Service Advisory: Investigating Call2Teams Outbound Calling Issues

Update timeline

1. investigating Sep 25, 2026, 03:14 PM UTC

   We are currently investigating an issue affecting Call2Teams services across the EU and APAC regions. Users in the affected areas may experience issues when making outbound calls. Our teams are actively working to identify the root cause and implement a resolution as quickly as possible. Updates will be provided every 60 minutes as more information becomes available. We apologize for any inconvenience caused and appreciate your patience and understanding during this time. Dstny Support

2. investigating Sep 25, 2026, 04:01 PM UTC

   We have identified the root cause of the incident and have prepared an emergency fix. The hotfix is scheduled for deployment on 25/09/2026 between 8pm and 10pm UTC Time. We will provide an additional update following the deployment or sooner if necessary. Thank you for your continued patience and understanding as we work to resolve this matter. Dstny Support

3. monitoring Sep 25, 2026, 07:21 PM UTC

   Our Platform team has identified the root cause of the issue and implemented corrective measures to restore application services. We will continue to monitor service availability for the next 24 hours. and do not anticipate any further impact at this time. Thank you. Dstny Support.

4. resolved Sep 28, 2026, 09:24 AM UTC

   We are pleased to confirm that this incident has been fully resolved. Following the successful deployment of a hotfix, services have remained stable, and over the past 24 hours we have closely monitored the platform with no recurrence of the issue or further customer impact observed. We have identified the root cause of the incident and implemented corrective measures to prevent a similar occurrence in the future. To provide further transparency and insight into the incident, a detailed post-mortem report will be made available within the next five business days. We sincerely apologise for any inconvenience caused and thank you for your patience and understanding throughout this incident. Should you have any further questions or concerns, please do not hesitate to contact our support team. Thank you, Dstny Support

5. postmortem Oct 01, 2026, 02:30 PM UTC

   **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** * Restore and improve the access needed for configuration synchronisation testing, supporting earlier detection of similar issues. ### **Timeline** * 21 Sept 2026, 07:00 - Planned maintenance rollout begins; intermittent outbound call failures start. * 22 Sept 2026, 08:00 - A customer reports the issue. * 24 Sept 2026, 20:00 - Rollout completes; failures become more frequent. * 25 Sept 2026, 00:00 - Automated monitoring begins alerting on outbound call failures. * 25 Sept 2026, 10:00 - Further alerts received; engineering investigation intensifies. * 25 Sept 2026, 13:00 - Cause identified and a corrective change prepared. * 25 Sept 2026, 14:00 - Corrective change begins rolling out in the US. * 25 Sept 2026, 20:00 - Corrective change begins rolling out in the EU. * 25 Sept 2026, 21:00 - Outbound calling fully restored, with all services verified as stable.