linux3g无线上网卡，拨号上网，chat，ppp等所需配置文件和usbmodemswitch全部整合-linux3g wireless modem, dial-up Internet, such as chat, ppp desired configuration file and usbmodemswitch all integrated

XMODEM协议是一种使用拨号调制解调器的个人计算机通信中广泛使用的异步文件运输协议。这种协议以128字节块的形式传输数据，并且每个块都使用一个校验和过程来进行错误检测。-XMODEM is asynchronous file transport protocol to use a personal computer dial-up modem communication widely used. This form of transport protocol data block of 128