IPv6 is the long-anticipated upgrade to the Internet's main communications protocol, which is known as IPv4.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.
Less than 5% of IPv4 addresses are still available as of last week, according to the regional Internet registries that allocate IPv4 and IPv6 address space to carriers. Experts predict that the registries will hand out the remaining IPv4 addresses by the end of 2011, leading to full-fledged IPv4 address depletion.
Once IPv4 addresses are depleted, ISPs must give their new customers IPv6 addresses or use carrier-grade network address translation (NAT) to share a single IPv4 address among multiple customers. Carrier-grade NAT is expected to result in slower performing, more costly and more complicated network services than native IPv6 services.
The issue of where AT&T stands on IPv6 deployment is important because this carrier has such a huge share of the U.S. telecom market.
"Depending on how you count it, AT&T has about 35% of the enterprise market in the U.S.," Posey says.
AT&T's share of the U.S. federal market is even larger, making the carrier's IPv6 product road map a critical factor in whether federal agencies can meet their new September 2012 deadline for supporting IPv6 on their public-facing Web sites.
In the U.S. government's fiscal year 2009, AT&T "was awarded approximately $535 million in prime contracts," says Ray Bjorklund, senior vice president of Federal Sources, a market research firm. "Among AT&T, Verizon, Sprint and Qwest, AT&T's share of prime contracts was about 49%."
AT&T is one of five carriers – along with Verizon, Qwest, Sprint and Level 3 – that have contracts under the U.S. government's Networx program, which will be the primary contracting vehicle for federal agencies to purchase IPv6-based telecom services over the next decade.