[Users] failure route problem

[Klaus Darilion]

Hi Juha!


Juha Heinanen wrote:
> Klaus Darilion writes:
> 
>  > I wonder if there is any reason at all, why a failure route will be 
>  > executed in case of the caller cancels the call. Thus, another option 
>  > would be to remove execution of the failure route if the caller cancels 
>  > the call.
> 
> i don't like these kind of exceptions.  a failure route will be
> definition be called if failure response is received.  i have in my
> failure route test
> 
> 	if (t_check_status("487")) {
> 		return;
> 	};

This is also what I do at the moment.

> which makes 487 a no-op and i don't have experienced any problems with
> it.

imagine a parallel forked call: one phone is busy (486), the other phone 
is ringing.

If the caller cancels the call, the status is 486, thus 
t_check_status("487") won't match and you send a canceled call to the 
voicebox :-(

>  > If we still want to execute the failure route, having the call canceled 
>  > by the caller should be visible in a status variable, which is 
>  > explicitly set by the caller action, not by any reply code from the 
>  > clients. Imagine a broken client which sends 4xx instead of 487 for any 
>  > reason. If this is the last response, the failure route again won't work 
>  > if it checks for status 487.
> 
> coping with all kinds of broken clients in the proxy makes life very
> complicated.
> 
> whatever you decide to do make sure it is backwards compatible with
> current behavior, i.e., introduce a new module option or something.
> this is very dedicated stuff and i don't want to get into a position
> where i need to re-test my ser.cfg.

ACK. Maybe we could introduce a new function which allows to test if the 
called canceled the call.

regards
klaus