If you plan to use Windows Firewall, we strongly recommend that you enable and configure it before you install and activate Office Communications Server 2007 R2. If Windows Firewall is running when Office Communications Server is installed, the activation process automatically adds the exceptions needed for Office Communications Server. Windows Firewall must be running before you start the Office Communications Server services during the deployment process because that is when Office Communications Server opens the required ports in the firewall. If Windows Firewall is not running when you start the Office Communications Server services, the required ports are not opened.

If Windows Firewall is not running when you install Office Communications Server, you must start Windows Firewall after installation and then run the activation procedure locally to add the necessary exceptions. Alternatively, you can add the necessary exceptions to Windows Firewall manually. To identify the exceptions, search the installation log for the text string firewall exceptions. For details, see Firewall Rules in the Windows Server 2008 product documentation at http://go.microsoft.com/fwlink/?LinkID=144611 or Managing Program, Port, and System Service Exceptions: Windows Firewall (WF) in the Windows Server 2003 product documentation at http://go.microsoft.com/fwlink/?LinkId=144621 .

The activation process does not automatically add exceptions needed for Office Communications Server on any Back-End Database Servers.