<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<p dir="ltr">Hey Henning,<br>
Thanks for the confirmation. Would there be any disadvantage to just pushing the broadcast rate all the way to 11 (spinal tap style :))? Also, off the top of your head can you think of any other typical Mac or transport layer tuning that people do for high
throughput TCP? <br>
Cheers,<br>
Dan</p>
<div class="gmail_quote">On 18 Mar 2015 05:28, Henning Rogge <hrogge@gmail.com> wrote:<br type="attribution">
<blockquote class="quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><font size="2"><span style="font-size:10pt"></span></font>
<div>Yes,<br>
<br>
that is the reason... many mesh networks increase the basic multicast<br>
rate to 6 MBit/s to ignore the old 802.11b rates.<br>
<br>
Henning Rogge<br>
<br>
On Tue, Mar 17, 2015 at 11:06 PM, Dan O'Keeffe <d.okeeffe@imperial.ac.uk> wrote:<br>
> Hey again,<br>
> Actually it's ok, I figured it out. Because the OLSR HELLO messages are<br>
> broadcast at the 1Mbps data rate for 802.11, they experience a different<br>
> packet loss to the 11Mbps unicast traffic.<br>
> Cheers,<br>
> Dan<br>
> On 17/03/15 20:43, Dan O'Keeffe wrote:<br>
>> Hello,<br>
>> I'm trying to use the OLSR ETX extensions to determine the path quality<br>
>> to different destinations (so my application can send data to the<br>
>> destination with the best path as the quality changes over time).<br>
>> However the ETX values I'm seeing don't seem to correspond particularly<br>
>> well to the packet loss I observe when I manually ping the different<br>
>> destinations.<br>
>><br>
>> More specifically, I have a two node network with each node running<br>
>> olsrd and one node pinging the other (using a ping payload size of 0<br>
>> so that the actual ping is just a 28 byte header). At a certain distance<br>
>> the ping packet loss goes to 40%, but the ETX I observe using the<br>
>> txtinfo plugin is 1.000 (i.e. from the output of 'echo "/all" | nc<br>
>> localhost 2006).<br>
>><br>
>> Does anyone have an idea as to why I'm not seeing any packet loss<br>
>> affecting the ETX? Using tshark I can see the OLSR control<br>
>> messages being sent and received. However it's hard to tell whether<br>
>> any of the control messages are actually being dropped, and so<br>
>> I'm not sure whether the issue is that the OLSR control messages just<br>
>> aren't experiencing packet loss or I haven't configured the ETX<br>
>> calculation properly. From what I understand the ETX calculation should<br>
>> be based on the number of hello messages sucessfully sent and received<br>
>> over a sliding window, but perhaps there's more to the implementation?<br>
>><br>
>> The output of olsrd --version is:<br>
>><br>
>> *** olsr.org - 0.6.3-git_-hash_e334b612adcb7c22239a9dcafaf5b7ba - ***<br>
>> Build date: 2013-03-28 03:47:37 on marid<br>
>><br>
>><br>
>> I have made a few tweaks to the default config (see attached), but<br>
>> I don't see that they should make a difference.<br>
>><br>
>><br>
>> Finally, I should note that I'm running in an emulated environment<br>
>> (using the CORE EMANE wireless network emulator). The only way I could<br>
>> see that making a difference is that perhaps the same packet loss isn't<br>
>> being applied to broadcast traffic as to normal traffic, but before I<br>
>> check that on the CORE EMANE mailing list I'd just like to be sure there<br>
>> isn't an obvious issue with my olsrd configuration.<br>
>><br>
>> Thanks for any help!<br>
>> Dan<br>
>><br>
>><br>
>><br>
><br>
><br>
> --<br>
> Olsr-users mailing list<br>
> Olsr-users@lists.olsr.org<br>
> <a href="https://lists.olsr.org/mailman/listinfo/olsr-users">https://lists.olsr.org/mailman/listinfo/olsr-users</a><br>
</div>
</div>
</blockquote>
</div>
</body>
</html>