I was reading on web sockets 'Ping/Pong'. web-sockets used this messages as heartbeat. since socket-IO internally uses web-sockets, my question is this,
does socket-IO use same 'ping/pong' messages as heartbeat or there is some other mechanism for that?
if socket-IO uses ping/pong messages to check the connection, than what socket-IO uses for XHR connection and flash-sockets?
one more question, as we know, we can't send ping messages from client-side, does socket-IO provide any implementation for this?
Socket.io does ping/pong on all transports including polling, and this is done with its own heartbeat mechanism on engine.io which socket.io is dependent on. No ping/pong message of websocket is used at all.