qmux VS qtalk-go

The connection multiplexing layer is based on qmux, a subset of SSH that I've written about previously. It was designed to optionally be swapped out with QUIC as needed. Either way, everything in qtalk happens over flow-controlled channels, which can be used like embedded TCP streams. Whatever you do with qtalk, you can also tunnel other connections and protocols on the same connection.

Unrelated to macdriver, I released a protocol called qmux with a post explaining why this (but really any) muxing protocol, including and especially QUIC, is such a great primitive for network programming. The project came with two implementations, Go and TypeScript, with more on the way. The post about it was the first explainer article I'd done in a while and people liked it. This was important because the idea behind it was really more valuable than the protocol itself, but regardless we still need implementations of it to exist. To show the idea in action, I built a 130 line version of Ngrok, which turned into a great post walking through how it works.

What qmux does is give us a subset of the SSH protocol to multiplex many connections over a single connection. It was the missing piece of my original Twisted prototype. You can read more about how there aren't a lot of these protocols (but perhaps with QUIC are also the future of the Internet) in my previous post.

If nothing else, I hope people use this story as inspiration to think about using multiplexing to design better, simpler application protocols. Even if for some reason QUIC isn't the future, you now have qmux!

I'm trying to get to a 1.0 for qtalk-go, so I'd like more people to use and review its code. I also haven't actually gotten around to putting in QUIC as a usable base layer, which I think should be in a 1.0 release. It's in the name, qtalk was started with QUIC in mind. Not only will QUIC improve performance, resolve head of line blocking, and eventually be native to browsers, but being UDP-based means that hole punching can be used to establish peer-to-peer qtalk connections. I'd like to one day be able to use qtalk directly between machines behind NAT.