TLSSocket.setKeepAlive

Enable/disable keep-alive functionality, and optionally set the initial delay before the first keepalive probe is sent on an idle socket. Set initialDelay (in milliseconds) to set the delay between the last data packet received and the first keepalive probe. Setting 0 for initialDelay (the default) will leave the value unchanged from the default (or previous) setting. Only available for already connected sockets; returns false otherwise.

Enabling the keep-alive functionality sets the following socket options: SO_KEEPALIVE=1 TCP_KEEPIDLE=initialDelay/1000 TCP_KEEPCNT=10 TCP_KEEPINTVL=1