This handy bit of software advertises the following benefits:
http://www.devicelock.com/products/
The Problem
The environment was seeing SfB and Lync 2013 clients unable to make PSTN calls, forward to voice mail, operate from a VPN with any consistency, and multiple other instances of random badness.
Identifying the Cause
As it turns out, the organization had deployed a small number of laptops with the aforementioned DLP product, apparently in the default configuration.
The Fix
Using a laptop without the DLP software deployed resulted in zero issues. Ergo, this DeviceLock DLP product, in its’ default configuration, breaks SfB/Lync 2013 client software. If your organization wants to deploy this, ensure that the configuration is customized to leave SfB/Lync 2013 clients alone!
YMMV