... data standards in China.2 the stand-alone relay serverNo need the telecom carries agreement, use stand-alone relay server, with 3G sim ... screen Local Storage: 8M SD , HDD optionRecord mode: Manual , alarm ,timed Audio intercom : One channel BNC Two-way intercom, aideo ... u PNP , PPPoE, DDNSAlarm in/out : 1channel Sensor in ,1channel alarm out,( on , off, earthing)PTZ serial : 1 channel RS485, support ...