A new system, IPv6, would use 128-bit numbers, allowing for an almost infinite amount of IP addresses. So far, however, adoption has been slow.
If adoption of the new system doesn't happen soon, Google Internet evangelist Vint Cerf warns that a "black market" for IP addresses would start, taking "away from the decentralized nature of the Internet."
"Without IPv6, the Internet's expansion and innovation could be limited," also notes American Registry for Internet Numbers president and CEO John Curran. "Delaying IPv6 deployment may strain the work of Internet operators, application developers, and end users everywhere."
Google is one of few companies that already puts all its services on the IPv6 protocol, with Facebook being another notable company.
Verizon and Comcast, two of the largest ISPs, have begun testing the protocol, as well.