... has 4 E1 interfaces (BNC, 75OHM), 1+1 optical interfaces (FC), single mode, double core, and 4 10/100Mbps Ethernet interfaces, ... port: Optical transmission distance is more than 30KM without repeat. E1 interface : 4 E1s, 75Ω BNC connector. RS232 data interfaces: ... interface card: providing 4 channel 10/100 Base-T Ethernet bridge, support VLAN. Data Service ports: SpecificationsE1 Port l Port number: ...