The Internet is running out of addresses using the current version of the Internet Protocol, known as IPv4. IPv4 uses 32-bit addresses and can support approximately 4.3 billion devices.

have already been assigned. The conventional wisdom of the Internet industry is that the rest of the IPv4 addresses will be allocated in 2012.

That's why Web sites like YouTube are upgrading to IPv6. With 128-bit addresses, IPv6 can support so many devices that only a mathematical expression -- 2 to the 128th power -- can quantify its size.

In order to use YouTube's new IPv6 service, users will need an IPv6 connection from their ISPs.

More IPv6 connections should be available to U.S. consumers soon, given that .