The utility is building a visual diagram of a call sip flow by a unique identificator of some call (call-id). Thus if a switch operator wants to investigate the signaling part of some particular call, he may find call-id in the details of "Customer's/Vendor's Call Records":

Then you may press "Yes" button to start the call extraction.

To navigate the Sip Log Viewer page, click on Sip Logs hyperlink

Or you may open Sip Logs Viewer page later using Tools & Debugs -> Sip Logs Viewer:

When the call is extracted (green bubble), press on call-id to see the diagram of an extracted sip call flow:

Consider the example of a call number to the number 12345678:

If you can't extract the call, most probably the sip.log file on the back end of the server has been rotated already or the call is too old for the extraction and due to the absence of the sip log, there is no possibility to extract a call trace.

Red bubble - means a sip log extraction failure.
Green bubble - means a sip log extraction success.
Yellow bubble - means that sip log extraction is in process.