When using Exchange server with Blackberry, companies have to set up BES server and configure it along with exchange server to work woth Blackberry devices.
Setting up Exchange server with ActiveSync, I believe there is no need to a separate server that handles the mobile devices,
If I am not wrong I saw a configuration of Android mobile device set up to work with Exchange Activesync, and all it was about is to enter email address and the password of a user in the mobile device and it will connect the device to exchange server.
I also believe the configuration of mobile devices is done in exchange Web App control panel .
I am talking about Exchange server 2010.
Please correct me if I am wrong.