Rainbow - [EU] Rainbow Hub - Loss of Telephony service – Incident details

Post-Incident Report

Incident Window: June 1st, 2026 – 15:45 to 18:00 CEST

Summary

On June 1st, 2026, we experienced a network incident that led to Rainbow Hub service disruption in Europe, with up to ~50% traffic loss. During this period, some users may have experienced intermittent connectivity issues, up to full service disruption at peak impact.

Root Cause

The incident occurred in the context of our execution of the Rainbow Infrastructure upgrade plan and the connection of a new data center. An infrastructure-level network configuration inconsistency resulted in network instability and significant packet loss affecting Rainbow Hub components.

Resolution

Our teams identified the issue and worked in coordination with our infrastructure provider. The misconfigured routes were corrected and the network stabilized.
Packet loss was resolved by 17:20 CEST, with full service restoration completed at 18:00 CEST.

Preventive Actions

To prevent recurrence, we are implementing the following improvements:

• Strengthening configuration validation processes, including multi-level and cross-DC checks

• Adjusting change scheduling to reduce user impact while ensuring adequate monitoring

• Enhancing monitoring and alerting, particularly for routing anomalies, link flapping, and infrastructure changes

• The ongoing infrastructure upgrade plan will furthermore result in better platform resilience to network instabilities

Service restored
Service has now been restored. Our teams are continuing to monitor the situation closely to ensure ongoing stability.
If you continue to experience issues, please restart your Rainbow phone or softphone application.
Thank you for your patience and understanding throughout this incident.

Service restoration in progress
Services are currently being restored. Please note that it may take some time before full service is fully restored for all customers. Our teams remain fully engaged to complete the recovery as quickly as possible.

The network has been stabilized, but the service is still impacted. Our teams are now focusing on the application layer and are fully engaged in restoring full service as quickly as possible.

Our teams remain fully mobilized and are continuing in-depth analysis with our IaaS provider. Work is progressing, and we are focused on restoring full service stability.

Ongoing investigation
We are observing an intermittent network issue affecting both our data centers in Roubaix and Limburg. We are working closely with our IaaS provider to analyze the situation and identify the root cause. Our teams remain fully engaged to restore full stability as quickly as possible.

Increase in impact
We are currently seeing an increase in the number of customers affected. All European users are impacted. We understand how critical this service is and sincerely apologize for the continued inconvenience. At this time, the root cause has not yet been identified, but our teams are actively investigating and working urgently to resolve the issue.

We’re currently experiencing a loss of telephony for some customers, with intermittent disruptions affecting others. We understand the impact this may have and sincerely apologize for the inconvenience. Our teams are actively investigating and working to restore full service as quickly as possible.