In a move to test the Internet for its readiness for a future with billions more people and devices networked, web companies including Google, Facebook, Yahoo and others joined their forces.

As it has been reported many times the number of Internet addresses used for most traffic is about to exhaust and it is urgent that all web resources adopt IPv6 which has 4 billion times as many addresses.

"What's at stake is the future scalability and utility of the Internet," says Matthew Ford, technology program manager of the Internet Society, a non-profit group dedicated to the open development of the Internet, which is organizing World IPv6 Day.

"IPv6 is fundamentally about allowing the Internet to scale to meet the expectations and demands of a global population of 7 billion, coupled with increased expectations of how many devices are expected to be able to connect to the Internet," he says.

On Wednesday websites with over 1 billion combined visits a day will join distribution companies to enable IPv6 on their main services. The test will run for 24 hours and will be joined by such companies as Yahoo, Limelight Networks and Verisign among others.

It will be the first global test of IPv6 "in the wild." Previous tests in Germany and Norway showed positive results.

It is estimated that only one in 2,000 users will experience problems, but the aim is to identify unexpected problems and to raise awareness of the issue.