ME99T is a GPRS/CDMA IP DTU Modem that integrates TCP/IP protocol. It contains IP module and GPRS/CDMA module. GPRS module adopts industrial SIEMENS GPRS module, which is compatible with all AT command sets of SIEMENS GPRS module; IP module is based on ARM7 core TCP/IP protocol stack control chip, with the software interface of AT+I command set. Two modules are relatively independent, but all standard AT commands are transparently passed to GPRS/CDMA module through IP module. ME99T is generally suitable for host host without TCP/IP protocol stack and serial communication. It can not only implement simple TCP and UDP connections, but also establish up to 10 TCP connections through instruction system and other complex applications, or directly communicate with GPRS/CDMA module to implement SMS, voice and other applications.