#KeepAlive
setsockopt($sck,SOL_SOCKET, SO_KEEPALIVE, pack("l", 1));
#After 30 secs idle send KeepAlive probe
setsockopt($sck,IPPROTO_TCP,TCP_KEEPIDLE, pack("l", 30));
#Rest probes after 30 secs.
setsockopt($sck,IPPROTO_TCP,TCP_KEEPINTVL,pack("l", 30));