Most of our servers are licensed for 2 concurrent remote desktop sessions. This is fine, so long as everyone does their administrative task and logs off, but some people accidentally close sessions (disconnect but remain logged in) instead.

I know that you can force someone off with the right Admin tools, but it's a bit ugly and may hurt productivity or maybe even the server(?). I was thinking that a nightly Nagios check of remote sessions available nagging people would help enforce build discipline on the subject. Can anyone recommend a service check that can monitor terminal service availability?