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).
This program allows you to control the use of the telephone, how many minutes you talk, where you have called, what amount of data is downloaded and so on. Thus, it helps you to fit in the framework of the contract conditions. The program is mainly used in mobile phones.