HOWEVER, most of the 24x7 media sites (CNN, etc.) are doing on-demand
video, rather than streaming a constant feed.
1) rights
2) unicast doesn't scale to the sort of audiences of radio/tv
broadcasts and if you try it becomes financially unviable too
(even with people attempting to fake multicast, e.g. Akamai)
One way to manage both is to use the VCR model
On the one
hand, content providers aren't offering 24x7 multicast feeds because there
isn't enough multicast access at the end-points.
We offer it regardless but there's not many can use it
Apart from 24x7 broadcast there isn't an obvious killer app.
And there's reasonable argument over making the intenet = tv
brandon
2) unicast doesn't scale to the sort of audiences of radio/tv
broadcasts and if you try it becomes financially unviable too
(even with people attempting to fake multicast, e.g. Akamai)
Yeap, which is why the multicast holds up well for 24x7 streaming. Unicast
sucks for it because of the infrastructure demand.
Internet radio exists as a good current candidate for multicasting, since
it isn't used in VCR mode.
And there's reasonable argument over making the intenet = tv
Who's to say it can't be both TV and VCR and magazine all at once.
> HOWEVER, most of the 24x7 media sites (CNN, etc.) are doing on-demand
> video, rather than streaming a constant feed.
Just wait a year or two. There are now two companies that I know of (probably others) that do near-on-demand video via multicast:
http://www.digitalfountain.com/
By doing clever encoding techniques these companies are able to provide near on demand video streams via a *single* multicast stream. See:
http://www.digitalfountain.com/technology/DF_techOverview.pdf - simple overview
http://www.digitalfountain.com/technology/DFTechWhitePaper2.9.pdf - detailed geek overview
-Hank