The KeepAliveTime property indicates how often the TCP attempts to verify that an idle connection is still intact by sending ...

The KeepAliveTime property indicates how often the TCP attempts to verify that an idle connection is still intact by sending a Keep Alive Packet. A remote system that is reachable will acknowledge the keep alive transmission. Keep Alive packets are not sent by default. This feature may be enabled in a connection by an application. Default: 7,200,000 (two hours)