If you have Lync issues well then this trace can give you lot's of information for you.
Either if you log on Mediation Server, Edge server or the Front Ends server.
In Lync 2010 this was easy to figure out, but there has been a "small" hell to find out this in Lync 2013.
Anyway....here is the solution:
1. start the OCS logger for Lync 2013
2. Select what you can’t to log and to look at
3. Start your Logging
4. Stopp Logging and then press Analyse Log Files
5. Then press Analyze
6. Then SNOOPPER comes up like this and now it’s time for some magic
7. Press Tools and then Options
8. All this Options are blank and then mark them and Close
10. And voila……Here is your SIP Stack
Please enyou and happy sharing with this information :-)