[SR-Users] INVITE timers

[Andrei Pelinescu-Onciul]

On Mar 26, 2010 at 16:56, Alex Hermann <alex at speakup.nl> wrote:
> On Friday 26 March 2010, Klaus Darilion wrote:
> > Am 26.03.2010 16:42, schrieb Alex Hermann:
> > > In sr3.0 this timer will be restarted after
> > > additional provisional responses
> > 
> > http://sip-router.org/docbook/sip-router/branch/master/modules/tm/tm.html#r
> > estart_fr_on_each_reply
> 
> And exactly under that uri is mentioned: "If not set, the fr_inv_timer will be 
> restarted only for the first provisional replies and for increasing replies 
> greater or equal 180"
> 
> So it is impossible to stop the timer from resetting at all. But this is just 
> a minor issue, the others are more important.

The idea was to avoid restarts by retransmissions of the same reply
(e.g. phones that retransmits 180), but still allow an extension of the
branch lifetime if the phone sends another provisional reply, not seen before.
E.g. 180, 180, 180 will re-start the timer only for the first 180.
     180, 180, 181, 181, 182  will re-start the timer 3 timers: for the
     first 180, for the first 181 and for the first 182.
Note that K 1.5 and older had exactly the same behaviour (and same
default) in this case (the code is inherited from ancient ser versions.)

In all the cases (restart on or off) you can still limit the total
invite lifetime (see max_inv_lifetime).

Anyway it would be trivial to add another setting for restarting fr_inv only
once, if it's really needed.


Andrei