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<p>To speak to the original question, I'd say bufferbloat<br>
</p>
<ul>
<li>is undesirable latency</li>
<li>was discovered when adding buffers counter-intuitively <i>slowed
</i>packet flow.</li>
</ul>
<p>That's so as to catch the reader's attention and immediately cast
light on the (memorable but mysterious) name.</p>
<p>--dave<br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 2021-04-05 11:24 a.m., David Lang
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:nycvar.QRO.7.76.6.2104050815220.18176@qynat-yncgbc">On
Mon, 5 Apr 2021, Stephen Hemminger wrote:
<br>
<br>
<blockquote type="cite">On Mon, 5 Apr 2021 08:46:15 -0400
<br>
Rich Brown <a class="moz-txt-link-rfc2396E" href="mailto:richb.hanover@gmail.com"><richb.hanover@gmail.com></a> wrote:
<br>
<br>
<blockquote type="cite">Dave Täht has put me up to revising the
current Bufferbloat article on Wikipedia
(<a class="moz-txt-link-freetext" href="https://en.wikipedia.org/wiki/Bufferbloat">https://en.wikipedia.org/wiki/Bufferbloat</a>)
<br>
<br>
Before I get into it, I want to ask real experts for some
guidance... Here goes:
<br>
<br>
1) What is *our* definition of Bufferbloat? (We invented the
term, so I think we get to define it.) <br>
a) Are we content with the definition from the bufferbloat.net
site, "Bufferbloat is the undesirable latency that comes from
a router or other network equipment buffering too much data."
(This suggests bufferbloat is latency, and could be measured
in seconds/msec.)
<br>
<br>
b) Or should we use something like Jim Gettys' definition from
the Dark Buffers article
(<a class="moz-txt-link-freetext" href="https://ieeexplore.ieee.org/document/5755608">https://ieeexplore.ieee.org/document/5755608</a>), "Bufferbloat
is the existence of excessively large (bloated) buffers in
systems, particularly network communication systems." (This
suggests bufferbloat is an unfortunate state of nature,
measured in units of "unhappiness" :-) <br>
c) Or some other definition?
<br>
<br>
2) All network equipment can be bloated. I have seen (but not
really followed) controversy regarding the amount of buffering
needed in the Data Center. Is it worth having the Wikipedia
article distinguish between Data Center equipment and
CPE/home/last mile equipment? Similarly, is the "bloat
condition" and its mitigation qualitatively different between
those applications? Finally, do any of us know how frequently
data centers/backbone ISPs experience buffer-induced
latencies? What's the magnitude of the impact?
<br>
<br>
3) The Wikipedia article mentions guidance that network gear
should accommodate buffering 250 msec of traffic(!) Is this a
real "rule of thumb" or just an often-repeated but
unscientific suggestion? Can someone give pointers to best
practices?
<br>
<br>
4) Meta question: Can anyone offer any advice on making a
wholesale change to a Wikipedia article? Before I offer a
fork-lift replacement I would a) solicit advice on the new
text from this list, and b) try to make contact with some of
the reviewers and editors who've been maintaining the page to
establish some bona fides and rapport...
<br>
<br>
Many thanks!
<br>
<br>
Rich
<br>
</blockquote>
<br>
I like to think of Bufferbloat as a combination of large buffers
and how algorithms react to those buffers.
<br>
</blockquote>
<br>
I think there are two things
<br>
<br>
1. what bufferbloat is
<br>
<br>
bufferbloat is the result of memory getting cheaper faster than
bandwidth increased, combined with throughput benchmarking that
drastically penalized end-to-end retries.
<br>
<br>
I think this definition is pretty academic and not something to
worry about using.
<br>
<br>
2. why it's a problem
<br>
<br>
the problems show up when the buffer represents too much time
worth of data to transmit (the time between when the last byte in
the buffer gets inserted into the buffer and when it gets
transmitted)
<br>
<br>
So in a high bandwidth environment (like a datacenter) you can use
much larger buffers than when you are on a low bandwidth line
<br>
<br>
David Lang<br>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
Bloat mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Bloat@lists.bufferbloat.net">Bloat@lists.bufferbloat.net</a>
<a class="moz-txt-link-freetext" href="https://lists.bufferbloat.net/listinfo/bloat">https://lists.bufferbloat.net/listinfo/bloat</a>
</pre>
</blockquote>
<pre class="moz-signature" cols="72">--
David Collier-Brown, | Always do right. This will gratify
System Programmer and Author | some people and astonish the rest
<a class="moz-txt-link-abbreviated" href="mailto:dave.collier-brown@indexexchange.com">dave.collier-brown@indexexchange.com</a> | -- Mark Twain</pre>
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