[Olsr-dev] Thoughts about an ETX-FF-Metric plugin
Thu Jun 19 20:51:30 CEST 2008
On Thu, Jun 19, 2008 at 20:33, Markus Kittenberger
>> Maybe we can teach olsrd to send a "I'm switching off" packet before
>> it shuts down. This way the neighborhood has a chance to see the route
>> loss coming.
> a real packet special packet type, or just an hello with damn bad lq values
A Hello without any neighbours in it... something like "Hello, I don't
>> As long as the "clear information" timer is shorter than the "drop
>> route" timer this should be no problem.
> i wanted it the other way round,..
> do not use for routing fires earlier (30 seconds after the last packet or
> earlier (4x hello interval)) (it may also stop hello timeouts, and further
> changes to the lq istory)
> much later (5 minutes or later) the history is deleted
Hmm... would require some changes in the link_set, but should be possible.
> would be no problem if the device announces its reboot,.. (stopping all
> neighbours from doing any further hello timeouts, modifing the history
> without receiving packets)
there is a chance that the neighbours don't get the package.
> how long does an started olsr needs currently before he has routes, 30
Depends on the timing... you need at least two hello intervals until
you have a symmetric link to a neighbor.
After this it just depends how fast you get the TCs of the other nodes
(might take a little bit time with activated fisheye mode).
> ok fine (i did forget this), replace 95% with 80% and think over it
> but in fact its irrelevant that with 95% loss this link wouldn`t be used
> sometimes (when its lq is low enough)
the 10%/0.1 value can be chosen by the link metric plugin, so changing
this is no problem.
> what disturbs me ist that it will take substantially more time for an dead
> link to drop from ETX 1.0 to an e.g 4.0 (LQ 0.25 NLQ 1.0) (at >= 4 for
> example an alternative route would be used)
> than for an link with suddenly 85% loss, which can be nearly twice as fast
> (#), because NLQ will drop too, so with an LQ of 0.5 and nlq of 0.5 ETX 4.0
> is reached
Olsrd has a "quickstart" feature so that a link can get to a "good etx
value" fast... more a psychological thing. ;)
> # and maybe in relity more than twice as fast as it doesn`t have to wait on
> hello timeouts
"Wo kämen wir hin, wenn alle sagten, wo kämem wir hin, und niemand
ginge, um einmal zu schauen, wohin man käme, wenn man ginge." (Kurt
More information about the Olsr-dev