allow runtime configuration of keepalive timeout

kamailio/keepalive.cfg

@@ -12,6 +12,7 @@
 
 kazoo.keepalive_udp_only = KEEPALIVE_UDP_ONLY descr "should we send keepalive for udp only"
 kazoo.keepalive_nat_only = KEEPALIVE_NAT_ONLY descr "should we send keepalive for nat phones only"
+kazoo.keepalive_timeout = KEEPALIVE_TIMEOUT descr "timeout in ms for keepalive transaction"
 
 modparam("rtimer", "timer", "name=keepalive_timer;interval=1;mode=KEEPALIVE_S_TIMERS;")
 modparam("rtimer", "exec", "timer=keepalive_timer;route=KEEPALIVE_TIMER")
@@ -133,7 +134,7 @@ route[KEEPALIVE_PING]
 
    t_on_reply("KEEPALIVE_REPLY");
    t_on_failure("KEEPALIVE_FAULT");
-   t_set_fr(0, KEEPALIVE_TIMEOUT);
+   t_set_fr(0, $sel(cfg_get.kazoo.keepalive_timeout));
 
    t_relay();
 }