The setup is:

Carrier ip is CARRIER_IP

Public network Kamailio IP will be PUBLIC_IP

Private network Kamailio IP will be KAMAILIO_PRIVATE_IP

Private network Freeswitch IP is FREESWITCH_PRIVATE_IP

ACK

CARRIER_IP -> PUBLIC_IP->FREESWITCH_PRIVATE_IP

And freeswitch tries to actually send ACK back to PUBLIC_IP which he can't access.

Kamailio trace: http://pastebin.com/raw/1W1sXuUa

Freeswitch trace: http://pastebin.com/raw/KkZCwTTJ

request_route: http://pastebin.com/raw/Y17pXUGY

NATMANAGE route: http://pastebin.com/raw/0BpPDjN0
WITHINDLG route: http://pastebin.com/raw/5LpwSigF

I'm seeking help with that - what parameter I need to change/add to solve that?

Maybe it's a networking problem - but why then ACK reaches Freeswitch and all other requests flow OK?

Thanks in advance, Alex

--