[OpenSER-Users] SIP response code in case of UAS internet down

Hi, all We are implementing a failure route upon t_relay() to UASs. This failure route is intended to a Caller who's destination UAS is not responding at all, till the request gets timed out, which can be arguably interpreted as UAS' internet is down. The purpose is to re-route incoming calls to any alternatives; i.e. cell pnone or other landline # when the remote user site lost netwrok connectivity. For the scenario above, t_check_status("408") would be the best for determining? Any other better methods or test functions in Openser? Greatly appreciate experienced' guidance. Thanks in advance. John Chahn Kim