[asterisk-dev] Handling 482 Loop Detected responses

[Klaus Darilion]

Maybe this code in Asterisk was added to handle 482 responses created 
and received by the same Asterisk server, without considering the 
scenario where the 482 is generated by an external component?

regards
Klaus

Am 02.07.2010 22:24, schrieb Terry Wilson:
> I have noticed an issue where if we make an outbound SIP call which is responded to with a 482 Loop Detected, instead of failing the call and letting the dialplan handle the error, we instead set chan->call_forward to a Local channel at the callers context with the extension that they were dialing. I can't think of a reason why we would want to do this. It makes it impossible to handle the error in any meaningful way. It appears Asterisk has done this since r3662:
>
> $ svn log -r 3662
> ------------------------------------------------------------------------
> r3662 | markster | 2004-08-26 20:16:16 -0700 (Thu, 26 Aug 2004) | 2 lines
>
> When detecting a hairpin, redirect to the appropriate local extension (bug #1974)
>
>
> (bug #1974 doesn't seem to be related, btw)
>
> The code also has the note:
>                      /* \note SIP is incapable of performing a hairpin call, which
>                      is yet another failure of not having a layer 2 (again, YAY
>                       IETF for thinking ahead).  So we treat this as a call
>                       forward and hope we end up at the right place... */
>
> which is clearly incorrect as RFC 3261 talks about how to handle spiralin, but if a *loop* (not a spiral) is detected by the destination, it is an error condition and I think should be treated as such. It is always "fun" changing behavior that "has always been there" but in my opinion this is just clearly wrong behavior.  Opinions?
>
> Terry
>
>