[asterisk-dev] Forwarding of SIP response codes

[Mikael Magnusson]

Deti Fliegl wrote:
> Hi,
> 
> it seems that SIP response codes are not forwarded thoroughly back to an 
> SIP-UA. This happens for example in a call setup like this:
> 
> SIP-Phone -> Asterisk -> SIP-Gateway
> 
> If the SIP gateway answers 404 asterisk converts this into 503 and sends 
> it to the calling SIP phone. The additional header 
> "X-Asterisk-HangupCause: Unallocated (unassigned) number" is nice but 
> does not help the SIP phone to display the correct hangup cause.
> Is there any way to just forward the original response code? Did I miss 
> something in the documentation to get this working?
> 
> Deti

Are you using Congestion to terminate the call? It always sends a 503 
SIP response. Try Hangup instead which should map the "Unallocated 
number" cause code to a 404 SIP response.

/Mikael