The workstation must be able to communicate with the server.
If the network connection between the client and the server is broken, the RunTime should detect it in about 5-10 minutes. When it does, it will start a 15-minute countdown and display a warning dialog box. The dialog box cannot be minimized or closed, but can be covered by other windows. Of course when the network connection is broken, any server-based files will be inaccessible.
The RunTime will continue to operate normally while it tries to reconnect to the server. If it reconnects before the 15-minute countdown runs out, the dialog box will close. If the client reconnects, it can take about another 2 minutes to detect that the server is again connected.
If the RunTime cannot reconnect, it will quit when the timer runs out. It may take up to a minute for the RunTime's window to close. Normal exit procedures will be executed, including the /EXIT procedure. The user count on the server will not be decremented until approximately the same time.
The easiest way to check this is to map a drive to a server drive, or use Network Neighborhood, to view (or refresh) the contents of a server drive.