* rrt@research.telcordia.com (Rajesh Talpade) [Tue 09 Jul 2002, 17:28 CEST]:
So why cant the data and control plane be separate for content delivery? Use multicast for the data part, but stick with unicast for the control.
RealPlayer for one does this, AFAIK. (Otherwise they wouldn't be able to charge those extortuous license fees for the server, of course)
Of course the ISPs will also have to somehow separate the data and control plane, so their billing issues with multicast can be addressed...
It probably costs more to send/receive a multicast packet than a unicast one, but there is a cutoff point at a certain (hopefully small!) number of listeners that will vary from network to network and from stream to stream... "Issues" might not be strong enough a word - which would also help explain why not many networks have it in their product portfolios. Regards, -- Niels.