The IP over ATM Mailing List Archive by date

["Eric W. Gray" <gray@ctron.com>]

Andrew,

	I don't think you need to run out and get a "silly" hat - it seems to
me very likely that most switch implementations will consume many times the
resources required for a uni-directional pt-pt when using a pt-mpt.  Otherwise,
these same switches would not be able to distinguish a single-leaf pt-mpt from
a uni-directional pt-pt and could probably even support adding parties to either
one equally effectively.

--
Eric Gray

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Andrew wrote (in part):
> >>   Note that pt-mpt calls, even those with a single leaf, can be a lot more
> >>   expensive than pt-pt in some ATM switch implementations.
>
> Reality check here - are you _seriously_ suggesting people are going
> to be building MARS-based IP multicast over ATM solutions when their
> ATM switches are having trouble coping with a pt-mpt VC with a _single_
> leaf node!? C'mon Andrew, lets not optimize for silly cases.

It's not a case of "having trouble with a pt-mpt VC", it's just an economic
argument not to waste resources unnecessarily: I believe there will be a cost
differential between pt-pt and pt-mpt-with-a-single-leaf in many cases (do any
other switch vendors think this important? If not, I'll willingly wear the
"silly" hat and do a "silly walk" off into the corner). Against this we should
weigh the extra cost of some more words in a protocol spec and some more lines 
of code.