**Date / time of Incident -** 04/12/2020 1:23 PM AEST
**Date / time of Restoration -** 04/12/2020 1:54 PM AEST
**Duration of Incident -** 31 minutes
**Impact:**
A subset of Aatrox Communications SIP trunking services experienced intermittent registration and call drops.
**Root Cause and Resolution:**
This Incident was caused by malicious SIP traffic hitting one of our public-facing SBCs, this then triggered the SBC to throttle bandwidth in processing the SIP signalling as part of our DDoS prevention mechanism.
A temporary fix was to block the offending IPs as well as tweaking some realm protection settings to alleviate the flow-on impact to customers.
**Actions to mitigate recurrence:**
An investigation of the issue indicates that the standard DDoS protections are working as expected. However, an investigation is ongoing to mitigate a specific configuration change. This is currently under review and close to implementation. This should help to resolve the issues seen during the outage.
