Big Cable Operators Start Phasing in IPv6 Service for Subscribers

With the North American regional Internet registry expected to exhaust its supply of IPv4 address blocks in the next few months, Comcast, Time Warner and Cox are all scrambling to upgrade their networks, cable headends, plant and home equipment and customers from the older IPv4 standard to IPv6 as quickly as possible. They're also pushing consumer electronics manufacturers and Internet content providers to upgrade their devices and websites to IPv6 capability as well.

In public presentations at industry conferences and recent interviews, executives of the three companies detailed their progress on IPv6 and laid out their strategies for transitioning to the new IP addressing scheme in 2013. They also noted some of the key challenges they still face in bringing their operations up to speed.

All three are rolling out IPv6 using the Native Dual Stack method, essentially deploying IPv4 and IPv6 side-by-side throughout their networks. Cable technologists generally view Native Dual Stack as the most graceful, effective way to introduce the IPv6 protocol while continuing to support IPv4 for existing subscribers and devices. But industry experts say Native Dual Stack is usually the most expensive method as well. As a result, some cable operators say they're at least considering such cheaper transition strategies as tunneling and Carrier-Grade Network Address Translation, or NAT444.

Comcast is clearly the most ambitious and aggressive champion of IPv6 among cable providers, said market analysts. In fact, Comcast -- led by John Brzozowski, a distinguished engineer and chief architect for IPv6 at Comcast -- has been one of the world’s leading proponents of the new protocol, pushing it in one industry conference after another. “Everyone in the world is listening to what Comcast is saying,” said Stephane Bourque, founder and CEO of Incognito Software, a leading designer of device provisioning and network management software. “John has been all over the world a number of times in the past few years."

Comcast launched its first operational trials of IPv6 in January 2010. The trials, which involved more than 7,000 subscriber volunteers, tested the use of Native Dual Stack technology for accessing several key Comcast websites, including Comcast.com, Comcast.net, Xfinity.com and Xfinity.net. Comcast then expanded its trials of Native Dual Stack in a number of locations throughout the country, including Littleton, Colo. The company also conducted field tests of the 6RD and 6to4 tunneling methods in several markets, including Philadelphia and Denver.

Based on those tests, Comcast embraced Native Dual Stack as the main, if not exclusive, way to go. “Native Dual Stack performance and experience is superior compared to tunneling,” Brzozowski said, and customer-premises equipment “support for Native Dual Stack is starting to increase.”

Comcast has introduced IPv6 commercially in numerous markets. Starting with Chicago, the San Francisco Bay area, south Florida and southern New Jersey in early 2012, the company has now rolled out the newer IP addressing protocol in at least a third of its broadband network. That would equate to about 6 million users, if they all had the capability turned on. Brzozowski said Comcast is “happily on our way to nationwide IPv6 deployment” by early- to mid-2013. “Our expectation is that we'll have some nationwide [IPv6] capabilities in the 2013 time frame."

Comcast also upgraded two of its major Web portals -- the subscriber website Xfinity and TV Everywhere hub XfinityTV -- and the Comcast customer support forum to the new Internet addressing scheme. Comcast said it made the “critical move” in tandem with its content delivery network vendor, Akamai Technologies, and is gearing up to add support for native IPv6 for all its other key websites.

Time Warner has not been far behind in rolling out IPv6. Lee Howard, TW director-network technology, also has been a vigorous proponent of the new IP addressing scheme for the last few years. Howard said Time Warner did small IPv6 field trials in several undisclosed markets early last year, followed by field trials in all six cable regions in the spring. It then began pilot commercial launches later in the year, with many more deployments expected in 2013.

Howard said Time Warner Cable sought to put at least 100,000 of its broadband customers on IPv6-capable networks by World IPv6 Launch Day last June, meeting the Internet Society’s goal of each network operator enabling at least 1 percent of its broadband subscriber base for the new protocol. Howard argued that the goal was more ambitious than it appeared because only half of the company’s subscribers have a computer operating system that supports IPv6 and most home routers don’t support IPv6. He said about half of the cable modems and 30 percent of the cable modem termination systems (CMTS) in Time Warner Cable’s network supported IPv6 as of World IPv6 Launch Day.

Time Warner also adopted Native Dual Stack as its main, if not exclusive, transition method. Although the company hasn’t ruled out other methods, officials don’t see the point of delaying actual IPv6 deployments by using tunneling and other techniques. “I can’t say there are not circumstances under which we wouldn’t use a different transition strategy,” Howard said. “But since native IPv6 is our long-term strategy anyway, it makes more sense to do that now."

Cox has not been as ambitious or aggressive as the two larger operators. As a result, it doesn’t intend to roll out IPv6 to all of its broadband subscribers nearly as quickly as either Comcast or Time Warner. But Cox has already started delivering IPv6 to more than a dozen commercial customers who take optical services, according to Cox officials. The company rolled out IPv6 to commercial subscribers after starting field trials with Cox Business customers in fall 2010.

Cox started doing small field trials in several undisclosed markets early last year and hopes to start extending IPv6 service to residential customers in pilot markets this year. But, unlike Comcast and Time Warner, Cox has not expanded beyond trials yet, largely because of issues with its CMTS devices. “Our biggest challenge continues to be the lack of IPv6 feature parity and stability when it comes to our CMTS platform, limiting us from expanding our V6 trials,” said Bill Coward, IPv6 lead architect for Cox. “However we plan to ‘keep swinging’ with friendly-only CMTS-based V6 Internet trials throughout 2013 and will make V6 available to the public as these trials demonstrate stability and supportability.”

Cox also has embraced Native Dual Stack as the transition method of choice. With its own IPv4 address supply not slated to run out until mid-2014, the company has no plans to deploy any of the other transition techniques yet. But, Howard said, Cox is working with its equipment and testing vendors to “measure and document the effects of NAT444 within our network” in case that technology is needed as well.