Subject: Re: the mbone experiment

From: [email-masked] (Tim Dorcey)
Date: Tue, 2 Sep 1997 08:40:05 -0700 (PDT)

At 4:42 PM 9/2/97, George Michaelson wrote:
>don't realize that the same glue which can run a broadcast event to thousands
>of people can mesh only two or three if you want. out 'there' off the network

But is this actually going to scale?  I mean to thousands of groups of 2 or
3?  Does it make sense to generate and maintain routing state for such a
small payback in bandwidth efficiency?  I can think of places where
bandwidth is indeed very precious, but it seems like that might be
addressed in a more focused way, rather than involving global routing
state.  We probably need a protocol layer on top of IP multicast that makes
this issue transparent, rather than writing applications that speak IP
multicast.

Tim

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From: Jon Crowcroft <[email-masked]>
Date: Tue, 02 Sep 1997 16:52:42 +0100

Tim
 
why do you think it HAS to be so much routing state?

if we were clever about aggregating small groups and RP assignment for
sparse mode, it could be very efficient indeed.....

the reduction in bandwidth of 2 or 3 times would surely be welcome on
international links if we are reasonably ingeneous about RP
placement...

surely the Internet busniess case is BUILT entirely out of bandwidth
reselling anyhow:-)....

cheers

 jon