My VoixeXML dialog does a consultation transfer (<transfer type="consultation"/>).
Everything works fine if the called party answers the call. When the destination is busy, I only
get error code 'unknown' but I would expect return code 'busy'.
Speech Server reports event "...Microsoft.SpeechServer.TelephonyException: A SIP request has failed, but no response code was received. The current operation is 'Opening'. The session state is 'Disconnected'. The remote participant
is 'sip:160@192.168.130.40:5060..."
But my SIP logs tell me that out dialogic media gateway sent back the correct SIP response "SIP:Response: SIP/2.0 486 Busy Here".
How can I find out why the transfer failed?