Comcast Labs and ISC Release Open Source Software to Facilitate IPv6 Transition


Comcast (NASDAQ: CMCSA, CMCSK) and Internet Systems Consortium (ISC) announced today the release of open source software that will help facilitate the industry's transition to IPv6, the global numbering system essential to the continued growth of the Internet. The Address Family Transition Router (AFTR) software is part of a technology that could enable users to access IPv4 content from their legacy IPv4 devices & applications over an IPv6 network. 

Internet Protocol (IP) addresses are numeric identifications assigned to devices, websites, computers and home gateways that let them communicate with each other on the Internet. IPv4 is the protocol being used today, but the current supply of addresses is being exhausted. According to the American Registry of Internet Numbers (ARIN), exhaustion of the pool of IPv4 addresses will occur sometime between 2011 and 2012. IPv6 is the next-generation protocol that can connect a virtually unlimited numbers of devices.  

However, IPv6 addresses cannot communicate with IPv4 addresses, so a variety of transition technologies are being developed to ensure continued access to the Internet during the migration to IPv6. The AFTR Software is one solution that can be implemented by the Internet community to address this challenge. AFTR is part of the IPv6 deployment model known as Dual Stack Lite. This technology is currently being standardized by the IETF. 

"Comcast's core network and back office infrastructure already supports IPv6 today, but the industry's transition to IPv6 will require widespread access to key technologies like AFTR," said Richard Woundy, SVP of Software & Applications for Comcast.  "We're pleased to be working with ISC to provide open source technologies that could benefit the entire Internet community." 

AFTR is the culmination of almost five years of IPv6 research and development by Comcast and ISC and is intended to aid in the deployment of IPv6 on broadband networks.  The complete version of the AFTR version 1.01 software can be downloaded, free-of-charge, starting today at 

"Comcast has been a leader in IPv6 technology as well as a key contributor to the open source community in which IPv6 is based," said Paul Vixie, President of ISC. "We really appreciate Comcast's support as we work to fulfill ISCĀ¹s mission of making top-quality core infrastructure software freely available to everyone." 

In addition to the release of the software, the newly created AFTR Software Forum ( provides the means for direct interaction between the users and developers of the software.  Basic membership in the AFTR Software Forum is free. For more information on Dual Stack Lite, please see

About ISC

Internet Systems Consortium (ISC) is a non-profit 501(c)(3) public benefit corporation widely known for world-class Internet software engineering and network operations. ISC produces only open-source software, of which BIND and ISC DHCP are the two best-known examples. Our emphasis is on Internet core technology. Our widely-imitated Managed Open Source process ensures the quality of this software while keeping it completely open and available. ISC operates high-reliability global networks of DNS root servers (F-root) and authoritative DNS servers (SNS@ISC) both for non-profit and for commercial enterprises. ISC is also very involved in ongoing Internet protocol and standards development, particularly in the areas of DNSSEC and IPv6. ISC is supported by donations from generous sponsors, by program membership fees, and by specific fees for services. For program or donation information, please visit our website at

About Comcast Corporation

Comcast Corporation (Nasdaq: CMCSA, CMCSK) ( is one of the nation's leading providers of entertainment, information and communication products and services. With 23.6 million cable customers, 15.9 million high-speed Internet customers, and 7.6 million Comcast Digital Voice customers, Comcast is principally involved in the development, management and operation of cable systems and in the delivery of programming content. 

Comcast's content networks and investments include E! Entertainment Television, Style Network, Golf Channel, VERSUS, G4, PBS KIDS Sprout, TV One, 11 regional sports networks operated by Comcast Sports Group and Comcast Interactive Media, which develops and operates Comcast's Internet businesses, including ( Comcast also has a majority ownership in Comcast-Spectacor, which owns two professional sports teams, the Philadelphia 76ers NBA basketball team and the Philadelphia Flyers NHL hockey team, and a large, multipurpose arena in Philadelphia, the Wachovia Center, and manages other facilities for sporting events, concerts and other events.