nanog mailing list archives

Re: Is anyone actually USING IP QoS?


From: Danny McPherson <danny () qwest net>
Date: Tue, 15 Jun 1999 12:27:34 -0600




Do i miss something 

perhaps :-)

Please.  Caching is _at least_ as efficient as multicasting (multicasting
_is_ caching, with zero retention time) - w/o associated security and
scalability problems.

Great, please do clue me in.  I wasn't aware that you'd corrected all the 
issues with caching, and somehow defied physics wrt the process of "duplicate 
bits" on a wire not actually utilizing b/w.

Presenting L2/L3 multicasting as the best or the only
or even a meaningful way to reduce transmission duplication is quite wrong.

I don't recall anyone doing that.  They're both good ideas, they both need 
work.

A primary concern is the absense (and most likely, impossibility) of any L2/L3
multicast routing scheme capable of supporting any significant number of 
mcast trees.

Oh, and caching has no problems?  I believe they're addressing two _slightly_ 
different problems.

Scalability on the Internet pretty much means that algorithms should run in
O(log(N)**M) where N is the total number of end-points and M is constant.
(Note that non-CIDR unicast routing doesn't fit this criterion, but CIDR does).

Perhaps O(log(N)**M) does apply to unicast, but the multicast model should 
differ.  I'd agree that in an ideal state, sure, looks good, but...

The benefits of mining cheap cheese on the Moon are quite obvious.  If you're
willing to overlook the small fact that the Moon isn't made from cheese.

I'm with Brett, never been to the moon..

_No_ technological advances can help the fact that L2/L3 multicasts cannot
be routed in a scalable fashion.  Think what happens when there is 1mil
multicast trees in the network.

and 10 billion caching servers won't give you even one extra bit to the 
end-user.

-danny





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