Visual voicemail has access to a visual interface, which shows the list of playable voicemail messages and sometimes can include decryption of those messages.
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).