说明：  CRAS是一个MFC类，它封装了Windows 的远程访问服务（Remote Access Service）。这个类的主要优点是通过LAN便可以连接到Internet，并且不用安装RAS，因为RAS DLLs是动态加载的。
(CRAS is a MFC class that encapsulates the Windows Remote Access Service (Remote Access Service). The main advantage of this class through the LAN will be able to connect to the Internet, and do not install the RAS, because the RAS DLLs are dynamically loaded.)