A European format for digital transmission. E1 supports signals at 2 Mbps (32 channels at 64Kbps, with 2 channels reserved for signaling and controlling), versus the T1, which carries signals at 1.544 Mbps (24 channels at 64Kbps).
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.