Fiber port: single core fiber distance 40km The local end can display the fiber connection status of the remote device； Voice port supports FXO and FXS port, Support FXO/FXS, Magnet telephone Interface, FXO port docking with program-controlled switchboard, FXS port connected to the user's telephone; 1~4 or 1~8 channel Voice access, Voice FXO / FXS interface, support for caller ID / reverse polarity billing / fax function; Support various sites mutual number allocation function； External AC220/5-12V power adapter, can also be external DC-48V/5-12V power adapter； Telephone interface with lightning protection, lightning reached IEC61000-4-5 Short circuit current wave 8 / 20μs, the peak output voltage 6KV open standards.