The SIP Trace page is a log window which displays the SIP signaling. It becomes very important when analyzing the functionality of the phone and is very helpful on for trouble shooting support request.
Open the page and clear all content.
Perform the scenario which caused the unexpected behavior in a basic environment.
You can filter the displayed SIP messages in the WUI via the "advanced" → "Network" page in the "Debug" section - setting :"SIP Trace for REGISTER/SUBSCRIBE/NOTIFY".
You may enable the filter if the problem is not assumed to be related to Registration (REGISTER) or BLF Function (SUBSCRIBE and NOTIFY) but call issues.
Reload the page
Select and copy the content of the page and paste it into a plain text document (using Notepad or KWrite)