While some traditional telecom carriers such as AT&T appear to be dragging their feet on deploying the emerging standard known as IPv6, the US cable industry - led by Comcast - is charging ahead on this long-anticipated upgrade to the Internet's main communications protocol.
This progress on IPv6 was evident at a meeting of cable operators and programmers held this fall in New York City that was sponsored by CableLabs, the industry's research and development consortium
"We've been working with cable operators really closely for over two years on getting IPv6 ready for deployment," says Chris Donley, project director of network protocols at CableLabs, which has supported IPv6 in its specifications since 2006. "We've been talking about the operational aspects and making sure that the work we did in 2006 is still relevant to their plans."
CableLabs has hosted two IPv6 summits per year in 2009 and 2010 for cable operators.
"There's very strong support for IPv6 within the cable industry," Donley says. "From the largest operators to some of the smallest, this really is industry wide preparation for the IPv6 rollout."
The most vocal proponent of IPv6 in the US cable industry is Comcast, which is running a public trial of three different IPv6 transition mechanisms that has attracted 7,000 business and residential customers nationwide. Comcast says it will transition its nationwide network to support IPv6 by 2012.
"Only Comcast so far has been forthcoming with their timeline," Donley says. "They are the furthest along and the most public about it, but there is lots of preparation work going on generally in the industry.... There are similar timelines from other operators within the industry."
Donley says other cable operators in the United States, Canada, Europe and Japan will host public trials next year.
"The pace is going to be accelerated," he adds. "We are seeing a lot of attention paid to IPv6 issues, IPv6 testing and IPv6 development."
At its recent meeting, CableLabs invited cable programmers from MTV, Universal Studios, HBO, Turner Broadcasting, NBC and others to discuss the development of IPv6-based content.
"There's been a lot of progress on the network side, but one of the driving factors for IPv6 is going to be content," Donley says. "So we cosponsored this event with the [National Cable & Telecommunications Association] so we could speak with the cable programmers about the need to move content to IPv6 and the need to work together as an industry to maximize the experience of the end customers."
Cable operators and other ISPs are migrating to IPv6 because the current version of the Internet Protocol, known as IPv4, is running out of addresses. 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 five percent 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 including cable operators 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 US cable industry prefers running IPv6 and IPv4 side-by-side in a configuration known as dual-stack, but it is also testing transition mechanisms such as NAT that may be required to keep Internet connectivity up and running during what will be a long upgrade process.
"The message we are sending is that native, dual-stack support is preferred when it's available, but some of the other transition techniques will be supported when necessary," Donley says.