Symptoms
When you try to set up media in Microsoft Skype for Business 2016, the setup may fail and all media diagnostics information is missing when you examine the ms-client-diagnostics header in the Session Initiation Protocol (SIP) BYE message in the client log.
This issue occurs when you make a PC-to-PC call in Skype for Business 2016 from an external network.
Resolution
To fix this issue, install the December 8, 2015 security update (KB3114372) for Skype for Business 2016.
