Hello there. It seems UE4 WebSocket library doesn’t support sending ping or receiving pong (RFC 6455 Section 5.5.2). The library I am talking about Engine/Source/Runtime/Online/WebSockets/Public/IWebSocket.h. It uses https://libwebsockets.org, and in libwebsocket it’s LWS_WRITE_PING. To stop the server from closing the connection, we have to send a blank text/binary frame instead of ping control frame. I don’t think this is a good idea. Also, the pong control frames received from the server are ignored, instead of handled by the user.