When coupled with a good firewall the Secure Shell allows
you to configure your front end server in a highly secure manner but still
allows you access - e.g to download data files, check email etc
when you are off site.
Also,
because Secure Shell supports port forwarding, your secured server
can also provide for email and other services which are
only accessible via RSA strongly encrypted connections.
This document addresses Secure Shell version 2.x.