[Olsr-users] Problem with establishing robust relaying in OLSRD
Mon Oct 24 13:58:42 CEST 2011
Yes absolutely 100%.
The problem does not happen all the time. We thought it might be related
to infinite loops between two nodes updating one another, hence why we
though the fish-net algorithm.
On 10/24/2011 01:56 PM, Markus Kittenberger wrote:
> are u sure, your wireless interfaces are working (in adhoc mode)?
> On Mon, Oct 24, 2011 at 12:41 PM, Denia Bouhired
> <(spam-protected) <mailto:(spam-protected)>> wrote:
> Hello all,
> Basically we're trying to run olsrd in embedded devices to create
> dynamic mesh networks. We have however been facing problems with olsrd
> that we are finding difficult to understand, let alone fix.
> In a simple 3 node setting with nodes A B C, we tried to cause some
> relaying to happen from A to C through B.
> We have tried to do this both physically by moving nodes A and C
> out of
> sight of each other and also by introducing a link multiplyer in
> olsrd.conf between A and C. We tried both etx_ff and etx_fpm for this,
> with little improvement from both. Find attached the olsrd.conf
> file, we
> are using olsrd 0.6.3.
> In the case where we tried to break the link physically between A
> and C,
> by, say, having A and B fixed and C moving away from A but within
> LOS to
> C, such that:
> A< x >C
> What happens is that the link between A and B starts to degrade even
> though the two of them haven't moved and only C has. If C comes
> back to
> it's original position than the link between A and B is re-established
> In another instance, of what we think is the same problem, we
> manage to
> establish a 2-hop link between A and C by forcing a link multiplyer
> between A and C so for instance
> t1: A<--------------ETX=4------------->C #Only two nodes in the
> network, only one route exists
> t2: A<---ETX=1--->B<---ETX=1--->C #Node B inserted, olsrd chooses
> cost route through B, ETX=2
> The switch between routes was seemless as soon as node B is up in the
> network. This result has been repeatable for any number of power
> off and
> reboots of node B, the routing table can switch between direct and
> links without any problem. The problem has manifested itself when, for
> instance, node C is moved away, then, not only the links from A to
> B and
> B to C are lost (normal) but alarmingly the link between A and C also
> disappears from the topology and then it is impossible to re-establish
> communication between A and C unless olsrd is restarted. **Even though
> their state hasn't changed.**
> As you can see from the config file, we have enabled the fish-eye
> algorithm as we thought it might be a solution, but it hasn't made any
> difference as far as we can tell.
> This same problem has happend to us in various settings, but not
> consistently, so it has not been repeatable. I must also say that most
> times this had happened we had been trying to establish a VoIP link
> between A and C with B relaying the conversation.
> We are at loss as to what causes this problem and how to fix it, I
> my explanation has been detailed enough and that you'll be able to
> me some suggestions.
> Olsr-users mailing list
> (spam-protected) <mailto:(spam-protected)>
Dr Dénia Bouhired, Postdoctoral researcher
EPFL - École Polytechnique Fédéral de Lausanne
Laboratoire de Communications Mobiles
INR-139, Station 14
CH-1015 Lausanne, Switzerland
Tel.: +41 (0) 21 693 81 11
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