On Mon, Jan 26, 2015 at 5:13 PM, Jonathon Exley
On a related note, I have been poking around in ns2
trying to see if I can simulate TCP flows over a UFB service to see the effect of
different BWP burst sizes.
I don't get the latter two acronyms.
However the diffserv model in ns2 doesn't drop
packets marked red, it only assigns a higher RED drop probability - not quite the
behaviour I was looking for.
I think my not understanding the first part of the question leads to
me not understanding this part.
Has anyone on the list played with ns2 or ns3 and
looked at modelling QoS stuff?
The release candidate ns2 code containing pie, codel, fq_codel, red
The release candiate ns3 code incorporating codel and fq_codel:
Both are nearly done and could use more testers.
I personally avoid ns2 (tcl. ugh.) for ns3 (python, yea!), and in
neither case will a ns2 or ns3 model give you results that even
remotely match the real (bufferbloated) world, unless you configure
your sim to match it. (there's a pretty good test in the ns3 codebase
How I think about "QoS" is pretty different, In terms of importance:
fixing the device driver queues with techniques like BQL, then fair
queueing, followed by aqm, fixing the actual device driver queues, and
then and only then attempting packet prioritization of any kind. By
just applying "QoS" you are trying to direct the end of the firehose
whilst holding onto it next to the fire-engine.
From: nznog-bounces(a)list.waikato.ac.nz [mailto:firstname.lastname@example.org] On
Behalf Of Ewen McNeill
Sent: Monday, 26 January 2015 8:47 a.m.
To: Dave Taht; NZNOG(a)list.waikato.ac.nz
Subject: Re: [nznog] bufferbloat talk at nznog friday
And any advice on defining such operator shaping/policing policies to make them less
likely to cause adverse behaviour (eg, being less sensitive to packet arrival time of the
"last packet of the burst arrived 1ms too soon, so we threw it away, have a nice
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