There always seems to be a major engineering project looming on the horizon for cable operators. Two years ago it was the separable security mandate from the Federal Communications Commission; more recently it was the digital transition.

One project that doesn’t seem to get much attention is the transition to IPv6 addresses, but Comcast was in the news earlier this week for its work in this area. For the first time, Comcast hosted the North American Network Operators’ Group’s 46th (NANOG 46) meeting in its home town of Philadelphia.

In the not-too-distant future, a large ISP is going to make a request to a regional Internet registry, such as the American Registry for Internet Numbers (ARIN), for a large block of IPv4 addresses only to find out that there aren’t enough of the 32-bit addresses left. The estimates vary on when this will actually happen, but ARIN sent a letter to major ISPs in April that said the IPv4 addresses will be depleted within the next two years.

On the other hand, IPv6 is coded in 128 bits and brings an almost infinite number of addresses into play.

With the large number of IP devices – such as gaming consoles, laptops, computers and home networking equipment – on its network, Comcast has grabbed the IPv6 bull by the horns.

Comcast had two big announcements at NANOG 46; the first was an end-to-end demonstration of its network readiness for IPv6, while the second announced the availability of its IPv6 transit backbone for Comcast’s wholesale customers.

Barry Tishgart, Comcast’s vice president of Internet Services, said the end-to-end demonstration included sending Netflix movies across Comcast’s IPv6-enabled backbone to a cable modem.

“The backbones are starting to become IPv6 ready, but the end-to-end infrastructure that supports them is pretty new and unique,” Tishgart said. “It’s not just the servers or the backbone, it’s the whole thing, end to end, that we wanted to show worked.”

On the consumer side of IPv6, Comcast plans to conduct trials later this year and into next year.

“The planning for general availability is underway,” Tishgart said. “We’re really considering the best way to roll it out, whereby people who want it can use it and benefit from it. I think the point being is that there are challenges in the home. Infrastructure-wise, there is a lot we at Comcast can do sooner, but the reality is there’s a lack of networking gear and devices to support IPv6 seamlessly.

“We want to not just make sure the thing works technically, we also want to make sure the user experience is there.”

The IPv6 to-do list for Comcast has included making sure all current and future hardware supports IPv6, especially network and security devices. IPv6, which is part of CableLabs’ DOCSIS 3.0 specification, can be embedded as part of a cable operator’s normal refresh cycle in order to be prepared when IPv4 runs its course.

Cable operators also need to work closely with vendors to make sure all of the relevant software can be updated to IPv6.

Tishgart said ISPs not only need to gear up for IPv6, but also the consumer electronics manufacturers of laptops, computers, mobile phones, home networking equipment and other IP-related devices.

“There are lots of things we can do as a cable provider and ISP, but there are other parts of the industry that have to prepare, as well,” he said.

By getting its wholesale transit backbone ready for IPv6, Comcast can serve the needs of customers such as IT hosting company The Planet and online video company BitGravity. The Planet alone hosts 17.8 million Web sites. In addition to BitGravity, Tishgart said Comcast is also working with other content delivery networks, including Akamai and Limelight, to bring IPv6 content to the market.

“Our backbone for wholesale transit is fully IPv6-capable,” Tishgart said. “There are a few others who are supporting IPv6, but maybe not as large as Comcast. The Planet is a good example of a hosting provider that is proactively making its content available in IPv6. [Web hosting and content delivery networks] have to plan their networking environments based on future growth needs.”

While Comcast has mapped out IPv6 strategies on the consumer and backbone side, other service providers still have some work to do. With the Internet being a “network of networks,” other large service providers need to have their backbones ready for IPv6 in order to pass content from one provider to another.

“The message to the industry is get ready,” he said “The last thing you want is to be in a rush or be in a position where this comes as a surprise. It really shouldn’t come as a surprise, and that’s why Comcast is being proactive.

“We’re ready, and there are other backbones across the world that are ready. There’s another set of people who are in various stages of being ready. Then there are some who might not be taking the conversion as seriously, or they have more complexities.”