We have an 'iocConsole' script which ssh's to a common machine as a
common user (controlled by ssh public keys) and connects to a screen
session if it is active and otherwise starts a screen session. The
screen session multiplexes access to the single serial line. This
deals with most of your concerns, I believe.
1) We can control access without having to deal with IT
administrators (other than setting up the common user account to
begin with) -- just add a public key to the common user account. 2)
Multiple users can access a serial line session at the same time. 3)
Persistent scrollback, even if no users are currently attached.
