Point of Technical peturbance Multicast is much more efficient. The data does not flood to every router in New Zealand. Actual data, just like unicast, only routes to those branches of the network where there is actual demand at that instance in time. If there is no downstream client application (player) requesting the data feed, no data will be sent to that location. The only data held by routers is information about the identity of the upstream multicast source, if there is client request. If the demand was only in Wellington the multicast data would not leave Wellington. When someone joins in Auckland then the data would flow to Auckland and no-where-else... When the Auckland users ceases the session data transfer would be pruned back to Wellington while the multicast session continues. Regards Michael Sutton http://www.internetnz.co.nz/members/by-elections/030619byelection.html http://www.internetnz.co.nz/biographies/bio03-msutton.html -----Original Message----- From: Richard Naylor [mailto:richard.naylor(a)citylink.co.nz] Sent: Wednesday, July 09, 2003 10:40 To: Ewen McNeill; Hamish MacEwan Cc: nznog(a)list.waikato.ac.nz Subject: Re: [nznog] Multicast status in New Zealand Its just as the size of "live" viewer base gets smaller, and bandwidth higher, multicasting doesn't seem worth the effort. If I stream an event for say 10 viewers, why should the rest of the NZ net get it sent to them without asking for it. rich _______________________________________________ Nznog mailing list Nznog(a)list.waikato.ac.nz http://list.waikato.ac.nz/mailman/listinfo/nznog