May 17, 2010, 3:36 PM — Comcast last week installed the first corporate customer for its new native dual-stack service, which supports both IPv4, the current version of the Internet Protocol, and the long-anticipated upgrade known as IPv6.
Comcast wouldn't reveal any details about the customer, saying only that it is a well-known technology company located in the San Francisco Bay area.
"These folks came and switched to Comcast because we have native IPv6 as part of our commercial offerings for access services," says John Brzozowski, Chief Architect for the IPv6 Program at Comcast. "It is certainly a milestone for Comcast…We have more news to come on this front."
Comcast is conducting a public trial of IPv6 services and plans to complete its transition to IPv6 by 2012.
Carriers such as Comcast are upgrading to IPv6 because the Internet is running out of IPv4 address space. The regional Internet registries said in April 2010 that less than 8% of IPv4 addresses remain unallocated
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.
Comcast is testing three IPv6 transition mechanisms in its ongoing trial:
* Dual-stack, which involves supporting native IPv4 and IPv6 traffic running side-by-side.
* 6rd, a technique developed by French ISP Free that allows for rapid deployment of IPv6 by tunneling IPv6 traffic over IPv4 addresses.
* Dual-Stack Lite, an approach developed by Comcast that uses network address translation to share one IPv4 address among many customers.
Comcast said in March that 5,500 customers had signed up to participate in its IPv6 trials.
Comcast says it encountered no glitches setting up its first customer with a dual-stack connection. "Technologically, it was very straightforward for us," Brzozowski says. "We've planned ahead knowing IPv6 was in our future…It's about timing. It's about planning."