their whole network by December 2016.
IPv6 has been in development since the mid-1990s, though deployment has been slow, with IPv6 addresses still only making up 2.6% of UK traffic, a miniscule fraction of internet traffic worldwide. All major broadband ISPs in the UK still use IPv4 as standard, though some customers on Sky and BT already use IPv6 or have IPv6-ready hardware. For Sky, one million customers use IPv6, while for BT the figure is 1.5 million. Some smaller operators in the UK, as well as larger ISPs abroad, have made the switch to default IPv6 already. Many mobile operators also use IPv6 as standard.
IPv6 follows IPv4, the previous addressing system through which the majority of the internet is routed. IPv4 IP addresses have been running out for many years, and are often no longer distributed, with IPv6 addresses being given out instead. Development of IPv6 has come so far as to make the user experience virtually identical – with the majority of users unlikely to notice a difference. Eventually, IPv4 will be retired completely, but in the meantime the two systems are to coexist, and this means some hardware such as routers will need to be replaced or updated.
BT say they have planned to start IPv6 deployment gently. They hope to have 50% deployment by April 2016, with 100% deployment following in December.