Vint Cerf, known as the "father of the Internet", warns that by 2010 we will run out of IP addresses if we don't take action, as only 20% of the world is currently connected to the Internet. TCP/IP was developed in the 1970s to improve on earlier protocols and became the basis for today's Internet. IPv4 uses 32-bit addresses, limiting the number of available addresses, while IPv6 uses 128-bit addresses to vastly increase the potential number. IPv6 is expected to slowly replace IPv4 as more addresses are needed to support growing Internet usage.