[Asterisk-Users] Can Asterisk pass through SIP status codes transparently?

[Tony Friar]

Hi,

I'm reasonably new to Asterisk and have a question which I hoping somebody can help me with. I've looked through the archives and config guides, etc but unfortunately I can find no mention of the information that I'm looking for.

I have an Asterisk server running version 1.07. On the user side there are several Grandstream phones and two 24 port fxs gateways. Asterisk is configured to send outgoing PSTN traffic to a SIP to ISDN PRI gateway. 

When an outgoing call is unsuccessful for any reason (busy, congestion, wrong number, etc) the SIP/ISDN gateway sends back a SIP status code to Asterisk. Asterisk then sends a status code of 486 (busy here) to the user devices irregardless of the SIP status code that it received from the SIP/ISDN gateway. I can chnage the code that Asterisk sends to 503 by modifying the macro outisbusy and setting outisbusy to send a congestion status code instead of a busy status code. However this 503 status message is then sent to the end user devices when the SIP/ISDN gateway sends back a 486 busy here status code.

Is there any way that Asterisk can be configured to pass on status codes unchanged or at least to group certain status codes received from the SIP/ISDN gateway into specific code that are sent to Asterisk?

Thanks.

Regards

Tony Friar