... standard TCP/IP protocol stack, i/o 3.Support transparent data transfer 4. Support 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 ... timeSupport multi online trigger ways, including SMS, ring and data. Support link disconnection when timeoutSupport dynamic domain name(DDNS) and IP ...