[sr-dev] More about locally generated 408

[Iñaki Baz Castillo]

2010/4/12 Juha Heinanen <jh at tutpro.com>:
> Henning Westerholt writes:
>
>  > hm, i'd opt to keep the 408 here. What about setting a flag if you
>  > received a provisional response in reply_route, and then check this
>  > in your failure_route when you process the 408? We do it this way,
>  > and did not found any problems so far. I think Juha also proposed
>  > something like this earlier.
>
> yes, that is what i proposed and have been using myself for years.  i
> don't see any need to make changes in tm for this.

Hi, I already explained in other thread that this is not accourate
enough. Example:
- branch 1 replies 180 followed by a 503 (it sets the flag(1XX_RECEIVED).
- branch 2 raises fr_timer timeout (no response at all from the server 2).

You inspect the chosen reply in failure route and get 408, and also
you inspect the flag(1XX_RECEIVED) and it's enabled, so you understand
(wrongly) that the 408 local timeout was generated after ringing, but
that's not true. And most probably you would prefer to choose the 503
(so 500) rather than the local generated 408 (due to fr_timer
expiration).