onreply_route[handle_nat] {

        $avp(traced_user) = "1";
        sip_trace();
       
        if ($rs==180) {
          if (isflagset(FLAG_180)){
                xlog("INFO:opensips: onreply_route: Dropping consecutive 180 resposne\n");
                drop();
          }
        setflag(FLAG_180);
        }
        route(relay2);
}

route[relay2] {

        if ($rs==100)
           drop();
        if ($rs==180) {
          if (isflagset(FLAG_180)){
                xlog("INFO:opensips: Flag is set \n");
                resetflag(FLAG_180);
          }
          else{
                xlog("INFO:opensips: Flag is not set \n");
             drop();
          }
          #setflag(FLAG_180);
        }
        xlog("INFO:opensips: Sending $rs resposne out \n");
}