[Cerowrt-devel] Anything but "AQM"
dpreed at reed.com
dpreed at reed.com
Fri Dec 20 16:22:30 EST 2013
Given that there is no likelihood of making localized queue management "intelligent" because it has no global information whatsoever, I strongly suggest that "smart" "intelligent" and even "active" are hugely misleading.
They are based on a completely false premise - that queues should be allowed to build at all, and that local information can solve highly transient global problems.
"Dumb Queue Management" is going to be far superior. Keep the queue at zero length, and try to be fair.
There's a simple way to do the latter - use a filter (similar to a Bloom filter) that captures recent/frequent users of the queue, and when the queue on an outbound link grows more than about 2-3 packets (double buffering is all you need to keep the link full) discard the most recent and frequent packets (or send information that tells them to slow down).
There's been a lot of wasted time and effort trying to build queues long enough so that you can be "intelligent", but by then you have already lost the battle. You've gotten into a positive feedback loop where you have encouraged the endpoints to send more packets than you can ever drain out of the queue.
I truly, truly do not understand why people don't look at realistic network loads and structures.
On Friday, December 20, 2013 3:52pm, "Rich Brown" <richb.hanover at gmail.com> said:
> You wrote:
> > What's in a name? AQM has been pretty thoroughly defined to equal
> > active queue *length* management and not packet scheduling.
> > Overloading "AQM" what cerowrt does is apt to cause even more
> > confusion in the field than it already does. We discussed using LBO as
> > a word but that appears hopelessly overloaded with leveraged buy out.
> > I go back to one I liked a while back:
> > Smart Queue Management. (SQM)
> > This got dissed on the aqm list too, but so far a viable alternative
> > TLA has not appeared. It's sufficiently different to hang a different
> > definition off of ("Smart queue management is an intelligent
> > combination of better packet scheduling (flow queuing) techniques
> > along with with active queue length management (aqm)”)
> > Any ideas for a name for packet scheduling, prioritization, and active
> > queue management better than just "AQM", or "QoS"?
> > SQM "Smarter Queue Management"
> > CeroShaper
> > LBO Latency and Bandwidth Optimisation
> I was prepared to agree with “SQM”, and had written a long note
> (below) when my brain uttered “Intelligent Queue Management”.
> I’m not convinced that one is better than the other…
> ===== The benefits of SQM ======
> Wikipedia sez… SQM may refer to:
> - Sociedad Química y Minera de Chile - a Chilean mining and chemical
> - Software quality management
> - Spectrum quality management
> - Supplier Quality Management
> - Sensors Quality Management Inc. - provides unbiased evaluations of a company's
> operations relating to issues of quality, service, cleanliness and value
> - Sky Quality Meter, a device for measuring light pollution
> and also : São Miguel do Araguaia airport IATA code
> sqm may refer to :
> - square metre
> - Windows Live Messenger log file extension
> So it doesn’t appear that there are any seriously conflicting uses of that
> And I prefer “Smart Queue Management” to “Smarter Queue
> Management”. We’ll leave to someone else to go out on the weak branch
> and espouse “Smarter queue management” and “Smartest queue
> management”. (What comes after that? “Smart and a half”,
> Cerowrt-devel mailing list
> Cerowrt-devel at lists.bufferbloat.net
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