Re: multicast (was Re: Readiness for IPV6)

["Stephen Sprunk" <ssprunk () cisco com>]

Thus spake "David Sinn" <dsinn () microsoft com>
> There is also a "cart and horse" issue here:  Where is the pervasive
> content?

No, it's a "chicken and egg" problem :)

> Most content providers don't want multicast because it breaks their
> billing model.  They can't tell how many viewers they have at a given
> moment, what the average viewing time is, or any of the other things
> that unicast allows them to determine and more importantly bill their
> advertisers for.  There is no Nielsen's Ratings for multicast so that
> advertisers could get a feel for how many eyeballs they are going to
> hit.

That assumes there is no signaling.  Commercial content will be encrypted and
clients will have to get a key (possibly for free).  Key distribution can be
tracked and billed perfectly.  Even for cleartext content, clients should be
sending RTCP reports periodically.

I think a bigger issue is that multicast is only truly compelling for
high-bandwidth applications, and there's just not a critical mass of users with
enough bandwidth to justify deployment today.

Even worse, multicast is truly only suitable for live applications; on-demand
content can't be realistically mcasted, and users will not settle for "the movie
starts every 15 minutes" when they've been used to live VOD with unicast.  The
only saving grace may be things like TiVo, where an intelligent agent slurps up
live mcasts in hopes that the user may want to watch it "live" later.

S