Keith; > ] and 500 gadgets do not make a technology adopted when it has no > ] business model folk can understand. > > one business model that might be understandable is: you should support > multicast if/when it saves you enough bandwidth (over the same content > being sent over separate unicast streams) to make it worth your cost. It means it saves nothing for receivers that they don't want to receive multicast stream. Then, senders are not motvated to send multicast stream. Also, the bandwidth saving is beneficial to ISPs that ISPs supporting multicast should charge less to its customers. It's not bad if ISPs are competitive and backbone bandwidth were expensive. Masataka Ohta