Interesting .. http://blogs.msdn.com/scottos/archive/2009/07/28/announcing-the-office-communications-server-remote-connectivity-analyzer.aspx
Following on the heels of success of the Exchange Remote Connectivity Analyzer (created by Shawn McGrath and Brad Hughes), Premal Gandhi (UC Support Escalation Engineer), Matthew Fresoli (Supportability Program Manager) and Jason Stine (Senior Lead Program Manager) have been busy designing and writing a complimentary tool: The Office Communications Server Remote Connectivity Analyzer.
The tool is available at https://www.TestOcsConnectivity.com