4 PCM Voice Telephone Ethernet over Fiber Optic Media Converters Singlemode 20Km
Ringing frequency: 17~60HZ. Ringing frequency: 22~28HZ. Ethernet RJ45 port specifications Bell flow: AC90 plus or minus 15V. Balanced noise: ≤63.7dBmop. Rate: 10M/100M, full duplex, half duplex fully adaptive.