It provides fallback connection methods if WS connection fails, as it can do if you have, for example, a HTTP/1.0 only proxy between you and the client. For exa

It provides fallback connection methods if WS connection fails, as it can do if you have, for example, a HTTP/1.0 only proxy between you and the client. For example it was not that long ago that nginx did not support proxying HTTP/1.1. It is getting less and less relevant but at least for me the socket.io code has worked for a long time and there hasn't been a need to rewrite it.