The value of the parameter (an integer) represents the number of seconds between keepalive packets. If this parameter is zero, no keepalive packets will be sent. Keepalive packets, if sent, allow the server to tell whether a client is still present and responding. Keepalives should, in general, not be needed if the socket being used has the SO_KEEPALIVE attribute set on it (see socket options). Basically you should only use this option if you strike difficulties. 300 600