The ADSL repeater can extend the transmission distance from the central office terminal to modems of subscribers and make sure the Internet access rate as follows: a). For an ordinary ADSL system: The use of a repeater can extend the distance (3.5m) from the DSLAM to a Modem to 5.5km ~6km, and meanwhile can support ordinary voice service. b). For an ADSL2+ system: The use of a repeater can extend the coverage distance of the DSLAM to 6 ~ 7km, and meanwhile can maintain the ordinary voice service. It prevents service churn due to far line distance and poor quality. 2.2 Remote Power Supply Both the input and output voltages are not specific to positive or negative polarity. The output line has already been configured in the junction box upon delivery. An independent pair of cables is used for supply power for the repeater.