If you install the Edge server in non US Language setting you can run in to trouble, especially if the Language setting doesn't use “.” (dot) and is using “,” comma instead for delimiter in numbers.
There is a lot of blogs about this, but there is still people running in to this problem, and spending lot of time finding a solution for this.
- Users would see a ‘limited calling’ error in Communicator
- Mediation server would complain there was no valid A/V Authentication service
- front-end A/V Validation would simply fail
This bug has been reported to Microsoft, and is in the process of being fixed. In the meantime, you can work around this issue in the following manner;
- On the Edge server, add the Edge Service account to local administrators and logoff.
- Logon using the Edge Service account
- Go to control panel, Regional and Language options.
- Change the format to English (US).
- Remove the Service Account from the local administrators and reboot.
Source for this information: http://unified-communications.blogspot.com/2009/01/ocs-2007-r2-and-localization.html