Core Tools

The core tools for managing and monitoring client computers can be found in the buttonbar and menubar on the server computer. The first five buttons in the buttonbar are for basic control of the student computers: After a separate configuration, you can boot selected clients, log out users on the selected client, restart selected clients, shutdown selected clients, and take control of a selected client, respectively.

The sixth button lets you broadcast the teacher's screen to all active clients, and the seventh button stops broadcasting. The eighth button lets you run a command on the students' computers, while the ninth button opens a dialog with an input field for free text, which is broadcast to all active clients when you press Send. The message appears on the client computer in a new window and stays there until the student clicks the Close button.

The 10th and 11th buttons lock and unlock the selected clients. The final button on the far right displays some information about the selected client system, such as the hostname and IP address, as well as information about the installed CPU and memory size.

Managing Client Computers

The menubar offers some additional functions for managing and monitoring computers in the lab. From the Labels menu on the teacher's computer, you can modify the client labels found in the teacher's program window. Hostnames and usernames can be shown and hidden here.

Clients | Broadcasts lets you directly influence the connected client systems via the server computer. For example, Monitor user pulls up the screen of the currently active student computer into a VNC window on your screen but without you controlling the client. Assist user, on the other hand, opens a TigerVNC window on the server that displays the active client's screen, but now the teacher's computer can take control of the student computer.

The Broadcast screen and Broadcast screen (windowed) options show the screen of the teacher's computer in a full-screen view or in a window on the selected client. You can also select multiple student computers here. In full-screen mode, the client computer's desktop disappears completely and is replaced by the teacher's screen. If you select the windowed option, the teacher's screen appears in a window, but the student's panel bar remains visible. When broadcasting screens, the teacher's screen should not have a higher screen resolution than the clients. Otherwise the teacher's screen content will appear cut off on the client computers and require scrolling to see the entire broadcast screen. The Stop broadcasts option lets you stop the transmission of the teacher's screen to the clients.

In the Clients | Execute menu, you will find different options for running commands on the selected student computers. Execute command opens an input line where you can enter a program file name or a URL. Epoptes then starts the corresponding program file on the client or calls the specified URL in the client's web browser.

This option does not work for console commands. Instead, you should select Open command line for programs that need to run in the terminal. You can use this option to open a terminal with user or root privileges on the teacher's computer or, alternatively, a terminal with root privileges on the students' computers. In the opened terminal, you then invoke the appropriate commands. Terminal commands executed on the teacher's computer are used, for example, to demonstrate the input of certain commands with parameters and their output when transmitting the teacher's screen to the student computers.

Execute | Send message allows the server computer to send more extensive text messages to the selected clients.

Clients | Restrictions lets the teacher turn audio on or off on the selected student computers. In addition, the teacher can lock the selected clients here if required (this can also be done from the buttonbar) to prevent students from creating keyboard and mouse input. Once locked, a closed padlock icon then appears on the client screen with a corresponding note (Figure 3). The same menu item unlocks the client computers again.

Figure 3: If required, individual clients can also be locked from the Epoptes server computer.

You can also create groups to organize clients by clicking on the green plus sign at the bottom of the left pane in the main program window. Then use the Add to group option from the Client menu to assign clients to the individual groups, which allows you to send group-specific messages and apply actions to individual groups.

Benchmark

Clients| Network Benchmark lets you specify how long you want the implemented network benchmark to test the available bandwidth. When the test is complete, Epoptes displays the result in a separate window, giving the overall result as well as the upload and download bandwidth for each individual machine (Figure 4).

Figure 4: Epoptes also displays the bandwidth used from the server to the individual clients if desired.