On Fri, 29 Apr 2011, George Bonser wrote:
Exactly. If more people/networks took advantage of multicast, it would greatly reduce the bandwidth requirements, particularly for live events. If there were 50 people listening to a popular radio show or watching a
1) As a consumer network (enterprise, home) - that case is VERY rare. 50 people consuming it at your house? Or at the office consuming the same feed? (even at a 10k employee company, the rate of that is fairly low, particularly on the same leg of the network - I'd love to see some statistics that prove me wrong). The amount of work that goes into supporting and maintaining this is much higher than the return I'd get from it. Even assuming the upstreams supported it.
2) as a content provider, there's a lot of extra work involved to maintain this with my upstreams, and every mid-stream between me at the consumer networks. I require specialists in multicast (comparatively speaking unicast specialists are a dime a dozen) and I have to fight a lot of politics with the upstreams, and I -still- have to support the unicast models so the folks who can't consume multicast can see my content.
3) as an a midstream network provider I have almost no motivation to support this. Sure, my network usage would be reduced - but I (more or less simplified here, but) make my living on each bit of traffic I carry - if I offered a way for providers and consumers to reduce their traffic, that would reduce the amount they pay me. Win for them, lose for me.
the fact of the matter is that until multicast or it's like -doesn't- require massive end-to-end support (and frequently configuration to support each stream), there won't be heavy use of it. When I can turn up a multicast stream as easily as I can turn up a unicast stream, there is -still- a absolute lack of client-side software to recieve and playback the streams, and very limited support for broadcasting the streams.
...david (one time multicast specialist supporting a 200,000 seat 4 channel multicast infrastructure, so I'm fully aware of what magic is really involved in maintaining it across divergent networks that -WE- owned (or could exercise control of). before that streaming 40Gb/s (~200 channels of unicast video for general consumers + on demand streams)
-- david raistrick http://www.netmeister.org/news/learn2quote.html dr...@icantclick.org http://www.expita.com/nomime.html
