V_dyn_keepalive_period
if (V_dyn_fin_lifetime >= V_dyn_keepalive_period)
V_dyn_fin_lifetime = V_dyn_keepalive_period - 1;
V_dyn_rst_lifetime >= V_dyn_keepalive_period)
V_dyn_rst_lifetime = V_dyn_keepalive_period - 1;
V_dyn_keepalive_last + V_dyn_keepalive_period <= time_uptime) {
V_dyn_keepalive_period = 5;