A few days ago, I was demanded to give a presentation about the SSH protocol, which I summarized as in below slide.
Refer to this link
SSH protocol has been one of the most fundamental infrastructures since 1990s, proving encrypted, secure remote control and other network services for millions of servers over unsecure network.
It’s basically consisted of five different protocols, which are RFC 4250 The SSH Protocol Assigned Numbers, RFC 4251 The SSH Protocol Architecture, RFC 4252 The SSH Authentication Protocol, RFC 4253 The SSH Transportation Protocol and RFC 4254 The SSH Connection Protocol.