[SR-Users] How can I setup Kamailio for failover on LCR ?

Hello, How can I setup Kamailio for failover on LCR ? Currently my Kamailio 4.x works with lcr but doesn’t care about gateway status. I mean that if a gateway match rule , it sends the call through without check if the gateway is available an never try the next one if the first fail. I’ve tried to implement inactivate_gw() But I received error that lcr_id_avp is not defined. I’ve added the parameters to lcr module for Ping and enable defunc but I’m unable to get it working. By the way I ‘ve trad that defunct is not a good practice as hacker sending malformed sip header can throw down the gateway. So what is the good and working way to setup outbound call failover ? Regards Sebastien