All meetings require at least one Teams authenticated user to "start" the meeting.

Authenticated users are those that have presented the system with information proving who they are. The easiest ways to do this are by joining from an application or device that you have provided your NetID and password, for example:  the Teams client on a computer or mobile phone.  Another way is to use a Teams conferencing PIN as the Leader.

Examples of how people can join a meeting as an authenticated user:

• Joining the meeting from the Teams client from a desktop or laptop computer.
• Using an IP Phone logged in as an individual or role-based account.
• Joining the meeting from a common area phone. (Many departments have these in conference rooms.)
• Joining the meeting from the Teams app on a mobile device. Mobile devices that are supported include: iOS devices (iPhones and iPads), Android phones and Windows phones. Please note: Minimum operating system versions apply for installation of Teams.
• Joining the meeting from a telephone -- not using the Teams app -- into a meeting with a conference ID and authenticating using a Teams personal conferencing PIN. 
• Joining the meeting from the Teams Web App on a desktop or laptop computer and entering their campus NetID and password for authentication.

Examples of situations where you are not considered to be an authenticated user:

• Joining the meeting from a telephone -- not using the Teams app -- and NOT authenticating to the system with a PIN.
• Joining the meeting from the Teams Web App on a desktop or laptop computer and entering the meeting using the “Guest” button.
• Any outside caller without a Teams account on the campus system.

When setting up an online meeting, you can set an option to have unauthenticated callers (cell phones, land lines, other businesses and universities, etc.) join the meeting without the need to “Wait in the Lobby”. “Waiting in the Lobby” forces outside callers to wait until "admitted" by an authenticated user.

However, you still MUST have at least one Teams authenticated user in the meeting. If no authenticated user joins, the online meeting will not begin and other callers will be dropped from the meeting!