The logout utility sends a signal to the telnet session to
terminate. There can be at most one telnet session and one
console session. In case the telnet session is not up then
it signals : No active telnet session is present.
On telnet session, logouttelnet disconnects the telnet
session.
On the console, logouttelnet disconnects the telnet session.
On the rsh, logouttelnet disconnects the telnet session.