[Olsr-dev] Thoughts about an ETX-FF-Metric plugin

Henning Rogge (spam-protected)
Thu Jun 19 12:36:05 CEST 2008

Am Donnerstag 19 Juni 2008 10:55:18 schrieb Markus Kittenberger:
> But how is the detection of lost packets, now?
> When do you count how much packets as lost, when not receiving any packets?
Each hello-timeout is counted as a sequence number addition and a lost 

> > The linkquality value is calculated by
> >LQ = sum (received[1..7]) / ( sum (received[1..7]) + sum (lost[1..7]) )
> this formula wonn`t react fast on dead links,.. )-;
> if not counting more than the lost hellos, a communicative link will neeed
> nearly full history duration to get an bad ETX if the link dies (gets
> totally disconnected)
Not completely (see above).

> The old approach gave each time slot the same weight, which was better for
> detection of dead links(as long as there are at least some packets per time
> slot)
> now it`s again based on the number of packets, which i dislike,..
the problem for small networks is that a timeslice contains not enough data to 
calculate a LQ value.

> but the history has still fixed duration, which is good (-;
I planned to set the length of the history to the hello-timeout value.


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