A press conference taking place on Thursday in Miami is expected to mark the last allocation of Internet Protocol, Version 4 addresses by the central authority that assigns them.
The event, which will take place at 14:30 GMT and be shared via webcast, will bring together four nonprofit organizations that coordinate the Internet's addressing system, according to an advisory sent to media on Tuesday.
The Internet Corporation for Assigned Names and Numbers (ICANN), the Number Resources Organization, the Internet Architecture Board and the Internet Society all are scheduled to participate.
The advisory specifies that the event will concern the dwindling number of IPv4 addresses. The total supply of 4.3 billion IPv4 addresses has been nearing depletion for several years, leading to warnings that enterprises and Internet service providers (ISPs) should adopt IPv6, a next-generation protocol with virtually unlimited addresses.
IPv4 addresses are allocated by the Internet Assigned Numbers Authority (IANA), a part of ICANN, in large "/8" blocks of about 16 million addresses each. IANA has allocated all but five of these blocks, and its rules now call for one of the remaining blocks to be handed out to each of the five regional Internet registries (RIRs).
Once the RIRs get those final blocks, they will be able to keep assigning addresses to local enterprises and ISPs but won't be able to go back to IANA for more. Under these conditions, some RIRs are expected to tighten their own rules for handing out addresses.
The Asia-Pacific Network Information Center (APNIC), which earlier this week received two /8 blocks from IANA, has said each of its account holders will only be eligible for one more minimum-sized allocation. APNIC thinks those allocations can continue for about five years. It will hold one smaller block in reserve during that time.