<br><br><div class="gmail_quote">On Mon, Oct 31, 2011 at 4:02 PM, Giovanni Di Stasi <span dir="ltr"><<a href="mailto:giovanni.distasi@unina.it">giovanni.distasi@unina.it</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
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Il 30/09/2011 10:55, Markus Kittenberger ha scritto:
<div class="im"><blockquote type="cite">olsrd would drop all links if u take the interface
down and not changing its channel while it stays (logically) up
all the time.
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<div>ip link set down dev wlan0</div>
<div>iwconfig wlan0 channel x</div>
<div>ip link set up dev wlan0</div>
<div><br>
</div>
<div>maybe iwconfig does not work on an downed interface (depends
on the wlan driver), than swap order of line 2 and 3,.</div>
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I have done the following that seems to help a bit:<br>
<br>
iwconfig wlan0 channel X<br></div></blockquote><div>hmm dont you have different bssids on your channels? </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div text="#000000" bgcolor="#ffffff">
ifconfig wlan0 down<br>
ifconfig wlan0 up<br>
<br>
Do I need to put some delay after tearing down the interface?<br></div></blockquote><div>olsrd "usually" gets informed via netlink in "realtime"<br>but this ist not 100% reliable, (just approx 99.99999% (-;)</div>
<div><br></div><div>Markus</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div text="#000000" bgcolor="#ffffff"><br>
Following this topic, I have also tried to change the HELLO and TC
timers. I have cut them to half but the recovery time does not
change. What should I also change?<br>
I am thinking about changing the quality window length. Would that
help? Btw, why is that no longer configurable?<br></div></blockquote><div>(cause there is no window anymore, ..) </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
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<br>
Thanks for the other suggestions. For the moment I would like to go
ahead without changing the olsrd code or making a plugin (just an
analysis of the Olsrd behaviour as it is now when you change
channels).<br>
<br>
Best regards,<br>
Giovanni<div class="im"><br>
<br>
<blockquote type="cite">
<div>Markus<br>
<div><br>
</div>
<div>
<div class="gmail_quote">On Fri, Sep 30, 2011 at 10:49 AM,
Giovanni Di Stasi <span dir="ltr"><<a href="mailto:gdistasi@gmail.com" target="_blank">gdistasi@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204, 204, 204);padding-left:1ex"> Hi everyone,<br>
<br>
I would like to receive some advices regarding an
experiment we are currently performing aboud channel
assignment algorithms. The scenario is multi-radio.<br>
<br>
The channel assignment algorithm (centralized) triggers at
a certain point the change of channels of most of the
interfaces of nodes. It may happen that a neighbor which
was reachable through one interface, after the change,
becomes reachable through another interface [1]. The
experiment we are doing shows an interruption of
approximately one minute before the TCP connections we had
established are able to return to their full speed.<br>
This is due (I noticed that by taking a look at the Olsrd
logs) to the time Olsrd needs to drop the old route (on
the old interface) and use the new one (on the new
interface).<br>
We would like to speed up things a little bit. The first
attempt we think to do is to reduce the Hello and TC
Intervals. This would speed up the change but will imply
greater overhead. First results however show no
improvements.<br>
A different solution would be to discard all the links
departing from the interface of which we have changed
channel. If we change the channel of an interface, it
means that all the links departing from that interface are
(probably) no longer good, so it is good to drop them and
start using new links (possibly just after the first hello
packet is seen, so to regain rapidly connectivity). Do you
agree on this solution? If that's the case, how can I
tell to Olsrd to drop all the links from a certain
interface?<br>
<br>
Thanks a lot,<br>
Giovanni<br>
<br>
<br>
[1] suppose two nodes each with two interfaces, the one
set on channel 1 and the other on channel 2. After the
channel change the first node starts using channels 3 and
4 and the second channels 4 and 3.<br>
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</div><font color="#888888"><pre cols="1000">--
Giovanni Di Stasi, Ph.D. Student
Dipartimento di Informatica e Sistemistica
Universita' degli Studi di Napoli "Federico II"
Via Claudio, 21 - 80125 Napoli - Italy
Phone: <a href="tel:%2B39%20081%207683821" value="+390817683821" target="_blank">+39 081 7683821</a>
Cell: <a href="tel:%2B39%20333%206383732" value="+393336383732" target="_blank">+39 333 6383732</a>
E-mail: <a href="mailto:giovanni.distasi@unina.it" target="_blank">giovanni.distasi@unina.it</a>
Skype-ID: gdistasi
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