Internet Protocol version six, or IPv6, is an Internet addressing system designed to expand the number of available IP addresses.

WHITEHOUSE: Office of Science and Technology Policy Blog

This expansion is necessary because the current number of addresses under Internet Protocol version four (IPv4) is gradually being exhausted.

WHITEHOUSE: Office of Science and Technology Policy Blog

Cisco Systems is helping enterprises prepare for the migration to IPv6 (Internet protocol version 6) from IPv4, which most of the world runs on today.

FORBES: Uncle Sam Gives Cisco A Boost With New Internet Protocol

The Cisco study also projects that 71 percent of all smartphones and tablets (1.6 billion) could be capable of connecting to an Internet Protocol version 6 (IPv6) mobile network by 2016.

ENGADGET: Cisco: mobile connections will hit 10 billion by 2016, helped by tablet boom

Lou Anne Brossman, marketing director for Juniper's U.S. public sector business, claims her company has taken a lead in getting the government up to speed on hot-button topics like Internet Protocol Version Six, or upgrading networks to the next generation of specifications governing how to send data over the Internet.

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The internet was built on version 4 of the Internet Protocol (IPv4) which has an upper limit of about four billion addresses.

BBC: Net approaches address exhaustion

The problem is that the original version of Internet Protocol (IPv4), on which the bulk of the Internet has been built thus far, has a fixed capacity of 4.3 billion IP addresses.

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IP, which has ended up being called version six (version five was an experimental protocol) was therefore devised by the Internet's top wizards.

ECONOMIST: Internet protocol