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).
Cisco 6921 is inexpensive business class IP phone model supporting video connection (Cisco UC Phone 6921, Standard Handset).
Cisco 6921 IP phone supports up to 2 lines has full-duplex loudspeaker, supports call holding on each line, hold, transfer, conference keys, tricolor indication of line condition, functional keys for simplified use of IP phone functions.