Incident Summary
Between 07:00 UTC on 21st September and 21:00 UTC on 25th September 2026, customers using Dstny Call2Teams in all regions experienced intermittent failures when making outbound calls, with some attempts timing out during call set-up. The issue was first reported by a customer at 08:00 UTC on 22nd September and became more frequent once the maintenance rollout completed on 24th September. A corrective change was applied in stages once the cause was identified, and outbound calling was fully restored at 21:00 UTC on 25th September, with all services verified as stable.
Root Cause
A performance-related configuration change, introduced during planned maintenance on 21st September, proved incompatible with how Call2Teams handles outbound calls. An incorrect default setting applied the change more widely than intended, leaving some call-handling components without the security certificates needed to complete call set-up. Calls routed through those components timed out, while others connected normally, which is why the failures were intermittent. The incompatibility was not identified during pre-release testing.
Incident Resolution
Engineering teams disabled the affected performance feature and restarted the relevant services to apply the change. To limit disruption, the fix was deployed outside normal hours, starting with the US, followed by the EU and APAC. Outbound calling was restored at 21:00 UTC on 25th September, and subsequent checks confirmed stable operation across all regions.
Mitigative Actions