We conduct performance testing in our WebSockets web application. Since our application is used in Africa, we also need to test it at very slow connection speeds.
The Chrome network throttling feature is great for HTTP traffic (HTML, CSS, JS files, etc.), but it doesn't seem to throttle WebSocket traffic. It would be great if we could strangle in the same way.
If you are using Linux, look at traffic shaping with the tc command. You can also use it to slow down the connection. Doing this on a network network stack is better than on a server. You can also use random drops, etc. Using tc.