Internet Protocol Version 6: Federal Agencies Need to Plan for Transition and Manage Security Risks, GAO-05-471, May 20, 2005. Highlights.
“The Internet protocol (IP) provides the addressing mechanism that defines how and where information such as text, voice, and video move across interconnected networks…IP version 6 (IPv6) was developed to increase the amount of available IP address space. It is gaining momentum globally from regions with limited address space…The key characteristics of IPv6 are designed to increase address space, promote flexibility and functionality, and enhance security..”
Related resource – National Institute of Standards Special Publication 800-58: Security Considerations for Voice Over IP Systems, January 2005 (99 pages, PDF)