Why does the X2go client start an ssh daemon?

Question

I've been using X2go client on a windows machine to connect to a linux server for several years. Now I want to understand it a little better. I notice that when I open the session manager, an sshd process starts. What role does this play?

Answer 1

X2Go uses SSH for its transport protocol. See here for a description of the product features: https://wiki.x2go.org/doku.php/doc:newtox2go

Basic features of X2Go [emphasis added; sorry, I can't figure out how to embed bullets in quotes]

• Graphical Remote Desktop that works well over both low bandwidth and
• high bandwidth connections The ability to disconnect and reconnect to a session, even from another client
• Support for sound
• Support for as many simultaneous users as the computer's resources will support (NX3 free edition limited you to 2.)
• Traffic is securely tunneled over SSH
• File Sharing from client to server
• Printer Sharing from client to server
• Easily select from multiple desktop environments (e.g., MATE, GNOME, KDE)
• Remote support possible via Desktop Sharing
• The ability to access single applications by specifying the name of the desired executable in the client configuration or selecting one of the pre-defined common applications

Note that some of these features, like file/printer sharing bidirectionally aren't possible for a client connection, so a sshd process is started so that the server can connect back to the client to support bidirectional processes.