With the worldwide supply of IPv4 addresses rapidly dwindling, the United States is pulling ahead of its global rivals in the deployment of next-generation Internet services based on the emerging IPv6 standard.
Quiz: are you ready for IPv6?
From the number of IPv6-enabled households to the amount of IPv6 traffic carried by ISPs, the United States has made enormous strides during the last two years. Indeed, the latest statistics indicate that the United States is the global leader in several categories, including the amount of IPv6-enabled users, Web content and networking products. [See sidebar]
"The U.S. has put a lot of effort into IPv6," says Christine Schweickert, senior engagement manager for public sector at Akamai, a leading content delivery network. "Government agencies were putting pressure on the big networking vendors. They were pushing all the major telco providers and requiring them to put IPv6 in their road maps...It was a strategic move on their part."
IPv6 is an upgrade to the Internet's addressing scheme, which was created 40 years ago using a protocol 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 can support a virtually limitless number of devices: 2 to the 128th power. IPv6 is necessary because the Internet is running out of IPv4 addresses. However, IPv6 is not backwards compatible with IPv4, requiring network operators to support both protocols at an added cost.
One sign of U.S. progress in IPv6 is that there are now three U.S. carriers - Verizon Wireless, AT&T and Comcast - that are among the top six ISPs carrying the majority of the world's IPv6 traffic. Around 15% of Verizon Wireless customers, 6% of AT&T's DSL customers and 2.5% of Comcast broadband customers are using IPv6.
"There's no doubt that U.S. ISPs have made significant progress in IPv6 in the last year," says John Brzozowski, chief architect for IPv6 and distinguished engineer with Comcast, which is halfway through its IPv6 deployment. "This is a numbers game, and raw numbers-wise, the U.S. has a big challenge because of the sheer size of our networks. We have the largest, contiguous ISPs in the world, with Comcast being the largest. It's interesting that a Romanian ISP can come out of nowhere and enable IPv6 on 15% of their infrastructure. I say good job to them. But I have thousands and thousands of devices to enable on my network. . . Here in the U.S., we have gotten a lot done in a relatively short period of time."
In terms of producing IPv6 content, no country comes close to the United States. Five of the 10 most popular Websites on the Internet are IPv6 enabled - and they are all run by U.S. companies. These Websites are Google, Facebook, YouTube, Yahoo and Wikipedia. In contrast, Chinese Web properties Baidu and QQ - ranked 5th and 9th respectively in Alexa's global Website rankings - don't support IPv6.
U.S. government Web sites also are leading the push towards IPv6. The National Institute of Standards and Technology (NIST) reports that 8% of the 1,517 federal Web sites that it tests weekly have turned on IPv6 support for DNS, mail and Web traffic, while another 34% of these Web sites are in the process of enabling IPv6 for these three services. While that still leaves 58% of U.S. government sites without IPv6 support, the NIST data reflects more progress than most other countries have made.
"The 42% of [U.S. government] domains that have made some progress towards IPv6 deployment is a significant accomplishment," says Doug Montgomery, manager of Internet & Scalable Systems Research at NIST's Information Technology Lab.
Federal agencies must support IPv6 on their externally facing Websites by Sept. 30 under an Obama Administration mandate. Although many agencies won't meet that deadline, they are making significant progress on IPv6, industry observers say.
Akamai says that 35 federal agencies that operate 1,200 individual Websites are using its dual-stack IPv6 and IPv4 platform to meet the IPv6 mandate. Akamai's network allows these agencies to accept IPv4 and IPv6 requests from users without having to change their internal platforms.
"We will have an additional 300 to 400 federal Websites dual-stacked between now and Friday the 27th," Schweickert said.
Two years from now, federal agencies must support IPv6 on their internal networks under the Obama Administration mandate. Akamai is working on a new service that will allow agencies to use IPv6 to communicate between their edge and origin servers, rather than proxying this network traffic over IPv4 as it is done today.
"When I talk to public sector agencies in other countries, some of them are looking to mimic the U.S. mandate," Schweickert says. "I definitely see the U.S. as the leader on this front, and I see other public sector customers trying to put similar processes in place in their countries to get IPv6 adoption to increase as well."
The emergence of the United States as a leader in IPv6 deployment comes at a time when both Asia and Europe have run out of all but small reserves of their IPv4 address space.
The European Internet registry - RIPE NCC - announced last week [Sept 14] that it had distributed all but its last /8 block of IPv4 addresses, which has around 16.7 million addresses. RIPE NCC has gone into conservation mode and will now allocate only 1,024 IPv4 addresses at a time to European network operators. Asia reached a similar milestone in April 2011.
The United States, however, is relatively flush with IPv4 address space. The American Registry for Internet Numbers (ARIN) has three /8 blocks of IPv4 address space left, which equals more than 50 million IPv4 addresses.
Many U.S. organizations also have large blocks of unused IPv4 addresses that they received at the dawn of the Internet, before anyone realized IPv4 addresses would become so valuable.
Peter Thimmesch, chairman of IPv4 address trading firm Addrex, says carriers around the globe continue to need IPv4 addresses for their dual-stack IPv6 deployments. "Carriers are taking a strategic view: they need to acquire enough IPv4 address space to support their customers for the many years it's going to take to deploy IPv6," he says. "It's about IPv4 and IPv6, not one or the other."