A potential barrier to the development of IoT is the technical limitations of the version of the Internet Protocol (IP) that is used most widely. IP is the set of rules that computers use to send and receive information via the Internet, including the unique address that each connected device or object must have to communicate. Version 4 (IPv4) is currently in widest use. It can accommodate about four billion addresses, and it is close to saturation, with few new addresses available in many parts of the world.Version 6 (IPv6) allows for a huge increase in the number IP addresses. With IPv4, the maximum number of unique addresses, 4.2 billion, is not enough to provide even one address for each of the 7.3 billion people on Earth. IPv6, in contrast, will accommodate over 1038 addresses ? more than a trillion trillion per person.