My informal testing with W2K Advanced Server Terminal Services shows the server uses about 10 MB of memory for each user session. With possibly 900 concurrent users that could equate to 9 GB of memory overhead. Windows 2003 Server may be more efficient in this regards and their may be configuration settings we missed, but this is something to think about.

If your application hasn't been designed with Terminal Services in mind, there are also application considerations as well. The SYS(3050) function should be used to limit foreground/background memory usage. Using SQL Server will probably reduce file handle usage, but if you are using local look-up tables or lots of cursors, you'll need the servers to be able to supply needed handles. In cases where drop-down lists are used (and don't change), I've come to believe that it is better to populate them from a table or cursor using AddItem() and AddListItem() and then close that table/cursor.

Color settings are a hidden bandwidth consumer. If color isn't important, they should be set to 256 colors on the server and in the shortcut to the server (or application) using the Options settings in the Remote Desktop Connection software on the client workstations (if you're using that method instead of IE, which I recommend).

John