Takeover delay in Heartbeat HA cluster

I have set up a heartbeat HA two node cluster. And both of server have same configuration of ha.cf #cat /etc/ha.cf logfile /var/log/ha-log autojoin none bcast eth1 warntime 20ms deadtime 40ms initdead 30 keepalive 5ms node server1.com node server2.com I set keepalive and deadtime in milliseconds hoping failover will take place in less than second or deadtime value. But expected behaviour is not met. With this configuration if I stop heartbeat in one server another server will take only after about 20 seconds(rough estimate by a stopwatch). I was wondering is what heartbeat can only do or am I missing something?