Google tries to break IPv6 logjam by own example

SAN FRANCISCO--Although it's been hard for companies to financially justify the expense of embracing the next-generation standard for wiring together the Internet, the incentives are now arriving--and Google itself stands to benefit from the resulting democratization of networking.

Google thinks the time is ripe to begin adopting Internet Protocol version 6. The search giant, which handles gargantuan amounts of traffic, has gradually been making more of its Web properties available over IPv6, which despite being defined for more than a decade still is rare compared to the current IPv4.

The company has been gradually making its properties available over the new standard, starting with an IPv6 access to its search engine in March 2008. The range of other Google properties similarly available expanded to include Google Maps last week, said Lorenzo Colitti, a Google network engineer who spoke Wednesday at a Internet Society panel discussion at an Internet Engineering Task Force meeting here.

The big advantage IPv6 has over IPv4 is the number of unique addresses it can accommodate--4.3 billion for IPv4 compared to more than 340,000,000,000,000,000,000,000,000,000,000,000 for IPv6. Although 4.3 billion may sound like a lot, addresses are often allocated in large blocks that mean many aren't generally available, and expert estimates forecast an end to new IPv4 addresses in 2011.

To sidestep the limitations, engineers have come up with patches such as network address translation (NAT) and dynamic IP addresses. But the way Coletti sees things, those fixes reinforce the status quo on the Net: a relatively large number of clients such as PCs or set-top boxes connecting to a relatively small number of servers with the privilege of their own IPv4 addresses. Clients generally retrieve the data from servers but rarely host it on their own.

"This is what the Internet does, but it could do so much more," he said. Moving to IPv6 lifts the limits on what can be done in the future: "We don't know what those applications are going to be. They didn't know in the 1980s that the Web was going to come along."

Competitive advantage for Google?
The future Google wants to enable through IPv6 is a decentralized, less hierarchical one in which any device can reach any other device on the network without relying on server intermediaries.

That may sound odd for Google, one of the biggest powers on the Internet. But remember that Google's core business strength--search--is based on its skill in making some sense out of the chaos of information available on the Internet. A future in which the clout of central gatekeepers is reduced is one in which Google has a competitive advantage.

After all, the company has hundreds of thousands of servers dedicated to the tasks of crawling the Internet for new data and assessing what's most important. To make that assessment, it invests heavily not on objectively evaluating what's on the Internet, but rather on figuring out how to interpret the available signals that everybody on the Internet supplies on their own. And it has a directly related advertising business that funds further work.

For a technical taste of how Google sees the world, peruse The Unreasonable Effectiveness of Data, published recently by the Institute of Electrical and Electronics Engineers and written by Google researchers Alon Halevy, Peter Norvig, and Fernando Pereira.

Yahoo likes Semantic Web technology, in which content is labeled with tags that help computers better understand its meaning, but Google's technology is designed to comprehend a broader, less structured Net, the researchers say.

"The first lesson of Web-scale learning is to use available large-scale data rather than hoping for annotated data that isn't available," the Google researchers said.

Carrot and sticks for IPv6
So why move to IPv6? Colitti offered some incentives and warnings. On the carrot side, he said IPv6 opens the door to new technology impossible with IPv4 and can ease network administration headaches--and you can bet that Google, with hundreds of thousands of servers at a minimum, has plenty of those. On the stick side, he said, building large-scale NAT into networks is expensive and limiting.

"Those devices will be very expensive...and if you do NAT, it's a support nightmare. It's very hard to maintain," he said. Though adding IPv6 support might not have enticed companies with big profits thus far, the full financial equation is more complicated. "Is the avoidance of future costs an economic incentive?"

But in the big picture, Google's support of IPv6 appears to be less a shorter-term concern about administrative headaches and more a desire to see a vibrant, active, open, and adaptable future Internet.

Google's IPv6 support is similar in broad terms to its efforts to build for the open-source Android mobile phone operating system, Chrome Web browser, and new, pervasive wireless Internet access technology. Google executives have justified such work not as a way to directly make money but rather as a way to spur faster development in areas of the Internet where it thinks progress needs to move faster.

"At Google, we believe that IPv6 is essential to the continued health and openness of the Internet--and that by allowing all devices on a network to talk to each other directly, IPv6 will enable innovation and allow the Internet's continued growth," the company says on the Google IPv6 page.

Google isn't alone in IPv6 advocacy. Russ Housley, the current chairman of the Internet Engineering Task Force, envisions every home equipped with an Internet-connected gas meters, thermostats, and other such devices.

"If you have every home equipped, the number of Internet address exceeds the space that is available in IPv4. You just can't do that," Housley said.

Difficult transition
So if IPv6 is so great, why aren't we all using it? Because it's a difficult transition that requires a lot of work across the entire technology industry--not just at Internet sites, but also in operating systems, server software, management tools, set-top boxes, network equipment, and agencies that dole out network addresses.

Networking giant Cisco Systems even has found that typing IPv6 addresses is an issue. The elements of an IPv6 address are separated with a colon, a change from the period that IPv4 uses.

Worse, IPv6 investments aren't rewarded immediately because IPv6 isn't backward-compatible with IPv4. That has walled IPv6 off into a separate domain that couldn't communicate with the mainstream IPv4 Internet, though some work is under way to better bridge the two.

"What is slowing down adoption is that if I want this (one company's IPv6 work) to be useful, I depend on everybody else in the universe to do the same thing," said Alain Durand, director of IPv6 architecture and internet governance at Comcast, during the discussion. However, he did point to some work under way that would make even small corners of IPv6 useful as opposed to an expense with no return.

Google, though, is trying to show that IPv6 is attainable. As well as Google search and Google Maps, the company offers Alerts, Calendar, Docs, Finance, Gmail, Health, iGoogle, News, Notebook, Reader, and Sites over IPv6.

Google also is organizing IPv6 conferences of its own, with its most recent IPv6 conference last week that drew participation from Microsoft, Yahoo, Cisco, Comcast, and the Beijing Internet Institute; China is a big fan of IPv6. It's also urging governments as well as companies to adopt IPv6.

Not rocket science
Colitti said IPv6 isn't rocket science and suggested people begin IPv6 pilot projects. They should be production-ready, but don't need to be built to handle the scale of traffic as the main IPv4 network. Google's own IPv6 work began as a project done in 20 percent time--the time Google engineers get to pursue their own interests.

Administrators whose sites already have IPv6 users should brace themselves for spikes in traffic growth as they bring new services online, though. After the Google Maps IPv6 move, Google's outgoing network traffic over IPv6 tripled overnight, Colitti said. Currently Google has about 150,000 people using the site through IPv6.

Even though the overall IPv6 transition is showing the typically human ignore-it-until-it's-a-crisis behavior, the context for evaluating IPv6 is changing as the IPv4 growth era comes to a close.

"We're right now two to three years away from depleting IPv4 altogether," Richard Jimmerson, chief information officer of the American Registry for Internet Numbers, said at the panel discussion. Late in the last decade and early in this one, some predicted that the IPv4 address depletion is what would cause the move to IPv6, he said. "Those folks who made those predictions are partially correct."

Corrected Aug. 9 with the actual number of IPv6 addresses available.