Microsoft is currently experiencing a service disruption. This disruption is affecting users ability to sign into their Microsoft Teams physical phones (Yealink phones) and receive calls.

More info:

Users who are signed in can't make Microsoft Teams calls through SIP devices.

The impact is specific to a subset of users who utilize SIP devices in North America to access Microsoft Teams.

Affected services:
Session Initiation Protocol (SIP) devices

Status:
Microsoft Investigating