[Olsr-users] [Olsr-dev] Configuring TC redundancy parameter?

[Henning Rogge]

On 05/06/2013 09:19 PM, chris - wrote:
> Thanks very much for your reply. My thought is that using solely the MPR
> set may increase reliability in our particular routing scenario, however
> it would be too much work to test. It may make a good project, though.

There are two reasons why MPRs make networks unreliable with the current 
implementation.

The first one is that the ETX metric tends to go up and down on all 
links except the ones with no packet loss at all (see 
http://en.wikipedia.org/wiki/Bernoulli_trial). This means even a totally 
stable network will give you some fluctiations because you can only 
measure packet loss, not the loss-probability itself.

The second one is that the current MPR algorithm is a pure greedy 
algorithm, which doesn't care about the former MPR set. This means there 
are situations where it will constantly switch MPR settings because of 
metric fluctuations. Which will result in a more instable flooding of 
control traffic.

Henning Rogge
-- 
Diplom-Informatiker Henning Rogge , Fraunhofer-Institut für
Kommunikation, Informationsverarbeitung und Ergonomie FKIE
Kommunikationssysteme (KOM)
Fraunhofer Straße 20, 53343 Wachtberg, Germany
Telefon +49 228 9435-961,   Fax +49 228 9435 685
mailto:(spam-protected) http://www.fkie.fraunhofer.de

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