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).
Telephone service companies have created a special communication service without the need to use customer's equipment. It's called a "virtual number". It also has a text type of "virtual SMS center." Thanks to the virtual link you can make calls or send messages while connected to the equipment of the company.