Microsoft enhanced a new 99.99% SLA for Teams Phone and Calling on December 1. The new SLA is backed with financial commitments for credit if Microsoft doesn’t meet its standards. All of this is very nice, as long as you understand how the SLA is calculated and what you need to do if problems happen to be in a position to make a claim.
https://office365itpros.com/2021/12/06/sla-teams-phone/
