From VoIP.ms Wiki
The Conference feature allows several people to dial into your DID number to be bridged together in the same conversation.
Conference provides the host with a dashboard monitor that allows organizers to monitor and control different aspects of the conference call in real time. Press the “Start Recording” button to get a recording of your conference call that you can listen and download after for any purposes.
Start using the Conference feature by clicking the “Add Conference” button to create a conference entry. Once your conference entry is ready you can route your DID number to it from the Manage DIDs > Edit interface to start receiving calls into your conference.
Name: This is the unique name of your conference. (e.g. Sales Meeting) Description: This can be used as a note or description to easily identify your conference. Maximum Participants: Specifies the maximum amount of callers that can participate in this conference. Leave empty for no limit. Once the limit is reached, the conference will be locked until a person leaves. Admin-level users are exempt from this limit and will still be able to access to join a locked conference. Language: Language for system messages, such as “Invalid Option”.
Name: This is the unique name of your Member Profile. Description: This can be used as a note or description to easily identify your Member Profile. PIN: Sets if the user must enter a PIN before joining the conference. The user will be prompted for the PIN. This also serves for selecting the member profile when the user joins the conference. Admin: Sets if the user is an Admin or not. Start Muted: Sets if the user should start out muted after entering the conference. Announce Join Leave: When enabled, this option prompts the user for his name while entering the conference. After the name is recorded, it will be played as the user enters and exits the conference. Announce User Count: Sets if the number of users in the conference should be announced to the caller as he joins. Announce Only User: Sets if the “only user” announcement should be played when a caller enters an empty conference.