Microsoft recently updated the SLAs for Microsoft Teams Calling Plans, Phone System, and PSTN Audio Conferencing to 99.99% uptime. This change reflects Microsoft’s commitment and confidence to deliver reliable calling experiences in Teams.
With this SLA update, Microsoft Teams users will be able to make a PSTN call, dial into conference audio via the PSTN, or process calls with Call Queues or Auto Attendant 99.99% of the time.
If the uptime of these services fall below 99.99% in a given month, Microsoft calculates the total downtime and payout service credit based on length of incident (in minutes) multiplied by the number of users potentially impacted by the incident.
Source: Microsoft