Re: Netflix Is Eating Up More Of North America's Bandwidth Than Any Other Company

[Robert Bonomi <bonomi () mail r-bonomi com>]

> From nanog-bounces+bonomi=mail.r-bonomi.com () nanog org  Tue May 24 22:12:57 2011
> Date: Tue, 24 May 2011 23:12:41 -0400
> Subject: Re: Netflix Is Eating Up More Of North America's Bandwidth Than Any
>       Other Company
> From: Christopher Morrow <morrowc.lists () gmail com>
> To: nanog () nanog org
>
> On Tue, May 24, 2011 at 10:48 PM, Lou Katz <lou () metron com> wrote:
> > > > An "elegant" idea, done in by changing technology.   *sigh*
> >
> > As USENIX director I sponsored and sheparded this project, called 
> > "Stargate". We at least got bits into the blanking interval at WTBS in 
> > Altanta.
>
> So... would this have been feasible today? given the bandwidth required 
> to send a full feed these days, i suspect likely not, eh? (even if you 
> were able to do it on all 500+ channels in parallel)

On the financial side, it is trivial.

On the engineering side, _impossible_.  Modern satellite feeds of NTSC
(analog) TV signals use compressed digital representations of only the 
image portion of each 'field' of the video stream.  Sync and blanking 
signals are _not_ transmitted; rather they are re-generated locally 
when the satellite stream is converted back to an NTSC analog signal.
Thus, even if you were to inject data in the vertical interval, it 
would be stripped before satellite uplink, and not recoverable at the
receiving side.

It's been a *LONG* time since I dealt with the data bandwith available
in the vertical interval, but, as I recall, the "raw' capacity is on the
same order as a DS-0.  *but* you have to deduct overhead for framing,
FEC, etc, as well as multiple redundant transmissions of each data 'packet'.  

To pick a conservative number, say you get an effective throughput of
2k bytes/sec,  That is roughly 150mbyte/day. That _might_ suffice for
a text-only, 'Big-8' only, feed..

As I understand it, a current USENET 'full feed', including binaries, take
two dedicated 100mbit FDX fast ethernet links, and they are saturated _most_
of the day.  At that rate, A full day of TV vertical interval transmission
wuould handle under _ten_seconds_ worth of the inbound traffic.  You would
around =ten=thousand= analog TV channels to handle a contemporary 'full
feed'.