> From: [email protected] [mailto:[email protected]] On > Behalf Of Brian Haberman
> On 5/9/12 10:52 PM, Lee, Yiu wrote: > > Hi Carsten, > > > > Thanks very much for reviewing the document. I just want to add a > point to > > your question about how applications decide when to use this > multicast > > address format. In fact, they don't. Imagine a use case where a > legacy > > IPv4 IP-TV receiver (an app) wants to join a channel which is > broadcasted > > in IPv6. The app will continue to send the igmp-join (say 224.1.2.3). > > How does the IPv4 IP-TV know to join 224.1.2.3? My suggested answers would be: The IP-TV server provider's EPG web site provides the IP-TV with the multicast group address. > How is 224.1.2.3 advertised to the IPv4 IP-TV clients if the content is > generated by an IPv6 source? Does the source need to be configured to > use one of these IPv4-in-IPv6 multicast addresses? The EPG web server detects that the client IP-TV is using IPv4, so it provides the IPv4 address. > > There will be a function in the network which is statically > configured > > that when it receives a igmp-join, it would covert to a corresponding > > mld-join. The IPv6 address in the join message will follow what is > > described in this draft. This Adaptive Function is transparent to the > > application and managed by the network. > > Are you limiting this approach to only mapping at the IGMP/MLD > protocols? > > How does your Adaptive Function know which IPv6 multicast prefix to use > when mapping the IPv4 multicast address in the IGMP Report message to > MLD? This has to be table lookup. The IPv6 prefix for these IPv4 multicast groups is always the same, or the service provider has a table that specifies the IPv6 prefix for use with each IPv4 group. Bert -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
