While trying out the online Olypmics
coverage at www.nbcolympics.com I was intrigued to find that much of the
video content could be accessed only if you first verified that you were
US-based and served by one of a limited set of ISPs. As it turns
out, I am served at home by an ISP that was not on the list, and thus I
was not legally able to access much of the Olympics Web content, even though
others in my area served by a different ISP were able to access it.
ZDNet [1] has an article that sheds
a bit more light on what I assume is a related issue. Apparently,
although the content is accessed through traditional Web browsing, the
video streams themselves are not distributed to ISPs using the Internet
as we usually think of it. Rather it's being distributed through
a private backbone run by Limelight Networks [2]. From the article:
"When you download videos from
NBCOlympics.com, your computer isn’t actually going to the Internet to
get content. In fact, the content is usually no more than 2 router hops
away from your ISP. Limelight has partnered with over 800 broadband Internet
providers worldwide (such as Verizon, Comcast, Road Runner and Optimum
Online/Cablevision) so that the content is either co-located in the same
facility as your ISP’s main communications infrastructure, or it leases
a dedicated Optical Carrier line so that it actually appears as part of
your ISP’s internal network. In most cases, you’re never even leaving
your Tier 1 provider to get the video."
So, there's a second video Internet,
and you can only get to it if your ISP buys in. While we can get
into all sorts of political discussions regarding the appropriateness of
these sorts of things, there are also architectural implications for the
Web itself I think, so the TAG should be interested. First of all,
the main architectural principle, or at least the ideal goal of the Web,
is that all content be identified by URI and be accessible independent
of the location of or technology used by the client (I.e. presuming pertinent
standards are followed). That universal access is not available for
the Olympics streams. Secondly, if video is to become ubiquitous
on the Web, and if it really is the case that the public internet can't
handle the load (and I have no idea whether that's really true), then there
are important questions regarding the architecture and openness of the
Web.
My purpose here is not to endorse or to criticise the choices made by the
NBC Olympics folks, nor am I endorsing or criticising the products or services
offered by companies like Limelight. I do think it's worth keeping
an eye on Web architecture issues that arise when very high bandwidth video
is to be accessed by large numbers of Web users. BTW: kudos to Slashdot
[3] for pointing to all of this.
Noah
[1] http://blogs.zdnet.com/perlow/?p=9221
[2] http://www.limelightnetworks.com/
[3] http://tech.slashdot.org/tech/08/08/17/1855229.shtml
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Noah Mendelsohn
IBM Corporation
One Rogers Street
Cambridge, MA 02142
1-617-693-4036
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