U.S. cable MSO Comcast (News - Alert) has enabled IPv6 functionality across its footprint, allowing the use of IPv6 to deliver IP-based services as the available IPv4 address space approaches exhaustion.

Every device that hooks into the Internet, be it a computer or smartphone or connected refrigerator, must be assigned an IP address for identification and location addressing in order to communicate with other devices. Since 1981, IPv4 has carried the majority of Web traffic and has provided such addressing, but its capacity is finite (about 4.3 billion addresses according to the IEEE (News - Alert)). With the ever-increasing number of new devices being connected to the Internet and the rise of M2M and the “Internet of Things,” the need arose for more addresses than IPv4 is able to accommodate, so IPv6 was developed.

ISPs are slowly rolling it out and carrying more and more IPv6 traffic. So far, according to World IPv6 Launch, AT&T (News - Alert) is carrying the most out of any operator worldwide. Early adoption of IPv6 is widely seen as a future differentiator for ISPs.

"The ability to employ IPv6 across our entire network nationwide is critical to Comcast,” said John Brzozowski, Comcast fellow and chief IPv6 architect. 

The upgrade has been rolled out across Comcast’s entire ARRIS C4 CMTS footprint, supporting a range of deployment scenarios that include cable modem management and dual-stack customer premise equipment (CPE) behind the cable modem. The C4 CMTS also supports a range of IPv6 features, including options for the IPv6 interior gateway protocol (IGP), prefix delegation and prefix stability.

"Over the past two years we've worked closely with our customers to plan IPv6 feature support for our C4 CMTS portfolio," said Todd Kessler, ARRIS vice president of CMTS product management. "We're thrilled to see the success that Comcast has had using our products, first in their IPv6 customer trials, and now across their entire C4 CMTS footprint."