You install September 2014 Cumulative Update 5.0.8308.815 for Microsoft Lync Server 2013. Before that, you did not install August 2014 Cumulative Update 5.0.8308.738. In this situation, the Centralized Logging Service Agent Service (RTCCLSAGT) cannot be started or cannot capture data.
Additionally, you receive the following event in the Event Viewer.
To resolve this issue, install the following cumulative update:
3003358 October 2014 Cumulative Update 5.0.8308.831 for Lync Server 2013 core components
This issue occurs because the Microsoft.Rtc.ClsAgent.IISLog folder is missing from the .Net global assembly cache after you install September 2014 Cumulative Update 5.0.8308.815 for Lync Server 2013. Therefore, the Centralized Logging Service Agent Service does not listen on designated ports.