IPTV providers must serve content to their customers during the
period of transition from IPv4 to IPv6. During this period, the
content provider may support only one version of IP while the
customer's receiver device supports only the other. Likewise, the
network between the provider and its customer may include segments
supporting only one version of IP or another.
This document provides an overview of the multicast transition
problem. It also provides an overview of the solution space. The
solution space is characterized by an adaptation function (AF) that
provides an interface between IPv4 and IPv6 multicast domains. This
document also discusses various multicast use cases which may occur
during IPv6 transitioning. These use cases motivate the solution
space discussion and the requirements that appear at the end.