Cisco - expansion module - 56 ports

The Cisco ONS 15454 SONET 56-port DS-1/E1 card provides 56 DS-1 interfaces operating at 1.544 Mbps received over 100-ohm nominal twisted-pair cable or 56 E1 interfaces operating at 2.048 Mbps over 120-ohm nominal twisted-pair cable. The DS-1 and E1 interfaces are used for terminating transport signals within a central office or customer premises.