Because reservationless service is mostly automated, rates are far lower than operator-assisted conferencing. To address some of the problems of teleconferencing, most services offer features that can be used as necessary. In a meeting room, it is relatively easy to control the tempo and flow of conversation. However, control is more difficult to establish in a teleconference. These features give conference organizers the flexibility to manage a teleconference in much the same way they would face to face.
Roll call lets everyone know who is connected into the conference.
An operator conducts roll call, asking each participant for his or her name. Subconferencing allows designated participants to communicate privately within the call. The subconference attendees can later return to the main conference. In most cases, many subconferences can be established within any one call. Faxing allows a chairperson to distribute materials as they become relevant in a meeting.