Exchange Reporter Plus' granular reports on the Skype for Business server allow you to:
Get information about all audio and video calls—failed or otherwise.
Identify users who make the most audio and video calls.
Check unassigned numbers and the routing rules assigned to those numbers.
View the configured voice policies and voice test configuration settings.
To access these reports:
Go to the Skype for Business tab.
Click the Audio/Video sub-category
These reports can be scheduled to be emailed to stakeholders at specified times. They can also be exported to destination folders in CSV, PDF, XLS, and HTML formats.