Hello,

 

I’ve setup two Kamailio machines, one which does all the processing and the second one which always replies with a 500 Server Internal Error, to test my Dispatcher fail-over.

When routing a call, the call is always routed to the second Kamailio first, to test the fail-over.

 

What happens in this scenario is the 500 is received by the main Kamailio and the 500 message is duplicated to the capture server. After this the failure_route kicks in and the 500 is obviously never sent back to the initiator.

The changes made to the 500 message  (adding a new header), in onreply_route, aren’t present when the message is duplicated to the capture server, because the original 500 message is duplicated instead of the modified one.