SSH3: Faster and rich secure shell using HTTP/3

I was skeptical of the claim that it's faster than traditional SSH, but the README specifies that it is faster at establishing a connection, and that active connections are the same speed. That makes a lot of sense and seems like a reasonable claim to make.

Although, dollars-to-donuts my bet is that this tool/protocol is much faster than SSH over high-latency links, simply by virtue of using UDP. Not waiting for ack's before sending more data might be a significant boost for things like scp'ing large files from part of the world to the another.

Of course it has ACKs. There are protocols without ACKs but they are exotic and HTTP3 is not one of them.

He said not waiting for ACKs.

That makes even less sense, unless we are talking about XMODEM every protocol uses windowing to avoid getting stuck waiting for ACKs.

Of course you need to wait for ACKs at some point though, otherwise they would be useless. That's how we detect, and potentially recover from, broken links. They are a feature. And HTTP3 has that feature.

Is it better implemented than the various TCP algorithms we use underneath regular SSH? Perhaps. That remains to be seen. The use case of SSH (long lived connections with shorter lived channels) is vastly different from the short lived bursts of many connections that QUIC was intented for. My best guess is that it could go both ways, depending on the actual implementation. The devil is in the details, and there are many details here.

Should you find yourself limited by the default buffering of SSH (10+Gbit intercontinental links), that's called "long fat links" in network lingo, and is not what TCP was built for. Look at pages like this Linux Tuning for High Latency networks: https://fasterdata.es.net/host-tuning/linux/

There is also the HPN-SSH project which increases the buffers of SSH even more than what is standard. It is seldom needed anymore since both Linux and OpenSSH has improved, but can still be useful.