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

[Iñaki Baz Castillo]

2008/10/27 Dan Pascu <dan at ag-projects.com>:
> On Monday 27 October 2008, Iñaki Baz Castillo wrote:
>> 2008/10/27 Dan Pascu <dan at ag-projects.com>:
>> > I don't know about all internally generated replies, but I know that
>> > if a reply came from an end user device, it doesn't make much sense
>> > to pick an internally generated 408 Timeout on a dead branch.
>> >
>> > Maybe doing a custom selection, instead of the "lower reply code
>> > wins", would avoid the need to consider internal and external replies
>> > in a different way.
>>
>> That is why I suggested:
>>
>> - 2XX (inmediate)
>> - 6XX (except if disable_6xx_block == 1)
>
> I do not think that 6xx should be considered before 4xx or 3xx. 6xx means
> global response and if you get a 4xx and a 6xx at the same time, it is
> obvious that a device took a global decision that another device doesn't
> agree upon. 6xx should only be sent when a device knows _for sure_ that
> no other device can answer a call and it can give a final answer in the
> name of all devices (which is practically almost never when you have
> parallel forking).

If a 6xx is sent (for any reason) it should "win", so a 6xx should be
chosen over any other negative reply.
If both a 6XX and 4XX are received from two locations, 6XX must be the
winner, I don't understand why you say "no" here.
Well, 6xx are painful when are wrongly used, but for that we have an
option in TM module to treat a 6xx as a 4xx.




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