... transmission. It has 4 E1 interfaces (BNC, 75OHM), 1+1 optical interfaces (FC), single mode, double core, and 4 10/ ... used in telecom carrier, power supply, railway, irrigation works, oil, bank system etcThe equipment enjoys high flexibility, modularity and scalability ... has echo tone, busy tone, and ring signal.Uplink port: Optical transmission distance is more than 30KM without repeat. E1 interface ...