Hi,

I was testing a configuration integrating the OCS R2 with the Nortel CS1K PBX.  During testing, I noticed from the OCS Front-end server, when I try to get information of the OCS R2 mediation server in the OCS Console, I am an error, "Retrieving Data Failed".  When I log directly onto the OCS R2 mediation server, the server is running and certificate information shows.  I found this post:  http://social.microsoft.com/Forums/en-US/communicationsserversetup/thread/69db6dd3-a6da-4aae-9cf5-19c63a7fe472 that recommends disabling the Windows Firewall.  So, I disabled the Windows Firewall service (as per the article) and now it appears to be working fine. 

This didn't seem to be the most secure way to run OCS so I did some investigating and found out:  "This occurs when OCS is installed while Windows firewall is off during the installation process. If you turn on the firewall after installtion, the error is expected. 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, if run locally, 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."

Lesson Learned:  Ensure that Windows Firewall is running before you begin the OCS R2 installation!