... DDNS IP modem, RS232 modem, GSM IP modem, GPRS data modem, data terminal,GPRS DTU, TCP/IP modem, Support transparent data transfe, gprs ip modem, gsm modemgprs modem with rs232 ... , telemetry, finance, POS, water supply, environment protection, post, weather, etc. High-performanceSupport TCP server and support multi TCP client connection(optional ...