1.4E1 PDH fiber optical Equipment 2.1+1 optical interfaces (FC) 3.with 48Vdc and 220Vac 4.4 10/100M Ethernet interfaces, 2 R ... 4 E1 interfaces (BNC, 75OHM), 1+1 optical interfaces (FC), single mode, double core, and 4 10/100Mbps Ethernet interfaces, with order ... port: Maintenance phone has echo tone, busy tone, and ring signal.Uplink port: Optical transmission distance is more than 30KM without repeat ...