[OpenSIPS-Users] Why the best response is 408 instead of 486 when parallel forking?

[Iñaki Baz Castillo]

2008/10/30 Bogdan-Andrei Iancu <bogdan at voice-system.ro>:

> 2) priorities in reply selection (parallel forking) - based on the list
> started by Iñaki:
>
> - 6XX (except if disable_6xx_block == 1)
> - 3XX
> - 401 / 407  (authentication)
> - 415 (Unsupported Media Type)
> - 420 (Bad Extension)
> - 484 (Address Incomplete)
> - 4XX
> - 408
> - 5XX
>
> 486,480 - should not have priority (according to RFC algorithm) as they do
> not provide additional information that may trigger resending the request.

480 is a bit confused since some phones use it for DND or call reject,
but it could be also the response from a proxy where the user belongs
but it's not registered.
But 486 is always a reply for the final user (it could be replied by
the proxy if the user has all him assigned concurrent lines in use,
but 486 always means "user busy"). 486 is also used as DND or call
reject in some phones but again is a final user response.

So I would suggest that 486 is preferred over 480 since it could be
more realistic (there is in fact a real user capable of receiving your
call but he can't do it just now).

Regards.


-- 
Iñaki Baz Castillo
<ibc at aliax.net>