You're quoting me from two posts up, but I also specifically called out full-duplex HTTP in that post. HTTP/1.1 does indeed support full duplex. However, most

You're quoting me from two posts up, but I also specifically called out full-duplex HTTP in that post. HTTP/1.1 does indeed support full duplex. However, most proxies don't. E.g. if you put nginx in front of your application server, you might lose the ability to do full duplex streaming right there. Or, if your client is behind a normal forward proxy, they might not be able to get full duplex. But, it can be pretty hard to figure out what's wrong. So, in practice I don't recommend relying on HTTP/1.1 full duplex. To be honest, I don't recommend HTTP/2 full duplex either, because HTTP/2 is just an optimization applying to individual network hops, and you still have the same proxy software in between screwing things up (and maybe even downgrading the request to HTTP/1.1 for the next hop). Personally I recommend using WebSocket when you expect full duplex. That way, all intervening proxy servers either know that you are expecting full duplex (because they recognize WebSocket), or connection setup will fail fast.