Thanks for the info Alex!
But, I don’t seem to get that behavior. My sngrep graphical flow located here:
https://snag.gy/qMWfvk.jpg <https://snag.gy/qMWfvk.jpg> shows that Kamailio absorbs
that negative ACK and then does an INVITE to the media server, which is what I want it to
do (because I have a failure route defined) But, 200 OK from the media server is being
passed back to the UA and then the ACK from the UA is being sent to the SIP service versus
the media server, which doesn’t make any sense to me. I must be looking at this wrong.