[Serusers] Backup route from SER to GW

Hi, How do I create a backup route using failure_route for sending the transaction to second GW it the main GW is not responding in time. I use this in my ser.cfg and also timers if course... route { ... log("Call to PSTN"); t_on_failure("1"); rewritehost("main GW"); t_relay(); break; }; failure_route[1] { log("<<<<<<<<<< Main SVI is busy or down! Trying secondary SVI! rewritehosport("second GW:5060"); append_branch(); t_relay(); break; } And I guess this is OK. But my GW try to send this to internal IP adresses (192.168.x.x) that SER feeds my GW with (I guess). Is it possible to "remove" this IP adresses so that just ip of sec. GW is sent in record_route and Via:? Any other solution how to solve this...? Thanks, Anders