[e2e] Is RED dead?

John Kristoff jtk at northwestern.edu
Mon Sep 19 09:58:50 PDT 2005

Intuitively I've felt RED was a reasonable and worthwhile AQM mechanism
for some time.  I've even witnessed some success in using it some time


as have others.  I've come to another situation where I could again
enable it, but for completely different reasons and for potentially
much loftier goals.

I've recently been told by a trusted and clueful colleague that RED
is a "compromised concept" and a "dead horse".  That surprised me a
bit and I've been trying to understand why.  I've been reading and
reviewing as much of the recent research and implementation reports
I can find.  It seems there has been a significant withering of
interest in RED since about 2001 so there seems to be some truth in
my friend's sentiments.

Though I'm not convinced it is completely compromised.  I realize the
problem of tuning RED parameters and I believe most implementations
have not embraced later enhancements to the basic algorithm.  So I am
looking for second opinions on the utility of RED generally and also
practically from the operators that I know frequent this list.   For
the former group, is RED (or something like it) no longer required
for the Internet, contrary to to RFC 2309?  For the operational people,
I know congestion may not be an operational problem for you, but for
those that might have congestion on tail circuits to customers or in
years past, were there other operational problems with enabling RED?


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