WebSocket is a Web technology providing full-duplex communication channels over a single TCP connection. It enables an asynchronous communication from client to server. Unlike HTTP protocol where each client request is followed by a server response, WebSocket client and server can send single non-blocking messages without waiting for any answer from the other peer.
Since communication between client and server does not follow the request/response pattern, designing a scenario based on WebSocket technology is different than designing for plain HTTP protocol. There is no response linked to a request, therefore we have the following constraint, we cannot:
Some applications use a proprietary protocol over WebSocket that is compliant with the request/response matching pattern.