Symptoms
Assume that you develop a Microsoft Unified Communications Managed (UCMA) API 3.0 Runtime-based application that is integrated with a Lync Server 2010 environment. The application sends tones by using the ToneController.Send method (tone, volume). In this situation, the volume parameter value is unexpectedly inverted to "100%-volume".
For example, if the volume parameter value is set to 70%, the ToneController API will invert the value to 30%. Additionally, if the values of the tones for the volume are too low, PSTN gateway may reject the tones.Resolution
To resolve this issue, install the following cumulative update:
2847888 Description of the cumulative update for Lync Server 2010, Unified Communications Managed API 3.0 Runtime: July 2013
More Information
For more information about the ToneController.Send method, go to the following Microsoft website: