[Bloat] bloat, 3G networks and switch behavior

[Bloat] bloat, 3G networks and switch behavior

[Dave Taht]

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just stumbled across this old piece which links to some of the original
discussions around what has become called bufferbloat since, and also had
some links to papers I hadn't read.

http://blogs.broughturner.com/2009/10/is-att-wireless-data-congestion-selfinflicted.html

I'm curious as to who is monitoring 3G performance and latency to the
extent mentioned in this piece. Would love trendlines going back a couple
years....

this three parter was also pretty good:

http://www.netcordia.com/community/blogs/terrys_blog/archive/2011/09/29/application-analysis-using-tcp-retransmissions-part-1.aspx

The conclusion shows what happens when you start overrunning buffers in a
high speed switch.

http://www.netcordia.com/community/blogs/terrys_blog/archive/2011/11/02/rethinking-interface-error-reports.aspx

Money quote on that:

"So I went back to the network assessment tools that I used and found that
the interfaces that were reported by my tools all had much higher
percentage errors, but had very low data rates. The high-throughput
interfaces that I found in the CLI output had error percentages that kept
them from appearing in the top few pages of interfaces with high error
percentages. While it is important to identify the high-percentage error
interfaces (which also had low traffic volumes), it was the high volume
interfaces that were impacting the applications that communicated across
the network backbone.

The interfaces that I was investigating had very high traffic volume, had
hundreds of thousands of errors, and were key interfaces in the
infrastructure. Now I had a clear understanding of my misconception in
looking for interface errors. I had always thought that I should look for
high percent errors. But here were key infrastructure interfaces that were
exhibiting high errors, but because of the total volume transiting the
interfcaes, their percentage was low, relative to other, low-volume
interfaces. How should I handle this case?"

-- 
Dave Täht
SKYPE: davetaht
US Tel: 1-239-829-5608
FR Tel: 0638645374
http://www.bufferbloat.net

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