IPv6 traffic volumes are likely to remain a hot topic as the pressure intensifies for network operators to deploy IPv6, a 13-year-old standard whose primary advantage over IPv4 is an expanded addressing scheme. While IPv4 uses 32-bit addresses and can support 4.3 billion devices connected directly to the Internet, IPv6 uses 128-bit addresses and can connect up a virtually unlimited number of devices: 2 to the 128th power.
The Internet needs IPv6 because it is running out of IPv4 address space. The free pool of unassigned IPv4 addresses expired in February, and in April the Asia Pacific region ran out of all but a few IPv4 addresses being held in reserve for startups. The American Registry for Internet Numbers (ARIN), which doles out IP addresses to network operators in North America, says it will deplete its supply of IPv4 addresses this fall.
DETAILS: Asia out of IPv4 addresses
But as necessary as IPv6 seems, there is a major stumbling block to its deployment: It's not backward compatible with IPv4. That means website operators have to upgrade their network equipment and software to support IPv6 traffic. So far, most have been unwilling to do so because IPv6 traffic has been so scarce.
One of the only regular surveys of Internet traffic is compiled by Arbor Networks, which recently reported that IPv6 represented less than 0.2% of all Internet traffic. Arbor said IPv6 traffic -- both tunneled and native -- had declined 12% in the last six months, even as momentum for World IPv6 Day was building. Arbor gathered this data by surveying six carriers in North America and Europe.
Not everyone believes Arbor's assertion that IPv6 traffic is declining while so many website operators are preparing for World IPv6 Day.
"I did not see this [data], and I am also very surprised if it is accurate," says Russ Housley, chairman of the Internet Engineering Task Force, a standards body that created IPv6. "I am aware of many organizations preparing for World IPv6 Day."