The remaining pool of unallocated IPv4 addresses could be depleted as early as December due to unprecedented levels of broadband and wireless adoption in the Asia Pacific region, experts say.
The acceleration of IPv4 address depletion is putting more pressure on network operators to migrate to IPv6, the long-anticipated upgrade to IPv4, the Internet's main communications protocol.
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IPv4 uses 32-bit addresses and can support 4.3 billion devices connected directly to the Internet. IPv6, on the other hand, uses 128-bit addresses and supports a virtually unlimited number of devices -- 2 to the 128th power.
As of this week, only 6.25 percent of IPv4 addresses remain available to be distributed by the Internet Assigned Numbers Authority (IANA) to the five Regional Internet Registries (RIRs). The registries provide IPv4 addresses to carriers, usually in blocks of around 4,000 addresses at a time.
In the first half of 2010, IANA allocated more IPv4 addresses to the registries than in all of 2009.
"It's moving so fast now that it's hard for us to be current on it any longer," says Richard Jimmerson, CIO at the American Registry for Internet Numbers (ARIN), which provides IPv4 addresses to carriers in North America.
IANA tracks IPv4 address space in blocks of 16 million addresses, which are known in network engineering parlance as a "/8." At the beginning of 2010, IANA had 26 /8s left. Currently, IANA has 16 /8s remaining unallocated.
"We've gone through 10 /8s since the beginning of this year," Jimmerson says. "To put that in perspective, in all of 2009, we only went through eight /8s. It's very possible that the IANA free pool will deplete in December or January at the earliest."
One reason that unallocated IPv4 address space could be depleted this year is that IANA has a policy that states that when there are only five remaining /8s, it will automatically give one to each of the registries and thereby deplete the free pool overnight.
"When we get down to seven /8s, it could be a matter of days for us to get from seven to zero," Jimmerson says. "Once ARIN gets its final /8, our pool could last anywhere from one day to six months, depending on demand…The minute that carriers hear the IANA free pool has been depleted, ISPs will be sure to get their requests in."
While demand for IPv4 addresses remains flat in North America, there has been a huge surge in the Asia Pacific region this year that is likely to remain strong.