The United States could run out of unique Internet addresses to assign to new devices by the end of this year, a telecommunications official
said. Internet Protocol version 4, known as IPv4, provides the dominant architecture for the Internet. It requires devices to have unique identifiers,
known as an IP address, but it only has space for 4.3 billion of those addresses. The recent profusion of mobile devices and the expansion of
Internet services to more homes have quickly depleted available addresses. An upgrade to the Internet’s main communications protocol with more
space, called IPv6, is available, but adoption in the United States has lagged behind Europe, China and other countries. An estimated 94.5
percent of the available IP addresses for IPv4 have already been used, and the remaining 5.5 percent are expected to be allocated among the
Regional Internet Registries by next summer.next year, a telecommunications official said.