The scale of streaming video on the Internet.
owen at delong.com
Thu Dec 2 15:02:37 CST 2010
On Dec 2, 2010, at 12:48 PM, Jay Ashworth wrote:
> ----- Original Message -----
>> From: "Leo Bicknell" <bicknell at ufp.org>
>> That's an interesting number, but let's run back the other way.
>> Consider what happens if folks cut the cord, and watch Internet
>> only TV. I went and found some TV ratings:
>> Sunday Night Football at the top last week, with 7.1% of US homes
>> watching. That's over 23 times as many folks watching as the 0.3% in
>> our previous math! Ok, 23 times 150Gbps.
>> Yowzer. That's a lot of data. 345 10GE ports for a SINGLE TV show.
>> But that's 7.1% of homes, so scale up to 100% of homes and you get
>> 48Tb/sec, that's right 4830 simultaneous 10GE's if all of Comcast's
>> existing high speed subs dropped cable and watched the same shows over
>> the Internet.
>> I think we all know that streaming video is large. Putting the real
>> numbers to it shows the real engineering challenges on both sides,
>> generating and sinking the content, and why companies are fighting so
>> much over it.
> It also proves, though I doubt anyone important is listening, *why the
> network broadcast architecture is shaped the way it is*, and it implies,
> *to* anyone important who is listening, just how bad a fit that is for
> a point- or even multi-point server to viewers environment.
Yes and no... The existing system is a multi-point (transmission towers)
to viewers (multicast) environment. No reason that isn't feasible on the
internet as well.
> Oh: and all the extra servers and switches necessary to set that up?
For equivalent service (linear programming), no need. For VOD, turns
out to be basically identical anyway.
> *Way* more power than the equivalent transmitters and TV sets. Even if
> you add in the cable headends, I suspect.
Not if you allow for multicast.
> In other news: viewers will tolerate Buffering... to watch last night's
> daily show. They will *not* tolerate it while they're waiting to see if
> the winning hit in Game 7 is fair or foul -- which means that it will
> not be possible to replace that architecture until you can do it at
> technical parity... and that's not to mention the emergency communications
> uses of "real" broadcasting, which will become untenable if enough
> critical mass is drained off of said "real broadcasting" by other
> services which are only Good Enough.
Viewers already tolerate a fair amount of buffering for exactly that.
The bleepability delay and other technical requirements, the bouncing
of things off satellites, etc. all create delays in the current system.
If you keep the delay under 5s, most viewers won't actually know
As to the emergency broadcast system, yeah, that's going to lose.
However, the reality is that things are changing and people are tending
to move towards wanting VOD based services more than linear programming.
More information about the NANOG