If users are not logged in to their Roehampton account (and depending on the options you have set for the meeting – for more on options visit this page) they will be put into a Lobby when trying to access an online meeting or lecture.
This is the notification you will see during a session when someone is trying to enter the meeting:
If you open the Participants pane (click Participants button at the top) you will see the list of people in the lobby, and you can admit everyone at once or specific people:
For someone waiting, this is how the Lobby appears. It has controls for audio and video, as well as other settings:
If you click the X to remove them, this is the message they will receive: