S2s port number for unsecure and secure traffic

Does s2s communication, be it encrypted or plain text, always happen over port 5269?

How does the XMPP server know what communnication channel is secure and what is not, if it only listens on a single port.

For example, a Web server may listen on ports 80 (unsecure HTTP traffic) and 443 (secure HTTPS traffic). Thus, two ports are required to distinguish communication channels.

I’m new the XMPP server scenario.

regards,

Paddy.