There are several changes in Windows Server 2008 with regard to the way Terminal Services work in remote administration mode. Some are enhancements; at least one is a change for the worse. This post summarizes the most important changes.

Console session ID
In Windows Server 2003, when you logged in on the console, the session got the session ID 0. In Windows Server 2008 session 0 is no interactive session, anymore. It can only host services. Therefore, a console session is now essentially equal to remote sessions. This has several consequences for those who are working with Terminals Services in remote administration mode.

No /console switch
In WS03 you could connect remotely to the console session by using the console switch (mstsc /v:servername /console). This switch doesn’t have an effect if you remotely connect to WS08 server. The RDC (Remote Desktop Connection) client 6.0 still offers this option for connecting to a WS03 terminal server.

Session 0 viewer
In WS03 one has to use the console switch sometimes because some apps only work properly in a console session. WS08 provides a new feature for these legacy apps, the so-called Session 0 viewer. So, in theory, you should be able to work with these apps in a terminal session.

Maximum of two parallel sessions
In WS03, you can run three parallel terminal connections: Two terminal sessions and one console session. Since you can connect remotely to the console using the console switch, three administrators can work remotely at the same time. In WS08, the number of parallel remote connection is limited to two sessions.

Disconnect dialog
In WS03 you get the message “The terminal server has exceeded the maximum number of allowed connections” if you try to logon remotely on a server where two terminal sessions are already in use. WS08 displays a dialog whenever too many users are logged in, allowing you to disconnect the session of your choice. The user in this session will get a message giving her the choice to disconnect her session or to deny the request. If she doesn’t respond within 30 seconds her session is disconnected automatically. Since the session is not terminated she could continue where she stopped later.

“Restrict users to one session” is set by default
In WS03 and WS08, it is possible to restrict user accounts to one session. In WS08 this setting is turned on by default while in WS03 it is disabled. Many sysops use the “administrator” account to logon remotely to a server. If a second admin uses this account to logon, the first one is automatically disconnected without any warning in WS08. You can change this setting using the Terminal Services Configuration snap-in or thru Group Policy.

The fact that console and terminal sessions are more or less equal now is certainly an improvement. However, we have to see if this will really work with all legacy apps. There are still some differences, though. For example, it is not possible to connect to another terminal session if you work on the console.

It is certainly a disadvantage that in WS08 only two admins can work concurrently on a server. I really don’t understand why Microsoft is so stingy here. I was hoping that they would increase this number to at least five parallel sessions; instead they are even more restrictive now. This new disconnect dialog is definitely an enhancement, though. At least, you know now who is logged on and can ask him or her to let you go first.