The 100 Gbit/s problem in your network

Tue Feb 12 13:51:31 UTC 2013

> On 02/11/2013 03:52 PM, Patrick W. Gilmore wrote:
> > One of us has a different dictionary than everyone else.
> 
> I'm not sure it's different dictionaries, I think you're talking past 
> each other.
> 
> Video on demand and broadcast are 2 totally different animals. For VOD, 
> multicast is not a good fit, clearly. But for broadcast, it has a lot of 
> potential. Most of the issues with people wanting to pause, rewind, etc. 
> are already handled by modern DVRs, even with live programming.
> 
> What I haven't seen yet in this discussion (and sorry if I've missed it) 
> is the fact that every evening every broadcast network sends out hour 
> after hour of what are essentially "live" broadcasts, in the sense that 
> they were not available "on demand" before they were aired "on TV" that 
> night. In addition to live broadcasts, this nightly programming is ideal 
> for multicast, especially since nowadays most of that programming is 
> viewed off the DVR at another time anyway. So filling up that DVR (or 
> even watching it live) could happen over multicast just as well as it 
> could happen over unicast.

Yes, but this basically assumes that we don't/won't see a change in 
their video distribution model, which is actually an unknown, rather 
than a given.

> But more importantly, what's missing from this conversation is that the 
> broadcast networks, the existing cable/satellite/etc. providers, and 
> everyone else who has a multi-billion dollar vested interest in the way 
> that the business is structured now would fight this tooth and nail. So 
> we can engineer all the awesome solutions we want, they are 
> overwhelmingly unlikely to actually happen.

If Big Content can figure out a way to extract money from the end
user without involving middlemen like cable and satellite providers,
then we'll see a shift.  There is no guarantee of an ongoing business
model just because that's the way it worked.  Look at what's happened 
to Blockbuster Video, which has gone from being a multi-billion 
dollar company to being well on its way to irrelevance.  What you're 
actually likely to see is a fight "tooth and nail" to ignore the 
signs of the coming storm, but that's not going to stop the storm, 
is it.  It will just open the door for more visionary businesses.

So, boiling everything down, the two Big Questions I see are:

1) Will throwing more bandwidth at the problem effectively allow the
   problem to be solved more easily than getting all the technical
   requirements (CPE, networks, etc.) for multicast to work?  I keep
   having this flashback to the early days of DSL and VoIP when I 
   would hear statements like "VoIP over the public Internet will 
   never work" over what are essentially that day's versions of these
   concerns.

2) Whether or not we'll have broadcast networks sufficiently large to
   make it worth the investment to solve the mcast hurdles, or if maybe
   their entire distribution model just undergoes a tectonic shift...
   which is hardly unprecedented, consider the sort of shift dialtone
   is experiencing w.r.t. Ma Bell's POTS plant.  In the meantime, the
   amount of non-broadcast video available as VOD continues to grow
   at a staggering pace.

The answer appears to be that multicast would be great if everything
were to remain as-is, but that seems a poor assumption.  We're still
in a period where multicast would be an awesome thing to have, but we
do not have it, and people are successfully moving away from the
"broadcast TV channel" model of video distribution, to a VOD model
where they can watch what they want, when they want, without being
limited to the 60 hours that their DVR happens to have queued up ("how
quaint" in this age of the mighty cloud!)

If you graph that all out, the picture you get shows a declining RoI
for multicast.  Any businessman would look at that and advise against
any significant investment in solving a problem that is already on a
path to self-resolution.

We know how to solve 1) by throwing bandwidth at it even if we cringe
at the requisite numbers today; throwing bandwidth at it is a brute
force solution that makes your C and J salespeople smile.  Products
like the AppleTV/iPad/etc have managed to make somewhat uncomfortable
marriages out of day-after-broadcast video and VOD(*).  We have
clever ideas about how to solve 1) with multicast, but no real world
implementations that actually work at any sort of scale, and that's
such a huge impediment to implementation when compared to just 
scaling known bandwidth and unicast delivery technologies...

We also have seen, from the advent of cable TV, that the availability
of new transmission opportunities leads to decreased viewership of
the OTA broadcast networks, and a growing pool of alternative video
to watch.

But now here's the killer.  The networks that could most benefit
from multicast, the existing TV networks, what's the incentive for
them to develop multicast technologies, something which I expect
that their distribution partners would see as a further unwelcome
jab at eventually cutting out the middleman?  I think it has been 
a hard enough sell for them to support buying shows (iTunes,
Amazon, whatever) but they're likely to get a lot of pushback from
existing dist partners as to why another broadcast technology
would be needed, when cable/satellite already have "solved" this 
problem and have a huge investment.

(*) I would note that legacy TV, with its requirement that you be
    available to watch it when broadcast, or have a device handy to
    spool it for later viewing, is an uncomfortable marriage of
    content and viewer.  FWIW.

... JG
-- 
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.