[94912] in North American Network Operators' Group
Re: death of the net predicted by deloitte -- film at 11
daemon@ATHENA.MIT.EDU (Hank Nussbacher)
Tue Feb 13 00:38:33 2007
Date: Tue, 13 Feb 2007 07:37:22 +0200 (IST)
From: Hank Nussbacher <hank@efes.iucc.ac.il>
To: Peter Beckman <beckman@purplecow.com>
Cc: nanog@merit.edu
In-Reply-To: <20070212142519.C5983@thermonuclear.org>
Errors-To: owner-nanog@merit.edu
On Mon, 12 Feb 2007, Peter Beckman wrote:
> NBC can now stream their shows to me as a .mp4 and I could grab them as
> fast as they could send it, rather than in realtime. They might offer the
> same stream at different data rates: 1mbps, 5mbps, 10mbps, 30mbps (for
> those of us lucky enough to have Verizon FIOS at home). The streams would
> simply repeat once they streamed all the files in a list.
That is what layered IPmc is. There is a base stream and on top of that
additional "layers" are interleaved and you pick up just what you need -
depending on your b/w. There are other facets to layered IPmc such as
staggered streams, whereby the same VOD is transmitted 10x an hour, at 6
minute intervals and using clever encoding you "tap" into the multicast
stream and within an average of 3 minutes your VOD starts playing - at the
level of quality based on your available b/w.
I've seen this in action as far back as 1998 and just don't quite grok why
it never took off.
-Hank
