Commit 9eb9fb44 authored by Leigh Stoller's avatar Leigh Stoller

Minor changes wrt link queues.

parent 7de8df4f
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Copyright (c) 2000-2002 University of Utah and the Flux Group.
Copyright (c) 2000-2003 University of Utah and the Flux Group.
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<center>
......@@ -829,27 +829,13 @@
<h3>Are there other traffic shapping parameters besides latency,
bandwidth, and packet loss rate?</h3>
<p>
Yes! However, access to those other parameters is slightly more
difficult since you cannot specify them in your NS file. First
off, you should log into <tt>users.emulab.net</tt> and read the
man page for
<a href='http://www.freebsd.org/cgi/man.cgi?manpath=FreeBSD+4.5-RELEASE'>
<tt>ipfw</tt></a>. Refer to the section on <tt>dummynet</tt>; ipfw
is the user interface for the <tt>Dummynet</tt> traffic shaper.
As noted in previous section above, you can alter the traffic
shapping parameters of any delayed link (one in which you have
specified a bandwidth, delay, or PLR that causes a delay node to
be inserted). However, you will need to log into the delay node
for the link you wish to modify and interact with <tt>ipfw</tt>
directly. The easiest approach would be to make a copy of
</tt>/etc/testbed/rc.delay</tt> and edit the pipe commands as
desired (or replace the pipe commands with "queue" commands). The
pipe commands are indexed by number; the mapping from pipe number
to virtual link is available via the web interface on the
Experiment Information page for your experiment. Be sure to leave
the rest of the contents of the file as is. Once you have your
changes made, simply execute the file using the <a href="#UTT-2">
sudo</a> command.
Yes! Please see the
<a href="tutorial/docwrapper.php3?docname=advanced.html">
advanced tutorial</a>. Note though, that these other parameters
can be specified for duplex links only (not lans), and that they
are not configurable with <tt>delay_config</tt>, but with a
different testbed utility call <tt>tevc</tt> (also described in
the advanced tutorial).
</p>
</ul>
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EMULAB-COPYRIGHT
Copyright (c) 2000-2002 University of Utah and the Flux Group.
Copyright (c) 2000-2003 University of Utah and the Flux Group.
All rights reserved.
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<center>
......@@ -81,19 +81,22 @@ example.
<p>
Each link is has an NS "Queue" object associated with it, which you
can modify to suit your needs. (<em>currently, there is a single queue
object per duplex link; you can cannot set the parameters
asymmetrically</em>). The following parameters can be changed, and are
defined in the NS manual (see Section 7.3):
can modify to suit your needs (<em>currently, there are two queue
objects per duplex link; one for each direction. You need to set the
parameters for both directions, which means you can set the parameters
asymmetrically if you want</em>). The following parameters can be
changed, and are defined in the NS manual (see Section 7.3). <b>Note,
only duplex links have queue objects, lans do not</b>.
<code><pre>
set queue0 [[$ns link $nodeA $nodeB] queue]
$queue0 set gentle_ 0
$queue0 set red_ 0
$queue0 set queue-in-bytes_ 0
$queue0 set limit_ 75
$queue0 set maxthresh_ 20
$queue0 set thresh_ 7
$queue0 set linterm_ 11
$queue0 set q_weight_ 0.004</code></pre>
$queue0 set limit_ 50
$queue0 set maxthresh_ 15
$queue0 set thresh_ 5
$queue0 set linterm_ 10
$queue0 set q_weight_ 0.002</code></pre>
</p>
<p>
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