Hey Arseniy,

I had a similar thing so I tweaked the default config a little. Here is the kemi python bit I use.

        if KSR.rr.loose_route() > 0:
            if KSR.is_method_in("B"):
                # do accounting ...
                KSR.setflag(FLT_ACC)
                # ... even if the transaction fails
                KSR.setflag(FLT_ACCFAILED)
            elif KSR.is_NOTIFY():
                # Add Record-Route for in-dialog NOTIFY as per RFC 6665.
                KSR.rr.record_route()

            self.ksr_route_relay(msg)
        else:
            if KSR.is_ACK():
                if KSR.tm.t_check_trans() > 0:
                    # no loose-route, but stateful ACK
                    # must be an ACK after a 487
                    # or e.g. 404 from upstream server
                    self.ksr_route_relay(msg)
                else:
                    self.ksr_route_dispatch(msg) # Goes to my dispatcher logic
                return -255

            KSR.sl.sl_send_reply(404, "No request here")
        return -255

I use dispatcher to route between destinations and use double rr params as I sit behind NAT and have private endpoints I route to.

I also describe the rr params as well as depending on direction (to do NAT traversal.)

So from PBX to Customer - KSR.rr.record_route_preset("PUB_IP" + ";r2=on", "PRIV_IP" + ";r2=on")

And from Customer to PBX - KSR.rr.record_route_preset("PRIV_IP" + ";r2=on", "PUB_IP" + ";r2=on")

Hope this helps you get it working.

John.