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Re: multicast-transition
Tony Ballardie wrote:
> Marshall,
>
> > It seems to me that if you go to the trouble of having IGMP or PIM set up,
> then you
> > are likely to be multicast savvy, and so won't really need this.
> Otherwise, IGMP may
> > be set up (or not) by your provider - if they don't do multicasting, they
> are unlikely to
> > do IGMP. In fact, I know of at least one ISP that has PIM enabled
> backbones
> > but does not IGMP enable edge routers just to keep multicasting under
> tight control.
> > This all seems a lot different from the case of IPv6, where the provider
> may be
> > assumed to be cooperative. Having application level auto-tunneling would
> really
> > expand the usability of multicasting, I suspect a lot more than for
> network-layer tunnels.
>
> the idea, as I envisage it, is to have a special IGMP message
> anycast to a well-known (hard coded) anycast address, though
> probably changeable through a config option. Most OSs support
> IGMP, so the user would/can be oblivious, and similarly for
> intervening ISP(s).
>
> The other component to auto-tunnelling I forgot to mention is
> where a *router* has to get over non mcast infrastructure.
> My first suggestion for this was to alter the destn of PIM joins
> to the anycast addr, but I gather it affects other PIM behaviours.
> However, whether the trade-off of doing it anyway and altering
> PIM accordingly, is worth it?? My view is, that after all these years
> of not getting very far, we *need* transparent auto-tunnelling
> for the host AND router, else IP mcast will never fulfil its potential.
>
> As I see it that's not the end of the story either... then there's
> QoS, reliability (ok, dealt with by RMT, but still early days), and
> inter-provider pricing to solve before it can become commercially
> viable in itself. And I'm a fan of IP mcast, but these seem to be the
> harsh realities :-( The CDNs have overtaken IPM because their
> solutions plug the holes, although they tend to be less efficient
> in the network.
>
> Tony
Yes, except for one little thing - they are way too expensive to make a profit
from advertising. ALL unicast solutions for which I have pricing are
too expensive to make a profit from advertising. There is a LOT
of interest about multicasting in the (rather desperate) Internet
broadcast community. If we can get it together, the market will be there.
--
Marshall
T.M. Eubanks
Multicast Technologies, Inc
10301 Democracy Lane, Suite 410
Fairfax, Virginia 22030
Phone : 703-293-9624
Fax : 703-293-9609
e-mail : tme@on-the-i.com tme@multicasttech.com
http://www.on-the-i.com http://www.buzzwaves.com