sing_websocket.control_frames.h0"></a>
        <span class="phrase"><a name="beast.using_websocket.control_frames.control_callback"></a></span><a class="link" href="control_frames.html#beast.using_websocket.control_frames.control_callback">Control Callback</a>
      </h5>
<p>
        Ping, pong, and close messages are control frames which may be sent at any
        time by either peer on an established WebSocket connection. They are sent
        using the functions <a class="link" href="../ref/boost__beast_