Recently we started testing our product (which uses websockets in browsers that support the feature) on IE11. The product works perfectly fine on many versions of Chrome, Firefox, Safari, and IE10.
What happens is the following:
The connection is established and then about ~15 seconds later it disconnects. When debugging the websocket server code, it looks like there is a WebSocket PONG event being sent to the server (with a few bytes of data), which we do not reply to (and that sequence repeats a few times) and then the client sends the close packet, we send a close response (and the connection is closed).
What is the proper handling of this? Do we just send unattached PING requests to keep the client alive? Any documentation links would also be very helpful, as Googling "websocket ie11" doesn't yield anything useful.
When reading RFC6455, it seems there is not supposed to be a response to an unsolicited PONG...