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SIM Provider Service Degradation RCA

Incident date: 2-3 June 2026

Summary

Multiple devices temporarily lost mobile data connectivity because of a service degradation at the SIM card provider. During the incident, affected devices appeared offline in Control Center, so configuration and monitoring for those devices were not available.

Device-side operation continued normally. Communication with traffic light controllers was not affected, and events were cached locally on the devices and delivered after connectivity was restored.

Impact

  • Multiple devices were shown as offline in Control Center.
  • Device configuration and monitoring were temporarily unavailable for affected devices.

No Impact

  • Affected devices continued to operate normally.
  • Communication with traffic light controllers was not impacted.
  • Events were cached locally and delivered after connectivity was restored.

Timeline

  • 2 June 2026, 05:15 CEST: Monitoring detected an unusual drop in connected devices.
  • 2 June 2026, 05:29 CEST: Investigation started.
  • 2 June 2026, 18:54 CEST: The SIM card provider opened a high-priority service incident.
  • 3 June 2026, 04:50 CEST: The SIM card provider resolved the service issue and device connectivity started to recover.
  • 3 June 2026, 05:27 CEST: Monitoring showed that the number of connected devices had returned to the previous level.

Root Cause

Affected devices could not maintain mobile data connectivity because of a service degradation at the SIM card provider. The detailed provider-side root cause is pending and will be reviewed once the SIM card provider publishes its RCA.

Resolution

The SIM card provider restored the affected service. Devices reconnected automatically as mobile data connectivity became available again. Locally cached events were delivered after the connection was restored.

Follow-Up Actions

  • Request and review the RCA from the SIM card provider.
  • Review whether provider-side service degradation can be detected and escalated earlier.
  • Review customer-facing communication for provider connectivity incidents.

Last updated: 3 June 2026, 05:27 CEST