I have inbound faxing working over g.711 however I recently edited the SpanDSP.conf.xml file and added the following lines:

<param name="enable-t38" value="true"/>
<param name="enable-t38-request" value="true"/>

Now when I try the same inbound fax that was working before I see this error in the fs_cli

[NOTICE] sofia.c:8490 Hangup sofia/internal/5555555555@example.com [CS_EXECUTE] [INCOMPATIBLE_DESTINATION]

My goal was to have the inbound faxes try t.38 first and then fail back to g.711 ... but obviously that isn't working as expected.

Can anyone provide some guidance?