A home gateway based multicast transit solution and implementation on DS-Lite

Due to the exhaustion of IPv4 addresses and the development of IPv6 technology, it is expected that IPv4 and IPv6 nodes will coexist for a long time (we call this transition period). Many solutions have been implemented to ensure IPv4 and IPv6 interconnection, DS-Lite (Dual-Stack Lite) [1] is one of them. The current design of DS-Lite covers unicast services exclusively, multicast services are not supported. As a result, it is meaningful to add multicast support to DS-Lite at both user´s home gateway (also called B4, Base Bridge Broadband element) and AFTR (Address Family Transition Router element). At present, some equipment manufacturers and other companies have developed AFTR which supports multicast, but this kind of support on B4 is relatively little. Therefore, to provide a multicast deployment on DS-Lite B4 is very necessary. In this paper, the existing DS-Lite environment and IPv4/IPv6 only multicast technologies are analyzed first, and then a multicast solution in DS-Lite network environment is proposed, along with the implementation details. At the end of the paper, a Sourceforge address is provided, from which B4 implementation code that supports multicast can be downloaded.