[Olsr-users] Slow reaction to change in bitrate/signal changes

[Henning Rogge]

On Sat, Aug 18, 2018 at 8:02 AM Wolfgang Nagele <(spam-protected)> wrote:
>
> Hi,
>
> I've been testing a setup with two VMs. Both of them running two Layer
> 2 links (IPv6 only) to each other. Very straight forward. To simulate
> a link quickly dropping in quality I used the telnet Plugin to set the
> rx_bitrate and tx_bitrate parameters.
>
> I noticed however that this takes about 30 seconds to take effect and
> traffic switching to the other link. This is *much* longer than I
> would expect for OLSR to react to a link quality change. Are there
> config parameters that should be adjusted here? Changing the
> hello_interval down to 0.1 reduces this time to about 5 seconds -
> which is much better but still fairly slow.

Typically the ff_dat metric averages the frame loss estimation over 32
hello-intervals (which is a compile-time constant).

This is because the loss of a few hellos could both mean a bad link or
just bad luck.

In larger networks the TC interval also plays an important roll to
transport the link-metric change to the rest of the network.

Which means