On Fri, Apr 29, 2011 at 4:40 PM, Tim Durack <tdurack@gmail.com> wrote:
Multicast is a great technical solution in search of a good business problem.
It's a useful replacement for broadcast on a local link. It's of limited utility elsewhere. On Fri, Apr 29, 2011 at 5:21 PM, George Bonser <gbonser@seven.com> wrote:
Multicast is perfect for a live event. Unicast is best for "on demand" viewing of something.
A layered cache implemented via unicast would work better and enable local fills for lost packets too. More, it sits to the side of the routers rather than in line, so it allows your routers to focus on what they do well: routing unicast packets. Some time ago I sketched out a notion for a layered opportunistic caching system that finds its nearest caches via anycast and validates the cached data via a very small signature stream from the original source. Even if your viewing is off-sync with others using the caches in your hierarchy the probability of bandwidth savings increases rapidly with the popularity of the content. The idea is that you deploy these caches as deep in your system as is cost effective. Regionally. The local CO. In the box with the neighborhood fiber terminal if you find the traffic savings beats the equipment cost. And of course such a cache system could work well for popular non-streamed content as well. Never quite linked up with someone interested in seeing an implementation though... Regards, Bill Herrin -- William D. Herrin ................ herrin@dirtside.com bill@herrin.us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004