**Date / time of Incident -** 18/01/2021 7:30 AM AEST
**Date / time of Restoration -** 18/01/2021 9:04 AM AEST
**Duration of Incident -** 1 Hour and 34 minutes
**Impact:**
A subset of Aatrox Communications SIP trunking services registered on a specific realm experienced intermittent registration and call drops.
**Root Cause and Resolution:**
A Sydney core Session Border Controller \(SBC\) realm was working as expected however, SIP traffic failed to route resulting in a loss of services for some trunks.
Registrations then failed over to a standby SBC to fully restore services.
**Actions to mitigate recurrence:**
An investigation is currently ongoing into the outage with our NOC team and upstream vendors on the root cause and mitigation actions. This PIR will be updated once the investigation has been completed.
