Commit 32f29761 authored by Leigh B. Stoller's avatar Leigh B. Stoller

More verbiage, more cleanup.

parent 1e175c66
......@@ -37,24 +37,31 @@
To run linktest, select a Linktest test level from the dropdown on the
<a href="beginexp_html.php3">Begin an Experiment</a> page.
<ul>
<li>For fastest response, select <a href="#Level1">Level 1 - Connectivity and Latency</a>. This
will check that all nodes respond to ping and that latency is correct.
<li>For a more thorough but relatively fast test, select <a
href="#Level3">Level 3 - Loss</a>. Test levels are cumulative, so this option includes
Connectivity, Latency, Static Routing (if applicable) and Loss.
<li>If bandwidth is important in your experiment, select <a
href="#Level4">Level 4 - Bandwidth</a>. Be warned that the bandwidth
test takes up to 40 seconds per link. <b>Also note that not all
bandwidths can be accurately measured</b>. If this happens, a warning will
be placed in the log file for each link that is out of range for
bandwidth testing. It is up to you to ensure that links are behaving
as you expect them too!
<li> <a href="#Level1"><b>Level 1</b> - Connectivity and Latency</a>:
For fastest response, level 1. This will check that all nodes respond
to ping and that latency is correct.
<br>
<li> <a href="#Level3"><b>Level 3</b> - Link Loss</a>: Check link loss
characteristics. Test levels are cumulative, so this option also
includes connectivity, latency, and static routing (if
applicable).
<br>
<li> <a href="#Level4"><b>Level 4</b> - Bandwidth</a>: If bandwidth is
important in your experiment, select level 4. Be warned that the
bandwidth test takes up to 40 seconds per link. <b>Also note that
not all bandwidths can be accurately measured</b>. If this
happens, a warning will be placed in the log file for each link
that is out of range for bandwidth testing.
</ul>
<p>If you select a test lest level other than 0, Linktest
will run after the experiment completes its swapin. If a problem is
found, testbed-ops is automatically notified and a message will appear
in the activation log. Otherwise, no notification will appear.
<p>
If you select a test lest level other than zero, Linktest will run after
the experiment completes its swapin. If a problem is found,
testbed-ops is automatically notified and a message will appear in the
activation log. Otherwise, no notification will appear. A failure in
linktest will <em><b>not</b> cause the swapin to fail!</em> If traffic
shaping parameters are of critical importance to your experiments,
make sure you take a closer look if linktest reports failures!
</p>
<hr>
......@@ -72,7 +79,7 @@ in the activation log. Otherwise, no notification will appear.
<li> As with any automated testing procedure, we have to balance the desire
for accuracy with the possibility of false positives. To reduce
the number of false positives, we allow for a small amount of
fudge of any link. <b>If your results are dependent on total
fudge on any link. <b>If your results are dependent on total
accuracy, then you should test your links yourself!</b>
<li> When using linkdelays (endnodeshaping) latency is less accurate
......@@ -80,6 +87,12 @@ in the activation log. Otherwise, no notification will appear.
worst, latency can be off by up to 2ms, say for a roundtrip ping
packet.
<li> Linktest can take a <b>long time</b> on large experiments. Even
on very small experiments (5-10 nodes), doing the full bandwidth test
can 3-4 minutes. You should probably <em>not<em> do bandwidth
tests at swapin on any experiment over 20 nodes unless you are
prepared to wait a <em>long</em> time for the experiment to swap in.
</ul>
</center>
......
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