The service allows you finding out who has called you, when the telephone line was busy, switched off or was outside the zone of coverage. By doing so, it ensures that an important call will not be missed.
Feature allows subscribers calling to a certain number in order to connect to a conference call. The one, who dials the number, will connect to the conference. However as a conference controller one should give that certain number to all the participants and set the time for conference in order for the participants to be able to set up a successful conference.