Port 22 is used for Secure Shell (SSH), which enables encrypted remote login and command execution on network devices.
* Port 23 = Telnet (unencrypted)
* Port 80 = HTTP
* Port 123 = NTP
From Andrew Ramdayal's guide:
"SSH uses port 22 to provide secure command-line access to devices such as switches and routers. Unlike Telnet (port 23), SSH encrypts session traffic, making it the preferred method for remote administration."