Can you provide an example of using multicast vs. unicast?
On May 18, 2000, over two million Internet users flocked to watch the Victoria’s Secret Fashion Show. Several different versions of the video stream were available: a 56 kbps unicast stream, 100 kbps unicast stream, and two multicast streams at 300 kbps and 700 kbps. The vast majority of these viewers did not have multicast available to them. Even assuming that everyone was using the 56 kbps stream, that’s over 100 Gbps of data being streamed, or the equivalent of 10 OC-48 connections. This is a huge expense, especially for a 30 minute event. However, any number of users could have joined the multicast streams, and the maximum amount of bandwidth that Victoria’s Secret would have needed for the event would have been 1 Mbps. A single T1 connection would have served to reach the two million users, if multicast had been available to them, and it provided higher quality video.
