In a proactive move, Microsoft recently (March 5, 2024) conducted a 24-hour test of its infrastructure. The focus? Session Border Controllers (SBCs)– critical components that facilitate secure communication for Microsoft Teams calling, e.g. with Teams Direct Routing.
During this comprehensive test, Microsoft verified that SBC certificates meet stringent requirements. Specifically, these certificates must now include both Client and Server Authentication for their Extended Key Usage (EKU) extensions. This enhancement ensures robust security.
The final transition to this new certificate standard is scheduled for March 19, 2024. Organizations relying on SBCs should take note and ensure their certificates comply with the updated guidelines. By doing so, they’ll avoid any potential service degradation and maintain a secure communication environment.
Conclusion, opinion and summary
I would like to view the telemetry data and outcomes of the test. I suppose that many SBCs with a public trusted certificate for a Teams Direct Routing SBC meet the (new) requirement already.
If you are uncertain about your certificates’ compliance, you might inquire if users had any (PSTN calling) problems on March 5, 2024. And you can also examine your SBC’s certificate to see if it has the Extended Key Usage with Client and Server Authentication added.
For more details, refer to the article on Public trusted certificates for SBCs.
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