Every computer, smartphone, server, and modem that is linked to the Internet has its own unique Internet Protocol address, or IP address. This address allows users to find the particular computer.

The format for the IP was standardized in 1977 as a 32-digit binary number. There were 4.2 billion addresses available with this format, which seemed adequate at the time. However, these IP addresses have nearly all been taken.

On June 8, 2011, several large companies will experiment with 128-digit numbers for the first time in an attempt to expand the IP address universe. Old cable or DSL modems may not be able to handle the new long numbers and so will not be able to access machines that use them.