Bad interaction between sleep timeouts and Salut?

James Cameron quozl at
Wed Sep 15 23:26:02 EDT 2010

On Wed, Sep 15, 2010 at 08:04:25PM -0400, Martin Langhoff wrote:
> I am curious -- what is the frequency of "presence broadcasts" when
> Salut is used? Where is it set?

Three minutes.  Perhaps KEEPALIVE_TIMEOUT in

> With current 10.1.2 using salut over ad-hoc the neighbourhood view
> never stabilises, and it's very apparent that it's because nodes go to
> sleep too quickly (before they see others, before they are seen). And
> when awake, they take a long time to regain a good view of what's out
> there.
> If we can experiment with the timeouts (knowing where the knobs are)
> maybe we can find out...
> (Tomeu, I bother you because I suspect you'd know... hope it's not an
> annoyance...);a=blob;f=lib/gibber/gibber-r-multicast-causal-transport.c;h=3cdb2a8d3b88de473ee473da3af15e280d355c26;hb=HEAD

Salut over ad-hoc seems to use multicast packets, according to my
tcpdump, so this source file appears relevant.

The timers are specified there as constants, without configurable
settings.  So if you don't mind fiddling with them and recompiling, it
should be possible to improve the situation, at the expense of increased
wireless traffic.

Might also detect resume, evaluate time interval lost, and expire the
timer sooner.

James Cameron

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