◆ Provide 4 E1 digital interface
◆ Provide 4-channel with 100M Ethernet interface.
◆ On the channel with 1-16 telephone interface (available on the business needs of different users 　 　　different ones matching the telephone interface).
◆ Speech Interface support CND and anti-Signals.
◆ On small size, looks beautiful, easy installation and operation.
◆ On improving the status display, easy maintenance and management.
◆ On adapt to a variety of environmental -48VDC or 220VAC power supply.

Optical Interface
　 a） Bit rate：155.52Mbps±20ppm
　 b）Code pattern : NRZ+ Scramble
　 c）transmission optical power：> -5dB ～-17dB
　 d）Receiver sensitivity：> -36dB

Ethernet Interface
　 a) Interface ：10/100Base-Tx；
　 b) Interface specification: conform to         IEEE-802.3u standard
　 c) Interface rate: 10/100M self-adapting
　 d) Interface connector ：RJ-45。

E1 Interface
Nominal E1 Interface，Conform to ITU-T G.703、G.704 suggestion
　 a) Bit rate：2048Kbps±50ppm
　 b) Code pattern：HDB3
　 c) Interface impedance：75Ω
　 d) Interface Characteristics： Conform to G.703、　　G.742and G.823 standard
　 e) Frame Structure ：no frame structure

User and interface loop
　　Speech Interface : speech characteristics with 　the<<Ministry of Posts and total telephone 　exchange switch equipment Technology Standards>>
　a) Impedance：600Ω
　b) Insertion loss：-3±0.75dB
　c) Frequency：300～3400Hz(-0.6～+3dB)
　d) Noise：≤63.7dBmop
　e) crosstalk attenuation：≥65dB
　f) Subscriber Line loop resistance of less than 3K 　　Ω (walkie-talkie)
　g) Feed voltage：48V；
　h) Feed current：20~50mA；
　i)  15V ringing： plus or minus 15V AC90

External dimensions
　 Standard 19-inch 1U structure：438×215×45mm
　 Power supply
 　 　 Input:DC -48V（±20%）or AC 220V
 　 　 Output:±5V（±5%） ringing 75VAC
 　 　 Power:≦7W