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Microsoft Teams Support
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Upcoming Certificate Changes Impacting Direct Routing Users

Rebecca Valdivia's avatar
Rebecca Valdivia
Icon for Microsoft rankMicrosoft
Sep 11, 2023
On September 5, 2023, Microsoft performed a test where all Microsoft Session Initiation Protocol (SIP) endpoints were switched over to use the new certificate requirements previously announced.  The ...
Updated Nov 09, 2023
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mmaric's avatar
mmaric
Copper Contributor
Sep 26, 2023

interesting. Made a quick test against suggested test SIP frontend(http://sip.mspki.pstnhub.microsoft.com/) and I see MSFT represents itself now with the certificate chain:

 

that said it looks as apart from the Root CA change there is also an intermediate cert that signs MSFT end entity cert? "Microsoft Azure TLS Issuing CA 01"

 

If above is correct behavior from the MSFT SIP end, and not announced elsewhere, the change that is coming is very dangerous.