said by Walter Dnes:Let's face it, unicast (separate connection and duplicated bandwidth for each viewer) does
NOT scale. Attempting a few million simultaneous streams overloads the central servers. Offloading this onto your ISP ends up overloading your ISP's servers. The answer is multicast. A stream is sent out once, but can be received by everybody who has selected it. There was an unsuccessful attempt to do this in IPV4 ("MBONE"). It "worked" but didn't take off.
With the current generation of broadband speeds and faster CPUs, multicast streaming should be a success.
Good point. That could replace broadcast scheduled TV. But it won't give the zealots what they want - every single show OnDemand whenever they want it instead of a system based on scheduled times.