The SIP Drops report tracks threats over a specified time period. See SIP calls dropped due to a multitude of typical problems:
- SIP parse errors
- Exceeding concurrent sessions thresholds
- SIP Invites dropped due to missing policy
- Registrations dropped due to missing policy
Ideally these reports come back with no entries, but in typical deployments a certain normal level can be expected. Use Thresholds to alert if normal levels are exceeded.