> > I really do not understand you. Try in French :-) Because, obviously, > > if it is unicast, it is not multicast :-) > > unicast is a degenerative case of multicast.
Bill, this is emphatically not true for high speed wireless links, such as the upcoming IEEE 802.11n standard. In high speed wireless networks, the physical layer gets tuned between sender and receiver, resulting in huge gains in transmission quality. You can only apply a fraction of these tunings to multicast traffic. There are also some nasty interactions between multicast and power saving. To save power, the stations sleep most of the time, wake up occasionally, and poll the server for any queued data. For multicast, you have to either guarantee that all stations wake up at the same time, which is hard, or accept to effectively replicate the multicast packet for each station. Transmission tuning and power saving are both very desirable. The natural consequence is to try avoid multicast operation whenever possible. -- Christian Huitema -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
