Blackboard Collaborate Ultra -Join collaborate from your phone
If offered by your institution, you can use the telephony feature to communicate with other users.
Mobile device users, who are using the Blackboard Student or Blackboard Instructor app to connect to a session, can't use the teleconference dial-in simultaneously with the app audio for communication during the session.
Up to 25 attendees can call into a session from the phone. If the maximum number of dial-in attendees has been reached, nobody else can call in.
There is more than one way to call into a Collaborate session with dial-in available.
Source: Blackboard