All this talk of exafloods seems to ignore the basic economics of
IP networks. No ISP is going to allow subscribers to pull in 8gigs
per day of video stream. And no broadcaster is going to pay for the
bandwidth needed to pump out all those ATSC streams. And nobody is
going to stick IP multicast (and multicast peering) in the core just
to deal with video streams to people who leave their TV on all day
whether they are at home or not.
The floor is littered with the discarded husks of policies about what ISP's
are going to allow or disallow. "No servers", "no connection sharing",
"web browsing only," "no voip," etc. These typically last only as long as
the errant assumptions upon which they're based remain somewhat viable.
For example, when NAT gateways and Internet Connection Sharing became
widely available, trying to prohibit connection sharing went by the wayside.
8GB/day is less than a single megabit per second, and with ISP's selling
ultra high speed connections (we're now able to get 7 or 15Mbps), an ISP
might find it difficult to defend why they're selling a premium 15Mbps
service on which a user can't get 1/15th of that.
At best you will see IP multicast on a city-wide basis in a single
ISP's network. Also note that IP multicast only works for live broadcast
TV. In today's world there isn't much of that except for news.
Huh? Why does IP multicast only work for that?
Everything else is prerecorded and thus it COULD be transmitted at
any time. IP multicast does not help you when you have 1000 subscribers
all pulling in 1000 unique streams.
Yes, that's potentially a problem. That doesn't mean that multicast can
not be leveraged to handle prerecorded material, but it does suggest that
you could really use a TiVo-like device to make best use. A fundamental
change away from "live broadcast" and streaming out a show in 1:1 realtime,
to a model where everything is spooled onto the local TiVo, and then
watched at a user's convenience.
We don't have the capacity at the moment to really deal with 1000 subs all
pulling in 1000 unique streams, but the likelihood is that we're not going
to see that for some time - if ever.
What seems more likely is that we'll see an evolution of more specialized
offerings, possibly supplementing or even eventually replacing the tiered
channel package offerings of your typical cable company, since it's pretty
clear that a-la-carte channel selection isn't likely to happen soon.
That may allow some "less popular" channels to come into being. I happen
to like holding up SciFi as an example, because their current operations
are significantly different than originally conceived, and they're now
producing significant quantities of their own original material. It's
possible that we could see a much larger number of these sorts of ventures
(which would terrify legacy television networks even further).
The biggest challenge that I would expect from a network point of view is
the potential for vast amounts of decentralization. For example, there's
low-key stuff such as the "Star Trek: Hidden Frontier" series of fanfic-
based video projects. There are almost certainly enough fans out there
that you'd see a small surge in viewership if the material was more
readily accessible (read that as: automatically downloaded to your TiVo).
That could encourage others to do the same in more quantity. These are
all low-volume data sources, and yet taken as a whole, they could
represent a fairly difficult problem were everyone to be doing it. It is
not just tech geeks that are going to be able produce video, as the stuff
becomes more accessible (see: YouTube), we may see stuff like mini soap
operas, home & garden shows, local sporting events, local politics, etc.
I'm envisioning a scenario where we may find that there are a few tens of
thousands of PTA meetings each being uploaded routinely onto the home PC's
of whoever recorded the local meeting, and then made available to the
small number of interested parties who might then watch, where (0<N<20).
If that kind of thing happens, then we're going to find that there's a
large range of projects that have potential viewership landing anywhere
between this example and that of the specialty broadcast cable channels,
and the question that is relevant to network operators is whether there's
a way to guide this sort of thing towards models which are less harmful
to the network. I don't pretend to have the answers to this, but I do
feel reasonably certain that the success of YouTube is not a fluke, and
that we're going to see more, not less, of this sort of thing.
As far as I am concerned the killer application for IP multicast is
*NOT* video, it's market data feeds from NYSE, NASDAQ, CBOT, etc.
You can go compare the relative successes of Yahoo! Finance and YouTube.
While it might be nice to multicast that sort of data, it's a relative
trickle of data, and I'll bet that the majority of users have not only
not visited a market data site this week, but have actually never done
so.
... JG