[Olsr-users] low signal and dropping default route

[Bhat, Ishwara]

Hi,

Now that link quality is being discussed, please tell more on the link quality fields of topology set.

In the console we have topology set which lists LQ, ILQ, ETX and UP. Please explain these. I could not find this in the OLSR report.

Thanks,
Ishwar


-----Original Message-----
From: (spam-protected) [mailto:(spam-protected)] On Behalf Of Henning Rogge
Sent: Thursday, January 22, 2009 1:54 PM
To: (spam-protected)
Subject: Re: [Olsr-users] low signal and dropping default route

Am Thursday 22 January 2009 01:00:48 schrieb Derek C:
> Hi Aaron,
>
> Yes - I think you are right. I've been playing around with the nodes this
> evening (I've asked people not to unplug them) and signal is the problem
> (its a non-line-of-sight problem really). I'm going to fix it early next
> week.
>
> But this [default route dropping due to poor connection] has got me
> looking at olsrd.conf settings again. Do you know if there is good
> documentation on the OLSR "TcRedundancy", "MprCoverage" and "LinkQuality"
> directives?

The newest tip (development version of olsr) has a nice man page (thanks to 
Sven Ola who did most of the work to update the page !):

TcRedundancy 0|1|2:
This parameter controls the amount of information a node puts into it's 
(globally flooded) TC messages. Theoretically 0 should be enough for complete 
routing (and will produce smaller packages), but 1 and 2 add more redundant 
information.

MprCoverage 1 or higher:
This parameter controls how many nodes of your 1-hop neighborhood you choose 
to reach your 2-hop neighborhood with your TCs/HNAs/MIDs. Again, in theory 1 
should be enough, but because of link loss 2 might be a better choice to have 
more redundancy (which will cost airtime on the links). We hope we will have 
time to write a better MPR algorithm this year.

There is no "linkquality" directive, so I'm not sure which one you mean...

LinkQualityDijkstraLimit 0|255 [Pollrate]-120.0
This parameter is just a "cpu time reducer" by limiting the amount of dijkstra 
olsrd will run in a certain time. It should be used on devices with not enough 
CPU power.

LinkQualityFishEye 0|1
Fish eye (or "hazy linkstate protocol") is an algorithm that varries the 
"range" (time to live in hops) of your TC packages in a way that close 
neighbors (2/8 hops distance) will get more TCs than distant stations.
It can help to reduce the amount of TC traffic in a network OR increase the 
update frequency in your close neighborhood.

Henning


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